Talk:Evolution/Archive 53
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Terribly confusing section
Natural selection most generally makes nature the measure against which individuals, and individual traits, are more or less likely to survive. "Nature" in this sense refers to an ecosystem, that is, a system in which organisms interact with every other element, physical as well as biological, in their local environment. Eugene Odum, a founder of ecology, defined an ecosystem as: "Any unit that includes all of the organisms...in a given area interacting with the physical environment so that a flow of energy leads to clearly defined trophic structure, biotic diversity, and material cycles (ie: exchange of materials between living and nonliving parts) within the system."[111] Each population within an ecosystem occupies a distinct niche, or position, with distinct relationships to other parts of the system. These relationships involve the life history of the organism, its position in the food chain, and its geographic range. This broad understanding of nature enables scientists to delineate specific forces which, together, comprise natural selection.
This paragraph needs rewriting, it is pretty opaque. Tim Vickers (talk) 19:19, 15 February 2010 (UTC)
Lead outline
Lets think about what the lead should do.
- Three vital parts to the lead
- Define evolution.
- Say how evolution works (mechanisms) - production of variation, natural selection and drift acting on variation.
- Say what evolution does (outcomes) - adaptations and speciation.
- Suggestions? Maybe if we focus on the broad outline we can make some progress. Tim Vickers (talk) 23:31, 15 February 2010 (UTC)
Well the more I reflect I like the suggestion of Thompsma of addressing macroevolution first and then address microevolutionary approaches to address the gradual changes mechanistically responsible for macroevolution over prolonged time. It makes since to address how evolution explain earth's history of life, the tree of life, biogeography, etc. then work on mechanisms?? Emphasize nat sel as Thompsma suggest as more organisms are produced than that which can survive because of limited resources such there is a competition for existence and stabilizing, disruptive, and directional selection. Nat sel explains both adaptations and evolution. Discuss macroevolutionary evidence for common origion and descent or events-standard genetic code, endosymbiosis, explain simple cladistics of monophyletic groups with primitive and derived traits as we explain the tree of life. Then move into how we can now measure microevolution as shifts in the genetic-phenotypes in populations through successive generations-pop. genetics approach. I can see a compromise that would salvage parts of the old just in a new order. Something to think about. GetAgrippa (talk) 00:40, 16 February 2010 (UTC)
So you'd prefer:
- Define evolution.
- Say what evolution does (outcomes) - History of life. Common descent. Adaptations and speciation.
- Say how evolution works (mechanisms) - Production of variation, natural selection and drift acting on variation.
- Seem fair? Tim Vickers (talk) 02:07, 16 February 2010 (UTC)
- But the issue then is how do we define evolution, Dobzhansky's shift in gene alleles, Futuyama's all pervasive change, in terms of Darwin's ideas of common descent and natural selection. OR a little of both. The fact of evolution that biological change is empirically obvious and this change is pervasive and at multiple levels such as complex behaviors. Then Evolution theory as Darwin's ideas of common descent and nat sel that laid the framework for all modern theory and the tree of life. Really Thompsma is correct we have been defining evolution by the outcome of the processes of evolution (genetic changes in populations), but evolution is really the processes of nat sel, genetic drift, and gene flow and how they influence the phenotypes (Thompsma is correct it is the phenotype) populations through successive generations. Then in particular how nat sel produces adaptations to overcome environmental challenges and this process explain the incredible diversity of life past and present and it is the driving force (happy Thompsma hee,hee) of adaptive evolution. Really the processes of evolution are mechanisms of evolution as these forces (dang did it again)act on the population (not the gene) and phenotypes and we measure the outcome via pop genetics and genotypes. Pop genetics and genomics are tools to explore and explain how these processes or mechanisms have influenced populations not the definition. These tools can examine microevolution and genetic shifts and macroevolution and larger genomic changes. GetAgrippa (talk) 03:23, 16 February 2010 (UTC)
- You seem to have lots of ideas there, could you try to sort them out into a coherent first paragraph? I think we all agree that we need to start with a reasonable definition, so I'll start the section below and everybody can then add to it. Tim Vickers (talk) 04:42, 16 February 2010 (UTC)
First paragraph: defining evolution
In biology, evolution is change in the history of life. Earth's history is approximately 4.5 billion years old. A precise date of life's origins remains a mystery, but free living cells were already starting to evolve 3.8 billion year ago. Through time, there have been major evolutionary transitions, but the basic principals remain the same. Every living individual is made of cells. Cells and individuals naturally come in varieties and they are always members of populations. Individuals exchange genetic material and they reproduce. Populations may experience growth periods when new environments are colonized and individuals multiply, but once the resource capacity is reached the number of individuals in the population will stabilize and tend to remain constant in number over time. Each generation, individuals within such a population will produce more offspring than can be sustained by the resources available. Only a select number of individuals can survive to a mature reproductive age. Individuals produce children that look like their parents as they pass on heritable genes that regulate their growth and development. Different genes produce different parts with unique physical appearances, such as brown hair, and these are called traits.
- Specific comments.
- Change in what in the history of life? Number of organisms, distribution of organisms? If people build a new city and move into it, is this evolution? This "definition" is so general as to be meaningless.
- I put this in because I thought is was a very general statement that you see in many textbooks. I've seen this repeated many time over and over - Evolution is change. I'm certainly open to changing this.Thompsma (talk) 20:38, 16 February 2010 (UTC)
- "major evolutionary transitions" sound important, but are undefined and unexplained.
- I took this from Eors Szathmary and John Maynard Smith's book[1]. The major evolutionary transitions are things such as moving from RNA world to DNA, from cellular to multi-cellular, from multi-cellular to organisms, from organisms to colonies, from colonies to societies and so on. Their book examines each of these transitions in evolution and the basic theme is that higher-level group selection trumps selection operating at lower levels of organization. You are correct that it isn't defined, but I think that many people understand what a transition is - such as moving from water onto land?? Perhaps not - I'll think this over.Thompsma (talk) 20:38, 16 February 2010 (UTC)
- Yes, I've read that book and I recognised the phrase, but your reader will hear a "Major" idea mentioned once in the lead and then discarded with no further explanation.
- There are many ideas in the current lead that come with no further explanation. There is this type of open ended critique being launched here that can be said equally for what is currently posted in this article. This is the lead - it doesn't need to go into depth - the reader can move on. If I haven't done a good job in describing this - then reject what I put. Let's try something new.
- The "basic principals" of what exactly? Of the history of life in general? Of major evolutionary transitions? Of life's origin?
Relates to previous comment - I was thinking basic principals meaning natural selection.Thompsma (talk) 20:38, 16 February 2010 (UTC)
- If you mean "the basic principles" of evolution, then the list of facts that follow are not principles of evolution, they are conditions that produce evolution.
- A bacterium isn't made up of cells.
There is no such thing as a bacterial cell?? I understand where you are going: "Every living individual is made of cells." There has to be some latitude here - every species is made of cells. When I first wrote this I was thinking of the difficulty in terms of prions or other things that are not cellular in the strict sense.Thompsma (talk) 20:38, 16 February 2010 (UTC)
- Why even mention cells? This is superfluous and inaccurate information (most organisms are unicellular) that will only confuse your reader.
- "Resource capacity" is undefined jargon.
Is it? I think it kinda defines itself - once populations reach a threshold the number of resources become limited, i.e. - the carrying capacity of a population. There are going to be lots of bits that are not fully disclosed - we could start by defining word by word each little bit - but this wont get us very far.Thompsma (talk) 20:38, 16 February 2010 (UTC)
- Ask five people on the street what "resource capacity" is. You need to try to write more simply - ..but since resources are limited, the number of.. would be better
- What are "heritable genes"? What is an "unheritable gene"?
[2]Thompsma (talk) 20:38, 16 February 2010 (UTC)
- Thanks, but I can use a search engine myself. I was asking why you use the adjective "heritable" in this sentence? "they pass on heritable genes" seems rather redundant as a phrase.
- The definition of traits is very unclear.
"In contrast to characters, traits are attributes that occur in some but not all representatives of a terminal lineage or monophyletic group."[3] "Many, if not most, morphological characters describe variation in quantitative traits (e.g., differences in size, shape, or counts of serially homologous structures), regardless of whether systematists choose to code them quantitatively or qualitatively (Stevens, 1991; Thiele, 1993)."[4] There are genotypic and phenotypic traits. In systematic studies there are characters with states and the state describes the trait. For example, hair color is a character and the state brown, black, blonde are the different states or descriptive traits of the hair color. Traits can be discrete (as before) or continuous (e.g., 0-1cm, 1-2cm, 2-3cm diameter). Characters are described features that are hypothesized as homologous. In genetic data the character is the position in the alignment of the genetic sequence and the state (or trait) is the nucleotide that sits in that position. I tried to simplify this without going into details about the genotype and phenotype. Most simple texts refer to morphological traits (such as brown hair color) because this what a trait is in its simplest form.Thompsma (talk) 20:38, 16 February 2010 (UTC)
- "Different genes produce different parts with unique physical appearances" - very unclear, think about what you mean and put it in simple words.
- General comments
- This is a list of facts that fails to tell the reader what the significance of the facts are.
- It is an attempt to synthesize the background that is needed to understand what follows.Thompsma (talk) 20:38, 16 February 2010 (UTC)
- In writing we call that an "infodump". Try to tell a story - "A and B are facts, these cause event C, which in turn causes D. D also requires E and the combination of D and E are called X." Instead you have written a paragraph that says "A, B, C, D, E, F and G are facts."
- It is an attempt to synthesize the background that is needed to understand what follows.Thompsma (talk) 20:38, 16 February 2010 (UTC)
- The first paragraph skips from the history of life to the list of population factoids without mentioning common descent or even giving a basic outline of what has happened in the history of life. Instead abiogenisis is put center stage, a topic that is irrelevant to evolution.
- This is an attempt to put emphasis on the depth of time over which evolution has been occurring. I was following the lead from a suggestion that someone made above about starting with the depths of time and also used the technique that was used by Eors Szathmary and John Maynard Smith in their book about evolution, which starts out talking about abiogenisis in context of the evolution of replication and the cell. You are correct that it is a bit disjointed - so perhaps we can build upon this? The idea I was working with here is to impress upon the reader the depth of time over which evolution has operated and the levels of organization in life - from genes, cells, organisms to populations. Can we just modify parts? Or have I failed completely?Thompsma (talk) 20:38, 16 February 2010 (UTC)
- Perhaps if you try writing a point-by point outline? This draft does rather read like you sat down and wrote it as a flow of consciousness, with no overall structure. Tim Vickers (talk) 20:57, 16 February 2010 (UTC)
- We do not have to use my draft - it was just an idea that I contributed to here. If people think it is crazy - put some alternatives, or modify it. This semester I am TA'ing a course on evolution and we are using "Strickberger's evolution: the integration of genes, organisms and populations". If you look at this text[5] (just as an example):
Part 2: Origins: The enormity of time
- Chapter 4: The origins of cosmic structures and chemical elements
- Chapter 5: Origin of Earth
- Chapter 6: molecules, protocells and natural selection
- Chapter 7: From molecules to life
- Chapter 8: Origins of cells and the first organism
Here we have an example of an evolutionary text - a very good one I might add - that seems to follow this sort of organization. I'm putting this here to show that I'm not crazy for organizing my ideas in this way. It was also the model addopted by Szathmary and Smith in their book. Someone posted - why even talk about cells!! Where are these critiques being launched from? This is biology - cells are very important in the levels of organization of study. I might recommend that you start looking at Brian Hall's publications (one of the authors on the Strickberger's evolution text). He places a very strong emphasis on natural selection acting on populations of cells.(e.g., [6])
- Not sure who made the above comments, but this is very inferior to the existing opening paragraph as an explanation. "Populations may experience growth periods" completely misstates the essential issue of natural selection that population growth always exceeds supply, so is kept in check by resource limitations. It seems to miss the basic point that evolution is a continuing process, though divergence and speciation don't always occur. . dave souza, talk 19:45, 16 February 2010 (UTC)
- Ah...I mention resource limitation. Also this is about founder events - Malthus' laws of exponential population growth. It is not until carrying capacity is reached that resource limitations start having their effect - this is the premise behind r/K-selection.Thompsma (talk) 20:38, 16 February 2010 (UTC)
- What I have written may be inferior in its rough sketches, but I hope that people start to realize the conceptual problems with the existing article. If what I have put up doesn't work for people - propose something else. The current version is clearly presenting an incorrect concept of evolution:
- Reading some of Thompsma's comments inspired me to dust off the Gould opus "Structure and Function" and refresh my memory, and what struck me was his comments concerning Sewall Wright and genetic drift and the "hardening phase" of the modern synthesis. The emphasis on adaptions and placing population genetics in its proper perspective. He describes Wright belief and arguments supporting drift can also be adaptive by interacting peaks of similar demes. Another striking feature is how the Modern Synthesis was a "Limited Consensus", which from the debates above and below apparently still continues. Although gene flow migrations are generally homogenizing, HGT and hybridization both have published examples adaptive evolution and speciation-so keept this neutral. Rather than get envolved in the Species, population, etc. debate of level or unit of selection, just acknowledge evolution acts on cells, populations of cells, species, demes, clades (NPOV) because it seems the literature supports multilevels as Thompsma suggest. Perhaps just sort out the facts in the article but just mention all equally in NPOV and then sort out and weight things later. We could propose a generic definition that mentions mechanisms and outcomes. Then fill in the detal between in the body of the paper. Definition: Evolution is the interactive forces of nat sel, genetic drft, and gene flow acting on genes, cells, populations of cells, species, demes, and clades within the biosphere producing the tree of life through common descent,adaptations, and the diversity of life. Just a global generic definition that is truly neutral and mentions mechanisms of evolution and outcomes of evolution-biosphere, mention tree of life (has morphologic and genetic nested implications) and common descent, adaptations, and diversity. Nested is ecology and macro and micro changes. There is no mention of phenotype or trait or genes or time but from this generic start we can develop the detail of traits and genes, or primitive and derived traits and fill in the details in between. Admittedly a really different approach, but thought I would air the ideaGetAgrippa (talk) 04:34, 17 February 2010 (UTC)
- Okay, Okay! I was trying to think out of the box and apparently I was so far out I followed Jason in my search of the golden fleece! Thanks for being polite. GetAgrippa (talk) 03:00, 19 February 2010 (UTC)
Second paragraph: natural selection and mutation
In 1859 Charles Darwin published a scientific treatise on evolution that explains the origin of species by means of natural selection. The theory is based on three factual observations of life that include: 1) all living things come in varities, 2) the overproduction of offspring as individuals multiply means that many perish from the population, 3) heritability and preservation of traits of inviduals are continually subject to the conditions of life. The origin of species is an inevitable consequence of these three facts of nature. However, there are different kinds of natural processes that can cause populations to diverge into new species. Random mutations, for example, accumulate in genes, either during sexual reproduction, during replication, or as DNA is structurally altered by things in the physical world, such as background radiation. Many of the smaller physical mutations in DNA are neutral with respect to the larger consequences in the life of the carrier. Mutations can also be harmful or beneficial, such as one gene creating duplicate copies of itself. These sorts of mutations accumulate and sort into populations and generate new traits and varieties of cells, organisms and species.
- Specific comments
- Darwin and Wallace
- Is it really necessary? We all know that Darwin founded the theory years before Wallace as he passed unpublished abstracts along to his colleagues.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- Mentioning Darwin isn't necessary to explain natural selection and mentioning Darwin alone repeats a common error. I'd personally miss him out entirely from a paragraph that is aimed at explaining concepts.
- Is it really necessary? We all know that Darwin founded the theory years before Wallace as he passed unpublished abstracts along to his colleagues.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- What is a variety?
- How simple does this have to be? If people don't know what varieties are - where do we begin?Thompsma (talk) 21:29, 16 February 2010 (UTC)
- You could just say "organisms vary from one another", saying "organisms come in varieties" sounds like you are sorting organisms into distinct types.
- How simple does this have to be? If people don't know what varieties are - where do we begin?Thompsma (talk) 21:29, 16 February 2010 (UTC)
- "heritability and preservation of traits of inviduals are continually subject to the conditions of life" - very unclear, what does this mean? What are "conditions of life"? Are you trying to explain that some varieties are better suited to survival and reproduction than others?
- I'm trying to impress the concept of phenotypic plasticity (e.g., [7]) without going into the details. This is about individuals in ecosystems and environments where the conditions for life can alter the developmental process by induction to alter the shape and form of emergent traits.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- Why on earth bring phenotypic plasticity into the lead? This is a simple introduction!
- I'm trying to impress the concept of phenotypic plasticity (e.g., [7]) without going into the details. This is about individuals in ecosystems and environments where the conditions for life can alter the developmental process by induction to alter the shape and form of emergent traits.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- You haven't actually managed to say what the outcome of natural selection is, just given a rather confusing list of the requirements for it to occur.
- It follows closely what I see in other books and texts describing what natural selection is. I can't really do any better than this.
"The basic formulation, or bare-bones mechanics, of natural selection is a disarmingly simple argument, based on three undeniable facts (overproduction of offspring, variation and heritability) and one syllogistic inference (natural selection, or the claim that organisms enjoying differential reproductive success will, on average, be those variants that are fortuitously better adapted to changing local environments, and that these variants will then pass on their favored traits to offspring by inheritance)." (Stephen J. Gould, 2002)
- This same theme has been told over and over again in every classical book and paper on natural selection. I really don't see what the difference is from what I present and what has been said elsewhere in this respect.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- You'd need a sentence saying something like "If these conditions are met, those organisms that vary in ways that help their struggle for existence will tend, over generations, to replace those that are less well-suited." Presently you go straight from the preconditions for natural selection to the emergence of species, without finishing your explanation of selection.
- This same theme has been told over and over again in every classical book and paper on natural selection. I really don't see what the difference is from what I present and what has been said elsewhere in this respect.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- The origin of species does not follow from these three facts since once variation is exhausted, evolution would come to an end. Natural selection alone cannot produce evolution.
- Without going into all the nitty gritty details I say "all living things come in varities" - later I describe how this occurs via mutation.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- Well no, since you fail to link the two.
- Without going into all the nitty gritty details I say "all living things come in varities" - later I describe how this occurs via mutation.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- You appear to be saying that random mutation can cause the origin of species. Hopeful monsters?
- I'm not saying this at all, but I see your point. It is a simple grammatical error that can be fixed easily enough.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- "things in the physical world" - why the "physical world"? Are organisms not part of the physical world? What isn't in the physical world?
- Of course - just bringing it out of the theory in mind to remind people that these things are subject to physical forces.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- "Many of the smaller physical mutations in DNA are neutral", the size of a mutation is only peripherally relevant to its phenotype. Polyploidy or aneuploidy can be neutral, while a single base change can be lethal.
- Taking this too literal. It is a simple explanation referring to the silent synonomous mutations through the redundancy in the genetic code - such as that used in the infamous McDonald-Kreitman test.[8]Thompsma (talk) 21:29, 16 February 2010 (UTC)
- Just delete "smaller", it isn't needed and isn't accurate. Similarly, why "physical mutations"? This implies that a set of mutation exist that are not physical. Remember - omit needless words
- Taking this too literal. It is a simple explanation referring to the silent synonomous mutations through the redundancy in the genetic code - such as that used in the infamous McDonald-Kreitman test.[8]Thompsma (talk) 21:29, 16 February 2010 (UTC)
- "neutral with respect to the larger consequences in the life of the carrier" - again, very unclear.
- Do you really want me to explain neutral theory? This seems very simple and clear to me - but I could be wrong.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- No, but your sentence doesn't explain what "larger consequences" are, and "with respect to" is bad writing.
- Do you really want me to explain neutral theory? This seems very simple and clear to me - but I could be wrong.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- You say that mutations can be "harmful or beneficial, such as one gene creating duplicate copies" - the reader will be unable to see if this example refers to the first class, beneficial, or the second, harmful. In fact this example is not an example of either of the two classes of things you are trying to explain.
- I'm following through on Ohno's 'Evolution by Gene Duplication' model - where the theory suggests (and tests have shown this to occur) that the redundant duplication of genes frees one up from the functional pressures as one version takes control.[9]
- Gene duplications can also be harmful, such as oncogenes.
- That was my point - genetic duplication (polyploidy, oncogenes, or redundant genetic duplication) can be either harmful or beneficial. I didn't go into the details - but this is what I as thinking when I wrote this.Thompsma (talk) 00:05, 17 February 2010 (UTC)
- Gene duplications can also be harmful, such as oncogenes.
- I'm following through on Ohno's 'Evolution by Gene Duplication' model - where the theory suggests (and tests have shown this to occur) that the redundant duplication of genes frees one up from the functional pressures as one version takes control.[9]
"After duplication, previously disfavoured binding site configurations evolved that divided the regulation of the ancestral gene into two specialized genes, one of which ultimately became one of the most tightly regulated genes in the genome."[10]Thompsma (talk) 21:29, 16 February 2010 (UTC)
- "These sorts of mutations" - what sort of mutations? you listed three types.
- I gave examples. You cannot elaborate on everything here in the lead - it is a general overview.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- If you are trying to explain natural selection, you mean beneficial mutations.
- I gave examples. You cannot elaborate on everything here in the lead - it is a general overview.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- "These sorts of mutations accumulate and sort into populations" - how does this occur, you have not linked this to natural selection or even mentioned genetic drift.
- No, but I do talk about individuals exchanging genetic material in populations in the preceding paragraph.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- Genetic exchange does not alter allele frequency.
- No, but I do talk about individuals exchanging genetic material in populations in the preceding paragraph.Thompsma (talk) 21:29, 16 February 2010 (UTC)
- General comments
- This paragraph would greatly benefit from dividing the processes you describe into those that generate variation and those that act on populations to reduce variation.
- Seriously, this proposal is a muddle compared to the existing second and third paragraphs, which divide processes that generate variation from those that act on populations to reduce variation. Have you pointed to any serious flaws in them, and can we review the wording to achieve what you want rather than bringing in Darwin etc. at this stage? . . dave souza, talk 21:50, 16 February 2010 (UTC)
- Discussed at great length above. There are serious flaws in the existing version - many of them. The existing version gives a reductionist view that looks at the gradual accumulation of genes leading to species over long periods of time. It is simple in its formulation but this is not how most evolutionary biologists have written that evolution works.Thompsma (talk) 23:35, 16 February 2010 (UTC)
- Why not use the definition I proposed above of mechanims and outcomes: Definition: Evolution is the interactive forces of nat sel, genetic drft, and gene flow acting on genes, cells, populations of cells, species, demes, and clades within the biosphere producing the tree of life through common descent,adaptations, and the diversity of life. Emphasize the processes and outcomes first, then parse out phenotype and work our way down to detail of genes, gene networks, and genomes. There is no mention of time scale just evolution explains life on this planet so we develop the details in the body of text. This eliminates the reductionist emphasis and takes a global stance of the biosphere and all life. The wording needs work but what of the idea??GetAgrippa (talk) 16:06, 17 February 2010 (UTC)
Editing the new version
Suggestion: How about focusing this section more on mutation and DNA, with the below wording? Also I don't think the gene expression link is helpful to many.
- Evolution is the product of two opposing forces: processes that constantly introduce variation in traits, and processes that make particular variants become more common or rare. A trait is a particular characteristic such as eye color, height, or a behavior that is expressed when an organism's genes interact with its environment. Genes vary within populations, so organisms show heritable differences (variation) in their traits. Physically, genes are part of the polymer sequence of an organism's DNA (or, for some viruses, RNA). The main cause of variation is mutation, which changes the sequence of a gene. Altered genes are then inherited by offspring. There can sometimes also be transfer of genes between species.
Narayanese (talk) 20:28, 20 February 2010 (UTC)
Third paragraph: Speciation and adaption
Over time populations become fragmented as individuals are spatially isolated or ecologically segregated from other members of their species. Once isolated, populations often experience a new period of rapid growth as individuals are able to exploit their new environments and available resources. Some populations are more successful than others and many go extinct. Each generation in the struggle to survive, some individuals posses certain traits that give them a slight advantage over those that perish. Inherited traits of those that survive are non-randomly selected as they become adapted for the functions that allow these individuals to live successfully in their populations and environments. These natural mechanisms explain the evolutionary origins of species and the preservation of varieties through a common line of descent. These processes have been sustained over billions of years to create the biodiversity that is living on this planet.Thompsma (talk) 07:32, 16 February 2010 (UTC)
- Specific comments
- "spatially isolated" and "ecologically segregated" are jargon
- What is the significance of rapid growth in isolated populations? Why are you telling the reader this fact?
- "Some populations are more successful than others and many go extinct." - extinction is not usually seen as a success, try saying "while others", so it is clear that you are comparing two different outcomes, not expanding on a single outcome.
- "Each generation in the struggle to survive, some individuals posses certain traits that give them a slight advantage over those that perish." - Ungrammatical. I'm not sure what this means, are you going back to trying to explain natural selection again?
- "Inherited traits of those that survive are non-randomly selected as they become adapted for the functions that allow these individuals to live successfully in their populations and environments. " - again, very unclear, what are "they" the traits or the individuals? You don't make it clear that this occurs over generations, instead you have worded it to say that this change in traits is a process that occurs in "those that survive".
- General comments
- Very muddled paragraph, hard to comment on its organisation since the writing is so opaque that the central ideas are not immediately apparent.
General discussion
- I'm confused by the big blurb, you proposing this wording change the intro on the main Evolution page? Also I'm not sure what you mean by "Anagenesis and cladogenesis are like micro-evolution and speciation(sic)." As the FAQ states "The article doesn't equate the two, but merely recognizes that they are largely or entirely the same process, just on different scales." — raeky (talk | edits) 08:01, 16 February 2010 (UTC)
- Hi raeky - there was lots of discussion about this above. When I wrote that the two are like one another - I was reading this from Willi Hennig in his classical book Phylogenetic Systematics and he makes the exact same comparison - his list of comparison was even longer. You've missed the entire discussion above where we clarified that in the history of evolutionary thinking that these are not "...largely or entirely the same process, just on different scales." Many evolutionists and philosophers have been sharp to point out (including Alan Templeton in the quote I posted just above) that there are often different explanations and processes responsible for speciation/cladogenesis than is occurring within the micro-evolutionary processes among populations/anagenesis. This was the principal behind Willi Hennig's cladistics - where he said what is taking place in anagenesis is not important for the purposes of his taxonomic methods. His method of reciprocal illumination was used to test relations among species (cladogenesis). Ernst Mayr strengthened these metholodological principals through his many observations and understanding of population level phenomena in context of allopatry (or sympatry) and posited "for the new species to be truly successful it must be able to compete with larger, more diversified species". Many other authors since (see extensive list in discussions above - new and old publications) have repeatedly claimed that selection acts on the emergent properties of groups and species - that it is not a genetic only phenomenon. The theory of punctuated equilibrium and an expanded understanding of inclusive fitness explaining altruism within groups are based on these principals. Hence, we are trying to make a more inclusive NPOV article - one that moves away from the reductionist/gradualism only approach which claims that macroevolutionary processes are microevolution writ large (i.e., "...largely or entirely the same process, just on different scales.") to one that also considers what Stephen Gould, Edward Wilson and many other evolutionists and philosophers have been saying for the past century that selection can and does operate on a multi-level scale - from genes to species. In other words, natural selection is the differential survival among Darwinian individuals that replicate and interact. I'm using the term individual here in the extended philosophical sense - where species are also considered individuals (e.g., [11],[12],[13],[14]. Or as the last citation puts it: "Species are generally considered to be the basic units of evolution, and hence to constitute spatio-temporally bounded entities." (emphasis added)Thompsma (talk) 17:12, 16 February 2010 (UTC)
- Hey - I just noticed this morning that part of I wrote has been cut out which would answer some of your questions - for some reason parts were cut off!!! I don't have time to work on this now - I'll fix this later today.Thompsma (talk) 18:00, 16 February 2010 (UTC)
- The second and third paragraphs are still there, lower down in the page. Since your draft will need intensive editing, we need to take is in small pieces. Try to think about what are the essential facts and concepts that each paragraph should contain. Your work lacks structure and so lacks clarity. Tim Vickers (talk) 18:13, 16 February 2010 (UTC)
- Oh...okay - ooops, I see what has happened. I'll take a look at your feedback. I thought I would add one further quote from Brian Hall. Hall is a researcher at Dalhousie who has written extensively on developmental biology and I've met and talked to him numerous times. He is a very fascinating person who has lots of ideas about eco-evo-devo and selection acting on populations of cells:
- "We suggest that modularity can be viewed as being nested in a manner similar to Baupläne so that modules express unique sets of genes, cells, and processes. In terms of evolution, we conclude that natural selection can act on any of these hierarchical levels within modules or on all the sensory modules as a whole."[15]
- Again - we see an example of an active researcher in evolutionary biology who suggests that natural selection is hierarchical, emergent and acts on the whole of interaction rather than the parts.—Preceding unsigned comment added by Thompsma (talk • contribs)
- So, it's a view. To me it's puzzling as to how species pass on heritable variations if not through genes. This looks like an alternative view to describe briefly in the body of the article, rather than a mainstream view that should have most weight. . . dave souza, talk 22:21, 16 February 2010 (UTC)
- We briefly mention the possible application of epigenetics to evolution in the article, but this is currently too controversial as a hypothesis to include as anything more. Similarly, humans can undergo cultural evolution and pass on knowledge and traditions, but this isn't a widely-applicable phenomenon in biology. Tim Vickers (talk) 22:34, 16 February 2010 (UTC)
- Again - we see an example of an active researcher in evolutionary biology who suggests that natural selection is hierarchical, emergent and acts on the whole of interaction rather than the parts.—Preceding unsigned comment added by Thompsma (talk • contribs)
- All true. However, in context of multi-level selection - it is encompassed in a broader set of theory that has been largely accepted. Hence, the point I am making here is that the Dawkins proposal that genetic replicatio n is the fundamental unit of evolution is not generally accepted. The Dawkins gene centered view is what this article mostly presents - it isn't representative of the wider published views - historical or contemporary. It is mostly reductionistic and gradualism from a genetic stance. It isn't that I dislike these idea's - I'm a huge fan of Dawkins, but this article should be nonpartisan. Most contemporary evolutionists concur with the Gould and Lloyd[16] (and others) formulation that there are Darwinian replicators and Darwinian interactors. This principal applies generally to the concepts of selection acting above the genetic level - emergent properties of individuality. Populations, groups, and species are subjected to the principals of natural selection. This is neither a minority view, nor entirely theoretical - it is based on observational studies (as Mayr has claimed) and it has been published as an accepted hypothesis (see links I gave above on this discussion point). Douglas Futuyma gave a review of Gould's published ideas in this respect:
- "Gould's themes are that selection operates not only among organisms within species, but also at other levels (especially among species, thus accounting for macroevolutionary trends); that the heritable phenotypic variation arising within species is not "isotropic" but biased in certain directions, providing "positive constraints" on the direction of evolution; and that the vectors of change within species are cancelled by selection (or "sorting") at higher "tiers," chiefly by species selection and by mass extinctions. He articulates in extenso these familiar arguments in his familiar style, cementing them by empirical case histories and occasionally adding a gargoyle or two to face down his critics."[17]
- Gould isn't alone and this is the point I am trying to make in these revisions. This article is too reductionist and it seems to have been written by someone as radical as a saltationist - but in a complete 360.Thompsma (talk) 23:20, 16 February 2010 (UTC)
Historical outline in lead
The historical outline at present is simply wrong, and does not summarise the information in the historical section of the article.
The study of evolutionary biology began in the mid-nineteenth century, when research into the fossil record and the diversity of living organisms convinced most scientists that species changed over time. However, the mechanism driving these changes remained unclear until the theories of natural selection were independently proposed by Charles Darwin and Alfred Wallace. In 1859, Darwin's seminal work On the Origin of Species brought the new theories of evolution by natural selection to a wide audience, leading to the overwhelming acceptance of evolution among scientists.
Propose the following:
The study of evolutionary biology began in the early nineteenth century, as research into the fossil record and the diversity of living organisms convinced most scientists that there had been a series of changes in species over time. Evolutionary ideas remained unorthodox, and scientific establishments viewed species as fixed and purposeful. At first the theories of natural selection independently proposed by Charles Darwin and Alfred Wallace did not gain widespread support, but Darwin's seminal 1859 work On the Origin of Species convinced scientists and most of the public that evolution occurred and was a legitimate scientific subject.
Haven't checked through the existing sources, but the sources in the text should cover this. . . dave souza, talk 22:13, 16 February 2010 (UTC)
- You need to work in a sentence on Darwin and Wallace providing a mechanism for a known observation, otherwise good. Tim Vickers (talk) 23:48, 16 February 2010 (UTC)
"On the other hand, mathematicians ignorant (like Darwin) of the genetic underpinnings of heredity soon produced demonstrations that natural selection could have little real effect on species, and the whole idea fell into some disfavour, even in Darwin’s lifetime. It was rescued, ironically, by the mathematical modellers of the Modern Synthesis of evolutionary theory in the 1930s. Ronald Fisher, Sewall Wright and J. B. S. Haldane showed, among other things, that even small selective advantages could permanently affect evolution in populations. They brought back natural selection with a quantifiable vengeance, and it has been the primary focus of evolutionary research ever since."[18]Thompsma (talk) 01:30, 17 February 2010 (UTC)
The study of evolutionary biology began in the early nineteenth century, as research into the fossil record and the diversity of living organisms convinced most scientists that there had been a series of changes in species over time. Evolutionary ideas remained unorthodox, and scientific establishments viewed species as fixed and purposeful. At first the theories of natural selection independently proposed by Charles Darwin and Alfred Wallace did not gain widespread support, but Darwin's seminal 1859 work On the Origin of Species made a convincing argument that evolution occurred. Darwin's theory was initially rejected until the re-discovery of Gregor Mendel's study on the principals of inheritance and mathematicians of the early 20th century that quantified Darwin's theory through genetics.
I threw this alternative up quickly - gotta run for a bus.Thompsma (talk) 01:30, 17 February 2010 (UTC)
Accumulation of change
"Although the changes produced in a single generation are normally small, the accumulation of these differences over time can cause substantial changes in a population, causing the emergence of new species."
- This preceding sentence really bugs me. It is gradualism - take a population extend the accumulation of change over time and voila - a new species. If you read the discussion we had earlier I made it fairly obvious and clear that this goes against the prevailing view on the process of speciation. There is a fundamental difference between anagenesis and cladogenesis - or microevolution and macroevolution - or whatever you want to call it. Species are not stuck in place - they move about and biogeographic barriers form. Peripheral isolates are formed - genetic revolutions occur - there are so many things that happen and most studies done to date have rejected the notion that you can take anagenesis and simply extend it out through time to arrive at a new species.Thompsma (talk) 20:45, 16 February 2010 (UTC)
- Since I presume you're not a saltationist, your point is unclear. Could you state in a few words, with links for technical terms, what exactly you object to in the first paragraph as existing. . . dave souza, talk 20:52, 16 February 2010 (UTC)
- Read some of the earlier posts - this was already discussed at length. Of course I'm not a saltationist! I have never proclaimed to be anything in here. I'm trying to present a broader overview of evolution that isn't reductionist in its stance - already discussed at great length earlier in the discussion that lead to this new proposal. If anything I see evolution the way that Stephen J. Gould saw it - but there are certainly a few places were I find differences.
- Since I presume you're not a saltationist, your point is unclear. Could you state in a few words, with links for technical terms, what exactly you object to in the first paragraph as existing. . . dave souza, talk 20:52, 16 February 2010 (UTC)
- This preceding sentence really bugs me. It is gradualism - take a population extend the accumulation of change over time and voila - a new species. If you read the discussion we had earlier I made it fairly obvious and clear that this goes against the prevailing view on the process of speciation. There is a fundamental difference between anagenesis and cladogenesis - or microevolution and macroevolution - or whatever you want to call it. Species are not stuck in place - they move about and biogeographic barriers form. Peripheral isolates are formed - genetic revolutions occur - there are so many things that happen and most studies done to date have rejected the notion that you can take anagenesis and simply extend it out through time to arrive at a new species.Thompsma (talk) 20:45, 16 February 2010 (UTC)
"Although the changes produced in a single generation are normally small, the accumulation of these differences over time can cause substantial changes in a population, and some changes can cause the emergence of new species."
- The subset of changes that produce species in this version would be those events that produce reproductive isolation. Other changes might be those that produce adaptions. Tim Vickers (talk) 21:01, 16 February 2010 (UTC)
- As a suggestion, perhaps Thompsma's concern might be met by making the sentence a little more specific:
"Although the changes produced in a single generation are normally small, the accumulation of these differences over time can cause substantial changes in a population, and under some circumstances such as isolation of part of a population, the accumulated changes can cause the emergence of new species."
- Something on those lines. We could have a piped link in the isolation bit to allopatric speciation but that might be premature. . . dave souza, talk 21:27, 16 February 2010 (UTC)
- That aside is a bit confusing and allopatric speciations is only one example of a speciation mechanism, mentioning it in the lead would probably give it too much weight. We could explicitly note changes in tempo. Tim Vickers (talk) 21:51, 16 February 2010 (UTC)
"Although the changes produced in a single generation are normally small, the accumulation of these differences over time can cause substantial changes in a population, and some changes can cause the emergence of new species. Such evolution can happen quickly, such as during the rapid recovery of life on Earth from mass extinctions, while other changes are gradual and take hundreds of thousands of years."
- This is gradualism. Is it the really accumulation of these differences that cause speciation? What about founder effects? I think speciation has much more to do with the biogeography of the problem (cladogenesis) than the accumulation of mutations (anagenesis). There is mostly stasis in populations and species, it isn't until you have some sort of event (i.e., a barrier or a genetic revolution sensu Templeton) where you really see the new features really take hold. - Thompsma
- If you have a population and a small proportion of these organisms invade a new habitat, this is a founder event. If the old population and the new population do not differ in their inherited traits, are you arguing that because a founder event has occurred, the division of an ancestral population into two new populations of unequal sizes is an example of evolution? I think the normal view is that this small new population is not a new species until it has accumulated differences in its traits with the ancestral population. (If you put six rabbits in a box they do not suddenly become a new species of rabbit) Even the case where a population bottleneck is extreme and the sample of the ancestral population has a different allele frequency from the old population, until some unique changes accumulate they will still be "potentially interbreeding populations". This process of change is accelerated in a small population in a new environment, but it is still the accumulation of changes that creates a new species. I think you are confusing proximal and ultimate causes. Tim Vickers (talk) 23:40, 16 February 2010 (UTC)
- These principals always have to be put into the spatiotemporal/ecological/environmental context. It isn't that a founding population instantly becomes a new species - although this may theoretically occur and I vaguely seem to remember reading that it has been documented in a very rare case. There are a suite of other factors involved. However, the fact that genetic revolutions can and do occur in founding populations means that there is a process over time whereby these differences lead to a number of branching events. It is a different process than a single population gradually evolving into a new species that is different from the ancestral type. When averaged over time - the founder-flush model generates population level variation upon which selection acts. The founder model can accelerate the isolation process, but the new population is faced with the problem of facing extinction in relation to its ancestral population. The important part to the founder-flush model is that the population is usually peripheral and small in size. This means that there is going to be significant change in allele frequencies coupled with a group of individuals in a new environment. Moreover, there is increased levels of additive genetic variation when inbreeding occurs - meaning that the smaller isolated populations will be more responsive to the process of natural selection. The founder-flush model is one way in which a speciation event can occur. There are different speciation mechanisms, some are more common, all resulting in speciation events. Allopatry is another form where a biogeographic barrier leads to lineage divergence among the populations and fixation of reproductive isolation mechanisms (Mayr argued that sympatry could not be distinguished from allopatry - it is quite simply a matter of scale). The diversity of mechanisms leading toward speciation events are qualitatively and quantitatively different from following a single stable population over time where it becomes rather difficult for the simple accumulation of mutations to gradually lead to a new species. Alan Templeton gave a recent review of the founder-flush model.[19]Thompsma (talk) 01:08, 17 February 2010 (UTC)
Although the changes produced in a single generation are normally small, the accumulation of these differences over time can cause substantial changes in a population. Some changes cause a population of one species to split into two or more new species. New species can emerge quickly, such as during the Cambrian explosion, while others change gradually over millions of years. Similarities among species suggest that all forms of life are descended from a common ancestor through a long series of these divergence events, stretching back in a tree of life that has grown over billions of years.
- The preceding quote has some issues. Here is my suggestion:Thompsma (talk) 01:22, 17 February 2010 (UTC)
Although the changes produced in a single generation are normally small, these differences accumulate when populations become geographically isolated. Populations can diverge from one another through a variety of mechanisms that lead to speciation. The most commonly understood mechanism for speciation to occur is when populations become geographically isolated into sub-populations and independently accumulate enough differences over time. Similarities among species suggest that all forms of life are descended from a common ancestor through a long series of these divergence events, stretching back in a tree of life that has grown over billions of years.
- Should we also add a very general species concept:
Although the changes produced in a single generation are normally small, these differences accumulate when populations become geographically isolated. Populations can diverge from one another through a variety of mechanisms that lead to speciation. The most commonly understood mechanism for speciation to occur is when populations become geographically isolated into sub-populations and independently accumulate enough differences over time. These populations become species or speciate when they can no longer interbreed. Similarities among species suggest that all forms of life are descended from a common ancestor through a long series of these divergence events, stretching back in a tree of life that has grown over billions of years.
Thompsma (talk) 02:20, 17 February 2010 (UTC)
I'm pleased that we have started co-operating on improving the existing text, I hope this will be more productive than trying to re-write from scratch. Some comments
- That version states that evolution only happens in geographically isolated populations - "these differences accumulate when populations become geographically isolated". I don't think this is true, they just accumulate faster under conditions of isolation.
- Of course it is true - the difference between the two ideas is that the previous version described anagenesis in one population, whereas I'm talking of anagenesis in two sub-populations leading to cladogenesis. This is incipient speciation. There is of course ecological separation via sympatry, but this is the exception rather than the rule. Moreover, once you do a bit of actual ecological field work and study metapopulation structure, it becomes very clear that it is down to a matter of scale (temporal and spatial). How far must one be from the other before they are geographically isolated into allopatric units? What if there is a stream or some other feature of the landscape separating the two populations, yet they are only meters apart? What if there is a drought for five years that separates the populations, but later they reunite? These things are dynamically linked. There has been much discussion in the literature on the biogeography of this problem. This is the lead and so we should present the simplest case example (allopatry) and in the main article talk about the different modes of speciation.Thompsma (talk) 07:52, 17 February 2010 (UTC)
- Speciation is mentioned as something that occurs, but what it is not defined.
- The biological species concept (which almost everyone agrees is the most general): "Groups of actually or potentially interbreeding natural populations that are reproductively isolated from other such groups." (Mayr, 2001)
- "...populations become geographically isolated into sub-populations (i.e., groups) and independently accumulate enough differences over time (i.e., lineages). These populations become species or speciate when they can no longer interbreed (i.e., biological species).
When I wrote the section I was thinking about Templeton's cohesion species concept[20], but I also re-read some papers and notes that I had collected when taking a course on the plurality of species concepts with Mark Ereshefsky. Would you rather I write out: A species is defined as...?Thompsma (talk) 07:52, 17 February 2010 (UTC)
- The idea of defining a species is probably a good idea, but this is a minefield (as I'm sure you realise) will we just cause us problems down the line as other people object to the definition we use? Tim Vickers (talk) 05:58, 17 February 2010 (UTC)
- I think the first sentence second paragraph should mention that genes are also passed horizontally:
The basis of evolution is the passing of genes among populations and from one generation to the next. Genes produce an organism's inherited traits, with a trait being a particular characteristic such as eye color or height.
Do genes produce a trait? If I understand things correctly, genetic expression is regulated by internal and external induction factors that are environmentally contextual. For example, from the moment an embryo is implanted on the placental wall - pressure from resting on the mothers wall creates the first polar gradient during development. Genes within cells adjacent to the uterine wall are turned on and a protein gradient forms across the devloping blastula such that the concentration become too low to induce the expression of genes in cells distant from the uterine wall. One end becomes the head and so the developmental ontogeny unfolds. There is a reciprocal feedback between the environment, what genes are expressed and their timing of expression regulating the growth and development of an individual. Traits of organisms are inherited, but we also know that parts of their environment are inherited - such as a termite being born to a colony that was already built by the previous generation. These are known as legacy effects in niche constructionism. This is one of the ways in which natural selection acts on environments modified by the expression of genes in previous generations. This makes the environment a stable and heritable feature (or trait, or characteristic) of that population or species. This view has been called the macroevolution of ecosystem engineering.[21][22] Once again, genes don't just replicate around and create things - they interact. So is the basis of evolution really about "the passing of genes..."?
- Yes, it is. A genotype, whatever the range of environments, can only produce a constrained set of traits. This is why horses don't give birth to ants. Tim Vickers (talk) 05:58, 17 February 2010 (UTC)
- Are you certain horses don't give birth to ants? What an interesting idea! Traits are the variable bits. If genes produce traits then why would a cloned kitten express a different colored coat? This has been done. In identical twin studies there are many examples where separated twins express very different behavioural and phenotypic traits. If you work in a lab and code morphological character states, first you describe the homologous characters that define the groups under investigation and then you build your code book. For example, Tarsal organization (H, h), Carpus organization (I, i) , maxillary-prefrontal articulation (K, k', k). The homologous character (e.g., Tarsal organization) has several states (H = Ensatina and Plethodon have tarsal cartilages aranged as in all five toed members of the plethodon subfamily Desmognathinae and tribe Hemidactylini...h = In Aneides the fifth distal tarsal is relatively large...)[23] that describe the traits of the individual. Traits are character states. Genes code for homologous characters, traits are the variable bits. Genes do not produce traits, traits are an emergent property of gene and environment. Some traits might not even get expressed if the environmental conditions are altered.Thompsma (talk) 06:55, 17 February 2010 (UTC)
Individuals of a species mate, reproduce and exchange copies of genes among populations and from one generation to the next. Genes code for proteins that build cells, organs, bodies and other levels of biological organization in ways that are heritable. Traits are the heritable attributes that give each cell, organ, and a species its unique appearance, such as eye color, height or the colored pattern on a butterflies wing.
I realize that my suggestion in the previous quote is probably too wordy. However, I'm hoping that someone might pick up on what I'm trying to express here and see if we can word this better. Thanks.Thompsma (talk) 05:17, 17 February 2010 (UTC)
- True Thompsma environment plays a huge role in development ergo Evo-Devo was a logical consequence. The cloning of murine cancer cells to produce normal clones has always blown my mind from a developmental biologist viewpoint. But we have to distinquish phenotype in context of gene expression influenced by the environment and heritablity. Often these epigenetic factors are generally not heritable (granted some are and one can envision an environmental drive of epigenetic phentoypes that later gets "fixed" as a heritable genetic change or mutation) so heritability becomes a issue. I think you are correct we have to look at genes as gene networks rather than discrete units. Darwin's finches beaks associate with BMP and calmodulin alterations so we readily have an example of more than one gene, and a recent Science article implicate changes in regulatory elements of gene networks and evolution rather than mutations in protein sequence. GetAgrippa (talk) 14:31, 17 February 2010 (UTC)
- I really like Thompsma's idea to present "Traits" as emergent properties of gene networks and interaction with the environment. Further distinquish trait as biochemical, physiological, behavioral, morphological, .... GetAgrippa (talk) 15:56, 17 February 2010 (UTC)
- We could do that quite simply by saying "Genes produce an organism's inherited traits by interacting with the environment, with a trait being a particular characteristic such as eye color, height or the pattern on a butterflies wing." Tim Vickers (talk) 17:59, 18 February 2010 (UTC)
- It would be helpful to distinguish all the different kinds of traits - but I think this could go into the main body of the article. The lead will get too big - it is already fairly large. However, I hope that we are making headway - the comments seem to be more positive.Thompsma (talk) 06:18, 18 February 2010 (UTC)
Should we add genotype/phenotype distinction?:
Individuals of a species mate, reproduce and exchange copies of genes among populations and from one generation to the next. Genes code for proteins that build cells, organs, bodies and other levels of biological organization in ways that are heritable. Traits are the heritable attributes that give each cell, organ, and a species its unique appearance, such as eye color, height or the colored pattern on a butterflies wing. The genotype of an organism remains a stable part of an individuals life and development, whereas phenotypic traits, the behaviour or appearance of an individual, are responsive or malleable to different environmental circumstances. The range of phenotypic plasticity expressed across environmental gradients for any given species is known as the norm of reaction for a particular trait.
Thompsma (talk) 20:00, 17 February 2010 (UTC)
Took another look at this and was thinking that the lead could be shortened, but I think first we need to come to an agreement on what works. I think what the following sentence: "The basis of evolution is the passing of genes from one generation to the next." is trying to say, is that genes form lineages. Perhaps we could include this notion:
Evolutionary lineages are created as individuals within a species mate, reproduce and exchange copies of genes among populations and from one generation to the next. Genes code for proteins that build cells, organs, bodies and other levels of biological organization in ways that are heritable. Traits are the heritable attributes that give each cell, organ, and a species its unique appearance, such as eye color, height or the colored pattern on a butterflies wing. The genotype of an organism remains a stable part of an individuals life and development, whereas phenotypic traits, the behaviour or appearance of an individual, are responsive or malleable to different environmental circumstances. The range of phenotypic plasticity expressed across environmental gradients for any given species is known as the norm of reaction for a particular trait.
Thompsma (talk) 05:06, 18 February 2010 (UTC)
- That is much too complicated. If you are seriously considering putting concepts such as "norms of reaction" and "phenotypic plasticity" into the lead then you have failed to understand what a lead is for. A lead provides a simple introduction to an article by giving a basic outline of the important parts of a topic. We are not writing a review in Cladistics but an simple text that needs to be understood by high-school biology students. Tim Vickers (talk) 17:46, 18 February 2010 (UTC)
- True...but by this standard the current version doesn't achieve this either. In fact - it gives incorrect information to high school students about traits and how this really works. The concepts of traits, genotypes, and phenotypes are so muddled in this article that it would take a miracle for a beginner to walk away with a clear understanding of what is going on. The lead sentence:
"In biology, evolution is change in the inherited traits of a population of organisms through successive generations."
Inherited traits - right at the head - it is a little more complicated than you even thought according to the post earlier where I made clear the distinction between characters, states and their affiliated traits. Without repeating too much detail - traits are a product of gene/environment, which wasn't correctly understood. These sorts of details are important to know. Moreover, the information I have provided has nothing to do with cladistics - it is actually standard high school biology textbook stuff. Earlier, when I was referring to cladistics I was trying to explain the difference between anagenesis and cladogenesis - or microevolution and macroevolution. There has been a continued conceptual problem in this article that you can explain the speciation process through microevolution anagenesis without reference to population level phenomena on a population level scale - most evolutionists reject the micro-evolutoin explaining speciation phenomena. There was no conceptual way that someone could even start to grasp the concept of speciation by explaining only a microevolutionary vertical anagenic process without reference to the horizonal aspects evolution - i.e., populations being spatially and temporally sub-divided. This, however, is secondary to the topic at hand. As part of my current thesis in education I have been working with high school biology teachers on their curricula - so I know what is being taught in our province at least. I've had to have my own research studies in dealing with high school students approved by the board to fit into their accepted curricula. Here is an excerpt taken from the high school IRPs for our province[24]:
explain how the following principles are used in taxonomy to classify organisms: – evolutionary relationships – biochemical relationships – homologous structures – embryological relationships
There is more to the standards than this - you can read through the IRP yourself. I have also looked at the high school biology text and it has information on phenotypic plasticity and traits (properly described). Notice also that the concept of homology is introduced - which was earlier rejected as being too complex in this article - yet it is near universally accepted as one of the basic means of teaching on the concept of inheritance of traits. Hence, what is happening here is that the correct way of describing evolution is being rejected because it is too complex, whereas the simpler incorrect way of describing evolution is being accepted because it is easier to understand. The sentences are being crafted to match pre-conceived alternative conceptions that are unscientific and simply serve to reinfoce these views. I vote that we try to describe evolution in the correct manner, not in a simplistic misleading way. Perhaps we can find ways to tweak this paragraph to simplify the text even further - yet still maintain the correct meaning.Thompsma (talk) 18:25, 18 February 2010 (UTC)
- The point that genes interact with the environment to produce traits is covered in the article (Evolution#Heredity para 2), but if you want to put this in the lead it needs to be done simply. We could say Genes interact with the environment and this interaction produces an organism's traits, with a trait being a particular characteristic such as eye color or height. However, what we can't say is The range of phenotypic plasticity expressed across environmental gradients for any given species is known as the norm of reaction for a particular trait. This may have a pleasing level of technical accuracy, but an accurate but unintelligible introduction will fail in its primary function. Tim Vickers (talk) 18:46, 18 February 2010 (UTC)
- What I want is for it to be correct and simple. If this article is going to move away from the gene centered microevolutionary focus - which it must - it needs to describe what traits are. Your suggestion works - but I wonder if we could add that there are morphological, genetic and behavioural traits as was suggested by others posting in here? It is probably too much to get at all of these, but a simple modification might do the trick: Genes interact with the environment and this interaction produces an organism's traits, with a trait being a particular characteristic such as eye color, height, and certain behaviours. More complex traits describe things that are the product of several genes, such as the development of intricate patterns on a butterflies wing. I add the butterflies wing example because this gives a little more information on what a trait is - such as additive traits or pleiotropic effects. Once again - I'm not using the difficult terms - but I think it is fair game to open the readers mind a bit and to have them consider that there isn't a one-to-one relationship of gene to trait to phenotype.Thompsma (talk) 19:31, 18 February 2010 (UTC)
- As Einstein said "You explain things by making them as simple as possible, but no simpler"! That sounds a good compromise, since it is simple, but not too inaccurate. I'll slap it into the lead. Tim Vickers (talk) 19:48, 18 February 2010 (UTC)
Next paragraph in current lead
"Two main processes cause variants to become more common or rare in a population."
I think the first sentence can actually be removed. I went through the second paragraph and made some modifications. Posting it here for comment and feedback:
Natural selection is a process that acts on variable traits among individuals. Traits of individuals that are better suited to the environment help them survive, reproduce and pass their associated genes onto the next generation. Genes express traits with functional utilities, such as eyes that adapted for sight or wings adapted for flight. These adaptations evolve over many generations through successive, small, and random changes in the genes. Individuals with genes that express less favorable traits tend to perish. Only a certain number of individuals can survive within a population because environments have limited amounts of resources. These processes of natural selection alters the distributions of genetic lineages that are represented in subsequent generations and among populations. Not every trait, however, is adapted. Most genetic traits generated by random mutations are neither useful nor harmful, but instead they are completely neutral
andor nearly invisible to the process of natural selection. Neutral genes drift freely among populations and over consecutive generations. Genetic drift results from the role that chance plays in whether a given trait will be passed on as individuals survive and reproduce.
At first - I was critical of the final sentence. However, as I read over it again - I kinda like it and so I left it intact. This paragraph was modified because I don't feel as though the existing version defines what an adaptation is and it also misses the point about resource limits stemming population growth. If you don't succeed at first, try and try again.Thompsma (talk) 06:18, 18 February 2010 (UTC)
I also want to say that the version I present above is not in conflict with multi-level selection - it just avoids it for now. Actually - it avoids it explicitely. The first sentence uses the term individuals. Philosophers and evolutionists have been clear to point out that species are individuals, which is one of the foundations of multi-level selection.Thompsma (talk) 06:22, 18 February 2010 (UTC)
As an example of how to understand multi-level selection, here is how the preceeding could be re-written for species selection (I replace every instance of individual with species - and the same meaning is retained.):
Natural selection is a process that acts on variable traits among species. Traits of species that are better suited to the environment help them survive, reproduce and pass their associated genes onto the next generation. Genes express traits with functional utilities, such as eyes that adapted for sight or wings adapted for flight. These adaptations evolve over many generations through successive, small, and random changes in the genes. Species with genes that express less favorable traits tend to perish. Only a certain number of species can survive within a population because environments have limited amounts of resources. These processes of natural selection alters the distributions of genetic/species lineages that are represented in subsequent generations and among populations. Not every trait, however, is adapted. Most genetic traits generated by random mutations are neither useful nor harmful, but instead they are completely neutral and invisible to the process of natural selection. Neutral genes drift freely among populations and over consecutive generations. Genetic drift results from the role that chance plays in whether a given trait will be passed on as individuals survive and reproduce.
- This is why I still feel that the lead sentence to this article does not encompass the multi-level approach in its definition. It says:
"In biology, evolution is change in the inherited traits of a population of organisms through successive generations."
I think it might be better if it said (although this might be pulling hairs):
"In biology, evolution is change in the inherited traits of a population of individuals through successive generations."Thompsma (talk) 06:46, 18 February 2010 (UTC)
- Much inferior to the current version, poor grammar, confusing terminology and jargon in almost every sentence. You also seem to use a new definition of "population" - as a set of species (a definition that is non-standard in population genetics). Tim Vickers (talk) 17:55, 18 February 2010 (UTC)
- Once again - I don't think you are reading what I posted here. I never said that the second part was the proposal - I replaced individual with species for demonstration to show how the multi-level approach works. The upper quote box is the actual proposal. Moreover, the second paragraph isn't a new definition of a population - you can have a population of species - such as paleontologist use in their macroevolutionary studies. There are statistical populations - although I understand that it isn't the same kind of population and the concept is a little stretched in the demo paragraph - but that is why it was a demonstration. I'm getting frustrated at this again - these ideas are always being rejected - yet it is clear that until a few days ago you didn't even understand what a trait is. I'm not trying to be offensive - but it is a difficult to accept that I'm using too much jargon as a critique from someone who has a hard time with the fundamentals. Rather than being obstinate and rejecting things outright - why don't you be constructive and work with me in here. The current lead is wrong - so how could anything otherwise be inferior?!! It is only inferior to the current version because it doesn't conform to your alternative conception[25] - which is microevolutionary reductionism and doesn't explain speciation. I do studies on alternative conceptions in high school students where we have done concept inventories on evolution and ecology. You are fitting into one of the classical dilemmas we see in students notions of speciation. Here are a few papers on concept inventories and concept maps in relation to biology and evolution: [26][27]. These papers also introduce some of the introductory terms that are used at this level of education. You are arguing an alternative conception of evolution that does not fit with the published understanding.Thompsma (talk) 18:44, 18 February 2010 (UTC)
- Again, you are personalizing a discussion, please do not do that. Your idea to explain why selection occurs is good, but this can be expressed much more simply. Tim Vickers (talk) 19:35, 18 February 2010 (UTC)
- As a courtesy - posting an alternative is helpful - or actually pinpointing the grammatical mistakes is also helpful - but to reject proposals outright without following up on an explanation can be taken as offensive and is a source of frustration. Your follow-up proposal is much better.Thompsma (talk) 19:44, 18 February 2010 (UTC)
- Sorry, I'll explain on your talkpage why I'm feeling a bit frazzled at the moment. Tim Vickers (talk) 19:52, 18 February 2010 (UTC)
Two main processes cause variants to become more common or rare in a population. One is natural selection, which causes traits that aid survival and reproduction to become more common, and traits that hinder survival and reproduction to become more rare. Natural selection occurs because only a few individuals in each generation will survive, since resources are limited and organisms produce many more offspring than their environment can support. Over many generations mutations produce successive, small, random changes in traits, which are then filtered by natural selection and the beneficial changes retained. This adjusts traits so they become suited to an organism's environment: these adjustments are called adaptations. Not every trait, however, is an adaptation. Another cause of evolution is genetic drift, an independent process that produces entirely random changes in how common traits are in a population. Genetic drift comes from the role that chance plays in whether a trait will be passed on to the next generation.
ETYMOLOGY!
etymology How and who made it come about. Faro0485 (talk) 18:34, 17 February 2010 (UTC)
- Then again, Wikipedia is not a dictionary. Gabbe (talk) 18:40, 17 February 2010 (UTC)
- If you really want to know...before Darwin's concept of evolution came about, evolution meant literally the unfolding. The prevailing idea before Darwin and during his grandfathers time, who also wrote about the evolution of traits and common descent, was that there was a homunculus unfolding. The homunculus was the idea that the sperm contained a little being in it that would unfold after birth. This was called evolution. Darwin's grandfather, Erasmus Darwin, rejected this:
When the crude embryo careful Nature breeds,
See how she works, and how her work proceeds, While through the mass her energy she darts, To free and swell the complicated parts, Which only does unravel and untwist,
Th'invelop'd limbs, that previous there exist.
"Many ingenious philosophers have found so great difficulty in conceiving the manner of the reproduction of animals, that they have supposed all the numerous progeny to have existed in miniature in the animal originally created; and that these infinitely minute forms are only evolved or distended, as the embryon increases in the womb."
"Perhaps all the productions of nature are in their progress to greater perfection? an idea countenanced by the modern discoveries and deductions concerning the progressive formation of the solid parts of the terraqueous globe, and consanant to the Creater of all things...the world itself might have been generated, rather than created; that is, it might have been gradually produced from very small beginnings, increasing by the activity of its inherent principles, rather than by a sudden evolution of the whole by the Almighty fiat. --What a magnificient idea of the infinite power of THE GREAT ARCHITECT! THE CAUSE OF CAUSES! PARENT OF PARENTS! ENS ENTIUM!...Thus it would appear, that all nature exists in a state of perpetual improvement by laws impressed on the atoms of matter by the great CAUSE OF CAUSES; and the world may still be in its infancy, and continue to improve FOR EVER AND EVER. But it may appear too bold in the present state of our knowledge on this subject, to suppose that all vegetables and animals now existing were originally derived from the smallest microscopic ones, formed by spontaneous vitality? and that they have, gradually acquired the size, strength, and excellence of form and faculties, which they now possess? and that such amazing powers were originally impressed on matter and spirit by the great Parent of Parents! Cause of Causes! Ens Entium!"
The precending quotes actually came from a collection of Erasmus Darwin's papers. His historical works are an impressive read!! My favorite is his word: terraqueous globe!Thompsma (talk) 20:26, 17 February 2010 (UTC)
- The etymonline source is generally ok, and the claim that "evolution" then referred to embryological development is supported by Costa's notes to the Origin. Not sure that the "homunculus" was the prevailing view, seem to recall it being strongly contested by Erasmus's time but no source to hand. An obvious point about the etymonline description, it's wrong to imply regarding "evolution" that "Charles Darwin used the word only once, in the closing paragraph of "The Origin of Species" (1859)" since CD used "evolved" in that one instance. . . . dave souza, talk 18:19, 18 February 2010 (UTC)
- If you read what I posted - I quoted Erasmus Darwin directly where he says he rejected the homunculus concept:
"Many ingenious (i.e., incorrect) philosophers have found so great difficulty in conceiving the manner of the reproduction of animals, that they have supposed all the numerous progeny to have existed in miniature (i.e., homunculus) in the animal originally created; and that these infinitely minute forms are only evolved or distended, as the embryon increases in the womb."
- Prior to 1800 - homunculus unfolding was evolution, although Erasmus' ideas on this were considered speculative and so even he hadn't changed this established notion at this time. The homunculus remained probably until Weisman's germ plasm theory came about in the late to mid-1800's.Thompsma (talk) 18:30, 18 February 2010 (UTC)
- Got a source for that? On the overview, transmutation of species equated to our idea of evolution, alternatively the "development hypothesis" as in Vestiges of Creation. Spencer is credited with popularising the term "evolution" in its modern meaning.[28] . . . dave souza, talk 19:03, 18 February 2010 (UTC)
- Sure - this came from a couple published sources: [29], [30], [31] —Preceding unsigned comment added by Thompsma (talk • contribs)
- Thanks, unfortunately as an amateur I don't have access to these journals. Will try to watch out for info on the development of ideas of embryology. As for the term "evolution" in its modern use, Adrian Desmond in The Politics of Evolution (ISBN:0226-14374-0) p. 5 quotes usage in the Edinburgh New Philosophical Journal 1826, "Observations on the Nature and Importance of Geology". He attributes it to Robert Edmond Grant, but I recall this being disputed, and it may have been by Jameson. That predates Lyell's use of the term in 1832 when attacking Lamarck's ideas. More on this if we want to get into use of the term, may be useful in the "history" article. . . dave souza, talk 20:42, 18 February 2010 (UTC)
- The 1826 use describes Lamarck's belief about worms and infusoria that "all other animals, by the operation of external circumstances, are evolved from these in a double series, and in a gradual manner." Desmond 1989 (paperback 1992) says Grant wrote that, as above, but Desmond and Moore's Darwin of 1991 (paperback 1992) page 40 attributes it to Robert Jameson, and Browne's Charles Darwin: Voyaging of 1995 page 81 suggests it was Grant, but says the authorship is still hotly debated. . . dave souza, talk 23:57, 18 February 2010 (UTC)
- Thanks, unfortunately as an amateur I don't have access to these journals. Will try to watch out for info on the development of ideas of embryology. As for the term "evolution" in its modern use, Adrian Desmond in The Politics of Evolution (ISBN:0226-14374-0) p. 5 quotes usage in the Edinburgh New Philosophical Journal 1826, "Observations on the Nature and Importance of Geology". He attributes it to Robert Edmond Grant, but I recall this being disputed, and it may have been by Jameson. That predates Lyell's use of the term in 1832 when attacking Lamarck's ideas. More on this if we want to get into use of the term, may be useful in the "history" article. . . dave souza, talk 20:42, 18 February 2010 (UTC)
- Sure - this came from a couple published sources: [29], [30], [31] —Preceding unsigned comment added by Thompsma (talk • contribs)
- I realized people might have trouble accessing the lit - this is why I quoted Erasmus directly. You can see that he saw it as an unfolding in its historical meaning of the term. You can access the OED[32] for the etymology of the term. The Erasmus quotes puts the term into context of its historical meaning: "The process of unrolling, opening out, or revealing (see OED)" compared to the modern use of the term. Reading through the OED, the modern meaning may stem from Charles Lyell: "1832 C. LYELL Princ. Geol. (ed. 2) II. 11 The testacea of the ocean existed first, until some of them by gradual evolution, were improved into those inhabiting the land." Charles Darwin only used the term in the last sentence of the first edition of the origin:
- "There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved."
- He used it more frequently in subsequent editions, but he never used the whole term evolution - he just said evolved.Thompsma (talk) 22:04, 18 February 2010 (UTC)
- Sorry that I was unclear, agree that evolution meant unrolling and it's clear that it was associated with embryos unrolling, but I had the impression that the homunculus idea was disputed and discarded rather earlier. . dave souza, talk 23:57, 18 February 2010 (UTC)
- Lyell does seem to be the first using "evolution", preceded by Grant or Jameson using "evolved" as discussed above. A minor clarification, Darwin used the term "evolution" itself in Variation of 1868, page 60, conjecturing that "a vast number of characters, capable of evolution, lie hidden in every organic being." He used the term numerous times in Descent in 1871, first on page 2, similarly in the 1872 Expression of the Emotions,[33] and a few times in the 1872 6th edition of The Origin, including mention of "the theory of evolution through natural selection".[34] . . dave souza, talk 23:57, 18 February 2010 (UTC)
- Thanks souza - good to know - my source was unreliable. As with all scientific ideas - there are always lingering perspectives - the homunculus might have been formally rejected prior to 1800 - but as Erasmus' notes illustrate and I've also seen this in other writings of this time - there were a few people who held onto that notion.Thompsma (talk) 00:03, 19 February 2010 (UTC)
- Thanks, there are many minor myths about Darwin and Darwin Online is invaluable for checking. Very interesting about the homunculus, there does seem to have been a wide spread of ideas at that time. . . dave souza, talk 00:38, 19 February 2010 (UTC)
- Thanks souza - good to know - my source was unreliable. As with all scientific ideas - there are always lingering perspectives - the homunculus might have been formally rejected prior to 1800 - but as Erasmus' notes illustrate and I've also seen this in other writings of this time - there were a few people who held onto that notion.Thompsma (talk) 00:03, 19 February 2010 (UTC)
- He used it more frequently in subsequent editions, but he never used the whole term evolution - he just said evolved.Thompsma (talk) 22:04, 18 February 2010 (UTC)
Great lead - Hopeful monsters
Just wanted to say that it has been a tough go - but I think the lead to this article has seen much improvement. I think it is a good lead. Thought I would also add that there is a recent article in the latest issue of nature[35] that puts an interesting twist into the puzzle - it talks about studies suggesting that Richard Goldschmidt's hopeful monsters theory is back!! Regular macromutations of significant adaptive value are seen in sticklebacks showing recurrent evolution in their body armor. This was also seen in an erlenmeyer flask experiment after 33,127 generations one population of Escherichia coli exploited a new biochemical pathway becoming Escherichia erlenmeyeri; I should qualify that E. erlenmeyeri is not a real biological species - more like Homo economicus. The research is still young, but there are interesting developments to follow.Thompsma (talk) 05:46, 19 February 2010 (UTC)
- Yes, I read that yesterday, but I note that they were careful to state that the regulatory mutation didn't explain all of the spine length. We do have an article on the E. coli long-term evolution experiment, and they even gave us a photo for it! Tim Vickers (talk) 17:45, 19 February 2010 (UTC)
Two small questions about the second paragraph:
The basis of evolution is the passing of genes from one generation to the next. Genes interact with the environment and this interaction produces an organism's traits; with a trait being a particular characteristic such as eye color, height, and some behaviors. More complex traits, such as the intricate patterns on a butterflies wing, are influenced by several genes. Genes vary within populations, so organisms show heritable differences (variation) in their traits. Evolution is the product of two opposing forces: processes that constantly introduce variation in traits, and processes that make particular variants become more common or rare. The main processes producing variation are mutations in genes, or the transfer of genes between populations and between species. New combinations of existing genes are also produced by genetic recombination.
- What type of behaviour could not be labeled as a characteristic - i.e., some but not others? As I think this over - I'm fairly certain that all behaviours can be classed as traits. Some behaviour is learned, others instinctual, but even the learned behaviour becomes a trait.
- I can definitely see your argument, genes build brain, brain interacts with environment, behaviors emerge. Instincts and reflexes are unarguably traits, but I've hung around with enough philosophers to think that the idea that behaviors such as "poetry" are traits might be controversial! What about saying "or a behavior", which avoids the issue entirely? Tim Vickers (talk) 17:43, 19 February 2010 (UTC)
- The third sentence is a little out of place - it doesn't flow well into the next sentence. The fourth sentence seems more like the topic of this paragraph:
Evolution is the product of two opposing forces: processes that constantly introduce variation in traits, and processes that make particular variants become more common or rare. The main processes producing variation are mutations in genes, or the transfer of genes between populations and between species. New combinations of existing genes are also produced by genetic recombination. The basis of evolution is the passing of variable sets of genes from one generation to the next. Genes interact with the environment and this interaction produces an organism's traits; with a trait being a particular characteristic such as eye color, height, and different behaviors. More complex traits, such as the intricate patterns on a butterflies wing, are influenced by several genes. Genes vary within populations, so organisms show heritable differences (variation) in their traits.
Thompsma (talk) 16:51, 19 February 2010 (UTC)
- Well there we say "variation comes from genes" and only then "the basis of evolution is genes", we need to say that genes are important before we explain why. You're right that the "basis of evolution" sentence leads much better from the first paragraph though. Tim Vickers (talk) 18:08, 19 February 2010 (UTC)
Evolution is the product of two opposing forces: processes that constantly introduce variation in traits, and processes that make particular variants become more common or rare. Traits are a particular characteristic such as eye color, height, or a behavior, and are produced when an organism's genes interact with its environment. Genes vary within populations, so organisms show heritable differences (variation) in their traits. The main processes producing variation are mutations in genes, or the transfer of genes between populations and between species. New combinations of existing genes are also produced by genetic recombination. Evolution occurs as organisms pass these variable sets of genes from one generation to the next.
Yes...this reads better, but could produced be replaced with expressed: "...and are produced expressed when an organism's genes interact with its environment."? A strong argument can be made that human cultural and social intelligence are traits. Psychologists often refer to human personality traits (e.g., [36], [37], [38]). Hence, all behaviour is subsumed under this usage. However, your rephrasing solves this problem anyway.Thompsma (talk) 20:23, 19 February 2010 (UTC)
- Good idea, new version now live! Tim Vickers (talk) 20:47, 19 February 2010 (UTC)
Kudos
Wow!!! Kudos to the monumental effort to improve the lead-much better. Concise but not too technical or wordy for the novice. Really impressed and proud of you guys (and gals if appropriate). Some of the best discussions in years too-and civil too. Keep up the momentum. Regards, GetAgrippa (talk) 16:04, 19 February 2010 (UTC)
- It is Kung fu, "human accomplishment arrived at by great effort". Tim Vickers (talk) 17:49, 19 February 2010 (UTC)
- Agree. Well disposed and highly informed contributors can and do make the difference here in Wikipedia. And now the customary nitpicking suggestion from a lesser informed editor. The sentence in the 1st paragraph "These smaller populations become separate species when they can no longer breed with each other." could be extended to say "and thus become genetically isolated from one another" or "breed and exchange genetic material with each other" or something to that effect. Just nitpicking.--LexCorp (talk) 17:54, 19 February 2010 (UTC)
- Well we haven't yet introduced the idea of genes at that point, but we might be able to deal with this later on in the introduction. Tim Vickers (talk) 18:10, 19 February 2010 (UTC)
- I see what you mean. Much better to modify the 1st sentence of the 2nd paragraph to reflect that this is what happens during reproduction/breeding. Another nitpicking suggestion is to include "history" in the sentence "providing a unifying explanation for the diversity of life on Earth." in the 3rd paragraph thus "providing a unifying explanation for the history and diversity of life on Earth.".--LexCorp (talk) 18:25, 19 February 2010 (UTC)
- Good, thanks. Added. Tim Vickers (talk) 19:09, 19 February 2010 (UTC)
- I see what you mean. Much better to modify the 1st sentence of the 2nd paragraph to reflect that this is what happens during reproduction/breeding. Another nitpicking suggestion is to include "history" in the sentence "providing a unifying explanation for the diversity of life on Earth." in the 3rd paragraph thus "providing a unifying explanation for the history and diversity of life on Earth.".--LexCorp (talk) 18:25, 19 February 2010 (UTC)
- Well we haven't yet introduced the idea of genes at that point, but we might be able to deal with this later on in the introduction. Tim Vickers (talk) 18:10, 19 February 2010 (UTC)
- Agree. Well disposed and highly informed contributors can and do make the difference here in Wikipedia. And now the customary nitpicking suggestion from a lesser informed editor. The sentence in the 1st paragraph "These smaller populations become separate species when they can no longer breed with each other." could be extended to say "and thus become genetically isolated from one another" or "breed and exchange genetic material with each other" or something to that effect. Just nitpicking.--LexCorp (talk) 17:54, 19 February 2010 (UTC)
Latest research on Evolution
I think there is a need to add a new section in this article which encompasses what the latest research has proved about evolution. After reading the article, I am still confused about which theory is the closest to explaining Evolution. Theories get obsoleted and redefined with each new discovery. I strongly emphasize the need for the new section at the end. "" (talk) 11:25, 20 February 2010 (UTC)
- You are absolutely right. Updating the article is being discussed on this talk page. Feel invited. --Fama Clamosa (talk) 12:59, 20 February 2010 (UTC)
Good English?
My English has never been great so I'm sorry if I'm on the wrong track here, but this sentence doesn't make sense to me:
- As they evolve populations diverge from one another and may become new species.
We're referring to populations, plural, and then saying they diverge. If we're talking about (at least) two distinct populations mustn't they have already diverged? Another intended meaning I can see here is that all populations diverge, but then that wouldn't be true (a population may become extinct for instance). The last intended meaning I see, and the one I think this sentence is going for, is the following:
- As a population evolves it may diverge and the resulting populations may become new species.
Or something along those lines? Cheers, Ben (talk) 13:33, 20 February 2010 (UTC)
Not necessarily, since geographic separation does not imply Genetic divergence. Anyhow, I took a stab at improving it. Mildly MadTC 17:16, 20 February 2010 (UTC)
Lead sentence
Genetic reductionism has crept back into the lead sentence! I went back and replaced it with a previous version that we had agreed upon by focusing on traits. The Douglas Futuyama textbook does give the reductionist genetic view, but he has been criticized for this in the peer-reviewed literature. This article should be NPOV and cover a more inclusive definition. What is currently posted may not suffice, but it is better than the previous. Here is a more inclusive description taken from Strickberger's Evolution, Fourth Edition (2008)[39]:
Although some thought otherwise, population genetics does not provide a complete theory of evolution. Now evolution is seen as hierarchical, operating on organisms on at least three levels:
- the genetic level, seen as substitution of alleles, changes in gene regulation and changes in gene networks;
- the organismal level, seen as individual variation and differential survival through adaptation and the evolution of new structures, functions and/or behaviors; and
- changes in populations of organisms, seen as the curtailment of gene flow between populations and the subsequent origin, radiation and adaptation of species (see Box 11-1, Hierarchy).
Natural selection acts because of the differential survival of individual organisms with particular features. The response to selection lies in the information content of the genome, information that can change because of mutation. Because evolution acts at genetic, organismal and population
levels, a definition ideally should reflect evolution at all three levels. In many respects, Darwin’s concept of descent with modification remains an inclusive definition of (biological) evolution. Evolution is descent with modification, encompassing evolutionary change at genetic, organismal and/or population levels.
The hierarchical view of evolution is more generally applied in the literature. The genetic reductionist stance is adhered to by only a few and it ignores the majority of other researchers that say evolution is more than this. The current lead sentence moves away from genetic reductionism by incorporating traits into definition:
In biology, evolution is change in the inherited traits of a population of organisms through successive generations.
This is more hierarchical. If people have suggestions for a revision to improve the sentence, please offer your suggestions. The quote from Strickberger's Evolution might help to find a common ground because the narrow view of evolution as only genetic changes does not serve the purposes of this article.Thompsma (talk) 17:21, 2 March 2010 (UTC)
computer science addition
{{editsemiprotected}} Please add computer science in the list of fields where evolution is applied and studied.
--Infiniter (talk) 19:13, 9 March 2010 (UTC)
- Please provide an appropriate reference to a reliable source, and reinstate this request (perhaps a book that covers the topic; please give details - ISBN, date, publisher, etc). Thanks. Chzz ► 19:21, 9 March 2010 (UTC)
Not done
Cultural evolution
Although challenging, this article should include a section on cultural evolution. I notice that there is a wiki article on Sociocultural evolution - which might be a better title, but I'm more familiar with it being addressed more simply as cultural evolution. There are some recent and old articles on this subject area that could be synthesized into a paragraph or two to summarizes the issues. The section on 'Social and cultural responses' does not discuss any of the research done on linguistic studies, for example. The following paper[40] includes a fairly recent summary on cultural evolution - there are many others. There has also been lots of publications on the phylogenetics of linguistic data - such as the work of Luigi Luca Cavalli-Sforza (e.g. [41]).Thompsma (talk) 23:33, 25 February 2010 (UTC)
- But surely this article is about biological evolution.--62.249.233.80 (talk) 17:26, 2 March 2010 (UTC)
- Agreed. This article should not be confused by the addition of cultural evolution. It is unnecessary and would merely add another type of dispute to this article. If it's not already in the "see also" section, perhaps Sociocultural evolution could be added there. --PLUMBAGO 17:33, 2 March 2010 (UTC)
- So cultural evolution is not part of biological evolution? Why would the topic appear in the journal of evolution - Alex Mesoudi, Andrew Whiten and Kevin N. Laland (2004). Is Human Cultural Evolution Darwinian? Evidence Reviewed from the Perspective of "The Origin of Species". Evolution, 58(1), 1-11?? The idea that we are not biological beings can be rejected outright. Cultural evolution is part of evolution and just because people are a little concerned about a dispute is certainly no reason to back away. There is no excuse for censorship blocking these important ideas from being included. It is entirely consistent with the topic and is used extensively in psychology, anthropology and linguistics. There are articles in both Nature and Science that address this aspect to evolution. To block this from inclusion means that only part of the story is being told. Let's tell the whole story. I'm reading through the material as part of a graduate class I'm taking in evolutionary psychology and will prepare a paragraph and will post it here for discussion in a few weeks.Thompsma (talk) 18:11, 2 March 2010 (UTC)
- It is not that the matter is controversial, it is that much of the research is fringe - a lot of evolutionary psychology is really biological reductionism that has little to do with Darwin's understanding of natural selection. No one doubts that humans are biological, and there is a fair amount of research - good scientific research - on how culture evolved (see terrence Deacon's work, for example). But culture in this sense is by definition all those extrasomatic aspects of human life. It is in this sense that culture is the sphere of anthropology. Now, what anthropologists mean by cultural evolution is a complex topic and there is plenty of controversy, but it is as related to this article as the article on stellar evolution (you do agree by the way that all of us are made out of stardust, right? That's basic physics)> Slrubenstein | Talk 18:20, 2 March 2010 (UTC)
- No, cultural evolution is not part of biological evolution. Darwinian processes act on other things besides biology. Humans are biological, and our culture ultimately derives from our brains, but cultural evolution is not itself biological. thx1138 (talk) 18:50, 2 March 2010 (UTC)
- Precisely. This is the point. No serious scholar, as far as I know, is claiming that cultural evolution is part of biological evolution. The claim is that the mechanisms of cultural evolution are the same as those of biological evolution—that they are two expressions if the same evolutionary processes. Now, as I say, this is hotly debated, but that doesn't in itself mean it should be excluded from this article. A lot of well respected thinkers, like the writers of the article mentioned, like Susan Blackmore, like Dan Dennett, hold views along these lines. My view is that, currently, "evolution" means "biological evolution" to most people in academia as well as outside it, so this article probably shouldn't discuss cultural evolution in detail. However, I think it should mention it briefly, and redirect to a fuller article. And I can certainly imagine a future where this article should be changed to be about evolutionary processes in general, with a link to a separate article on biological evolution. garik (talk) 19:17, 2 March 2010 (UTC)
- It's worth adding that people may be getting their wires crossed here: it's important to distinguish between the (non-biological) evolution of culture (i.e. something that happens to culture once it has come into existence) and the biological evolution that is necessary for culture to exist at all. Culture in this context should also be understood as referring simply to that part of human behaviour that is transmitted through learning rather than through genes. The term "cultural evolution" was used historically to refer to ideas of cultural progression, which led to some peoples being considered more primitive than others. That's not what people mean by the term nowadays, and it's certainly not what anyone means here, as far as I can see. garik (talk) 19:24, 2 March 2010 (UTC)
- Precisely. This is the point. No serious scholar, as far as I know, is claiming that cultural evolution is part of biological evolution. The claim is that the mechanisms of cultural evolution are the same as those of biological evolution—that they are two expressions if the same evolutionary processes. Now, as I say, this is hotly debated, but that doesn't in itself mean it should be excluded from this article. A lot of well respected thinkers, like the writers of the article mentioned, like Susan Blackmore, like Dan Dennett, hold views along these lines. My view is that, currently, "evolution" means "biological evolution" to most people in academia as well as outside it, so this article probably shouldn't discuss cultural evolution in detail. However, I think it should mention it briefly, and redirect to a fuller article. And I can certainly imagine a future where this article should be changed to be about evolutionary processes in general, with a link to a separate article on biological evolution. garik (talk) 19:17, 2 March 2010 (UTC)
- No, cultural evolution is not part of biological evolution. Darwinian processes act on other things besides biology. Humans are biological, and our culture ultimately derives from our brains, but cultural evolution is not itself biological. thx1138 (talk) 18:50, 2 March 2010 (UTC)
- Sorry, but the viewpoint that cultural evolution is not biological is '100% incorrect. It is entirely part of biological evolution. From the fixed action potential of neurons, to the network of brain development and onto imagination in our prefrontal cortex - behaviours and culture expressions are biological in nature. If you don't believe me, then read some of the literature on cognitive neuropsychology[42]:
Before delving deeply into the argument, we should discuss a major finding in neuroscience that we will be assuming throughout: Imagining and doing use a shared neural substrate.
The argument that cultural evolution is not biological can only stem from a misunderstanding of how behaviour works. The topic has been discussed at great length in many publications from the primary literature looking at questions pertaining to culture in chimp troops[43] and orangatans[44], for example.
In the biological sciences, a more inclusive definition is accepted, in which the significance of cultural transmission is recognized as one of only two important processes that can generate evolutionary change: inter-generation transmission of behaviour may occur either genetically or through social learning, with processes of variation and selection shaping biological evolution in the first case and cultural evolution in the second.
[45] (Emphasis added)
It is not fringe research either - it is part of peer-reviewed science and an active field of discovery. Could you imagine if the authors of the quoted paper above had submitting their paper on cultural evolution to Nature and titling it 'The fringe science of cultural evolution in chimpanzees!?' - it does not work this way. You are equating cultural evolution with human evolution only. I'm teaching first year biology at our university and in the Campbell textbook on biology (one of the most common textbooks used in introductory biology) cultural evolution is included as part of the lessons. Many of the questions in chapter 51 on animal behaviour, for example, are centered on the evolution of culture. You cannot tell me that it is not biological, nor can you convince me that it is fringe science. Cultural evolution is biological and the ideas and misinformation being presented in here tells me that a proper introduction to the subject is badly needed. Thompsma (talk) 19:19, 2 March 2010 (UTC)
- It might be argued that we have cultural versus biological evolution - but this is semantics. In reality you cannot tease the two apart. It is similar to peoples concept of nature - some think that nature only exists in places where people never existed, whereas some think nature is sitting right out on their front lawn or even at the end of their nose where bacteria and nematodes flourish. Cultural evolution is biological, but it is also true that what is being transmitted are not DNA molecules. Still - physical transmission does occur - either sound waves, or light or some other mode of communication. It is still biologically tied to a central nervous system and reciprocally feeds back into the evolution of both.Thompsma (talk) 19:26, 2 March 2010 (UTC)
- Well, I believe this is a distinction that, for example, Alex Mesoudi, Andy Whiten, and Kevin Laland would most definitely make: cultural evolution in this context is about evolutionary processes working on culture directly, without any change in gene frequencies among the relevant organisms at all. garik (talk) 19:29, 2 March 2010 (UTC)
- No one's claiming that culture isn't underpinned by biology. To have culture, for example, you almost certainly need a brain (among other things), and a brain is clearly a biological thing. garik (talk) 19:30, 2 March 2010 (UTC)
- Well, I believe this is a distinction that, for example, Alex Mesoudi, Andy Whiten, and Kevin Laland would most definitely make: cultural evolution in this context is about evolutionary processes working on culture directly, without any change in gene frequencies among the relevant organisms at all. garik (talk) 19:29, 2 March 2010 (UTC)
- No one is claiming that humans did not evolve, and what distinguishes humans is cultue, so culture is indeed the product of our biological evolution. But that does not make it reducible to biology. This is painfully obvious. An example of ecultural evolution is the transformation of Latin into Portuguese, Spanish, Catalan, French, Italian, Romanian, etc. Anthropologists, and more specifically historical linguists, study the forces at work in this example of cultural evolution. But the causes for these changes - and the evolution of French and Spanish out of Latin is as much a matter of a change in phonemes and morphemes as much as the evolution of humans and chimps from some prior primate species is a matter of a change in gene alleles and gene frequencies. Indeed, both may be subject to naturoa (i.e. environmental) selection and in this sense Darwin is useful. But no one thinks that the reason the French speak French and Spaniards speak Spanish is because of biological differences. No one believes that French and Spanish evolved out of latin because of some change in human biology. This is an idea so clearly absurd it doesn't warrant any further discussion. Slrubenstein | Talk 19:46, 2 March 2010 (UTC)
- However, it is also true that not every inflection and subtle tonation of different languages can be learned after a critical developmental period (e.g., [46]); I just quickly found that reference, but I can find others that support this. Once structured into our linguistic repertoire there are developmental factors that lock in. Moreover, as demonstrated by Noam Chomsky back in the 50's and 60's - there is a genetic basis to the grammatical structuring of language. Furthermore, the concept that culture has not had an impact on our genetic development is not supported by the evidence at hand. Culture has shaped our genetics. Here is what Laland and other have suggested:
Researchers from diverse backgrounds are converging on the view that human evolution has been shaped by gene–culture interactions.
- There are many other publications linking the reciprocal feedback between genetics and culture.Thompsma (talk) 20:12, 2 March 2010 (UTC)
None of the above supports your premise. Yes, language is biologically based, but language evolution is not. This article is about evolution in biology. If we mention cultural evolution it should be on the disambiguation page. thx1138 (talk) 20:15, 2 March 2010 (UTC)
This article reviews more than one hundred genetic studies of language. The results of these studies strongly suggests that genetic factors play a role in the variation in the rate of language acquisition and linguistic proficiency attained by children and adults. Genetic factors account for much of the variance in linguistic abilities among people with written or spoken language disorders and some of the variance in linguistic abilities among normal people.
(from: Stromswold, K. (2001). The Heritability of Language: A Review and Metaanalysis of Twin, Adoption, and Linkage Studies. Language, 77(4), 647-723)
What determines the historical evolution of any particular language across the possibility space formed by these different options? In this issue of PNAS, Dediu and Ladd (1) present evidence suggestive of an answer that has seldom been considered before, which is that interpopulation genetic differences may play a role.
[52]Thompsma (talk) 20:26, 2 March 2010 (UTC)
- The first quote doesn't support your claim at all. The second sort of does, but it is by no means definitive. Art can be said to evolve, too, but it is not biological evolution. thx1138 (talk) 20:34, 2 March 2010 (UTC)
- Of course there are going to be little disagreements here and there over cultural evolution and how much a part genes vs. environment has a role to play. The reality is that culture cannot exist without biological agents - I see the two as being one in the same, others deem it necessary to separate them out. I could make a cogent argument that art does evolve by means of biological evolution, but I'm not going to do this. The original proposal was that there should be one paragraph included in here that describes the basics of cultural evolution with a link to the sub-article dealing with it in more detail. I still stand by this and think it should be included. Others in here seem to agree with this notion. We can keep it simple and restrict it to one paragraph to avoid extensive debate.Thompsma (talk) 20:52, 2 March 2010 (UTC)
- "Moreover, as demonstrated by Noam Chomsky back in the 50's and 60's - there is a genetic basis to the grammatical structuring of language." Chomsky never proved that, and I would say Deacon's argument against and alternative are very persuasive. As to human culure having influenced biological evolution sure, sickele-cell anemia is an example, this is just Baldwinian evolution, it id old hat and can be discussed perhaps in the human evolution afrticle. Likewise one could quote Geertz' famous article on "Man makes himself" from his 1973 book on the role of cultureal feedack in the evolution of the human brain, this stuff is utterly uncontroversial. But let us stuck to the point. Biology still doesn't explain the evolution of culture. It odoes not explain the evolution of language (I guess you just gave in to my example above) and it certainly does not explain the evolution of say cubism in at. Up to a certain point, one can use paleolithic art as both an index for human evolution and as a formtive factor in human evolution, but as I and others have pointed out, you have to destinguish between the evolution of modern humans with a universal capacity for culture, versus the changes in cultures since then. Slrubenstein | Talk 21:40, 2 March 2010 (UTC)
- Thompsma, you seem to be misunderstanding what's meant by cultural evolution. No one is claiming that the foundations of culture are not biological. Of course they are! The claim is that there are two kinds of evolution at work here. In biological evolution, gene frequencies change over time. In cultural evolution the frequency of cultural variants (e.g. the particular phonetic patterns used to mean "fish", to take an example at random) changes over time. The key issue is that, while culture depends on biological mechanisms (and while, say, language may indeed have a specific genetic basis to some extent), much cultural variation cannot be explained on the basis of variation in gene frequencies. I say "fish", my French friends say "poisson". That variation is the result of cultural, not biological, evolution, even if the fact that we use language at all owes much to biology. garik (talk) 22:03, 2 March 2010 (UTC)
- I'm not misunderstanding, confused, nor do I need a cultural evolution 101 - I have a full comprehension and I have studied in this area for many years. It is about an understanding of the language through metaphor. Is it biological or cultural - it depends on your cognitive interpretation. Get a group of people to draw a concept map on what is natural or biological and you will find that people have different ideas of what this means. Is oxygen biological? What about carbon, hydrogen and so on? These are elements that exist outside of biological beings - and not until they are organized as biomolecules do we say that they are part of the biological structure. The same can be said of the building blocks in culture. It is a philosophical argument and one that can made in either way. Of course I understand the way that you are presenting it - genes versus learned transmission. The argument was presented earlier on that this article is only about biological evolution. Cultural evolution is biological in the sense that it is only biological beings that can express culture. Moreover, the way that our somatosensory systems relate to behaviour (fixed-action, social-cultural) has biological foundations that feed-back into our cultural expressions. There are neural substrates that light up on fMRI scans when we study cultural traits - culture doesn't run on its own. Communication relates to our anatomy of our larynx, ears and so on - there is a biological basis behind all things cultural. There are different modes of evolution in the two - I am not disputing this, but to say that one is biological and the other is not - does not make sense to me. You cannot tease the two apart - they are integrated and whole. This is also reflected in the multi-level hierarchical view of evolution - there are emergent phenomena that are subject to the forces of natural selection above the gene. Do we start saying that species selection isn't biological? What about the evolution of the environment as proposed by Odling-Smee and Laland in their niche construction hypothesis? Is the termite mound biological or non-biological? According to the niche constructionists - the mound itself is subject to the forces of natural selection - with legacy effects, one generation inherits the home built by the previous generation. Hence, there is an expanded viewpoint and argument that can be made here that makes it very difficult to separate cultural evolution from its biological aspects. Culture is integrated into the evolution of biological systems - so it should be discussed along side it as well. I'm in a rush here - got to run. I can respond to the Chomsky universal grammar rules that I posted earlier - but I can say that he definitely proposed a genetic basis to grammar (See - Chomsky, 1965. N. Chomsky Aspects of the theory of syntax, MIT Press, Cambridge, Mass. (1965).).Thompsma (talk) 01:02, 3 March 2010 (UTC)
- "Moreover, as demonstrated by Noam Chomsky back in the 50's and 60's - there is a genetic basis to the grammatical structuring of language." Chomsky never proved that, and I would say Deacon's argument against and alternative are very persuasive. As to human culure having influenced biological evolution sure, sickele-cell anemia is an example, this is just Baldwinian evolution, it id old hat and can be discussed perhaps in the human evolution afrticle. Likewise one could quote Geertz' famous article on "Man makes himself" from his 1973 book on the role of cultureal feedack in the evolution of the human brain, this stuff is utterly uncontroversial. But let us stuck to the point. Biology still doesn't explain the evolution of culture. It odoes not explain the evolution of language (I guess you just gave in to my example above) and it certainly does not explain the evolution of say cubism in at. Up to a certain point, one can use paleolithic art as both an index for human evolution and as a formtive factor in human evolution, but as I and others have pointed out, you have to destinguish between the evolution of modern humans with a universal capacity for culture, versus the changes in cultures since then. Slrubenstein | Talk 21:40, 2 March 2010 (UTC)
- For the person who questioned the research about Chomsky in the 50's and 60's - I was referring to his innate generative grammar (see [53]). Chomsky along with Gould and others suggested that natural selection may not be the explanation for language. They suggested that emergent properties may explain the evolution of language; Chomskian universal grammar has been challenged, however, and it is now thought that language has been adapted to fit within the structure of the brain.[54] It is clear that genes and cutlure evolve in a reciprocal fashion (e.g., [55], [56]). The significant difference between humans and other apes is our cultural intelligence that allows us to navigate through social settings[57] where we express many prosocial behaviors and other traits responsive to cumulative cultural evolution.[58] However, when our higher order cognitive functions are tuned out - such as when doing repetitive tasks - our brains are functioning much like our primate cousins where homology and natural selection have had a significant evolutionary role. Hence, a section on cultural evolution might be helped by first outlining the similarities and differences in brain structure among cultural species. Once executive functions in the pre-frontal cortex of the human brain are called into action we take charge and express the sophistication behind our cultural traits[59], but even these make use of our sensory-motor systems and other parts of the more 'primitive' brain-stem.[60] Our imagination and other parts of our cultural underpinnings, such as morality, are consciously played out in the pre-frontal cortex - this is also the neural substrate where scientific hypothesis are formulated.[61] A person's cultural identidy is played out in the mind, which has a biological and a social basis. Cultural transmission may not follow through on the same principals as natural selection or genetic drift (although some claim it might, e.g. [62] or the memeticists). We can say for certain that cultural evolution and its biological underpinnings are inextricably linked if not inseperable. We can also see cultural evolution in other species - such as when populations of chimps inherit cultural traits, such as cracking oil palm nuts by observing elders. Cultural traits can and do evolve.
In conclusion: Cultural evolution is not a fringe science - it is an active area of research and should not be excluded from this article for the reasons suggested above. Cultural evolution is part of the biological sciences.Thompsma (talk) 07:17, 3 March 2010 (UTC)
- Of course cultural evolution is not fringe - scholars like Julian Steward, Andrew Vayda, and roy Rappaport remain very important. What is fringe is claiming that cultural evolution is biological evolution. Slrubenstein | Talk 17:58, 3 March 2010 (UTC)
- I am "the person who questioned the research about Chomsky" and above all you do is repeat back to me what I wrote to you, but with citations. Thanks for adding the citations. Now, you keep repeating the same two correct points, and the big non sequitor: yes, it is true that humans - what Deacon calls "the symbolic species," the species with culture, evolved, and thus culture as such which is to say that capacity or set of capacities chared by all humans is the product of human evolution, which is to a large degree biological. And second, being biological organisms, everything we do involves biological systems. Two correct points. But to them say cultural evolution is biological is just silly. I provided two examples of cultural evolution - French and Spanish evolving out of Latin, and Cubism evolving in Modern Art. And you have yet to show how any biological mechanism was the cause of either change. Slrubenstein | Talk 11:00, 3 March 2010 (UTC)
- Actually, I think Thompsma is just getting hung up on the word "biological". As far as I can see, all this comes down to is the contention that the term "biological evolution" should be used for evolution in any system underpinned by biology. Would you be happy then if cultural evolution were contrasted instead with, say, "genetic evolution"? The vital point here is that cultural evolution does not involve changes in gene frequency (in fact, that's almost the definition of cultural evolution—behavioural variation that can't be explained with reference to genetic, or epigenetic processes). And I'm sorry, but the term biological evolution is really very well established now as the term for evolution involving changes in gene frequencies. The term cultural evolution, moreover, is well established as the term for evolution in cultural systems that does not involve changes in gene frequencies. To protest looks rather unhelpful. garik (talk) 11:30, 3 March 2010 (UTC)
- And about your citations on language: these don't contradict my point at all; in fact they bolster it. Nothing I've said implies that culture and genes don't interact. No sensible person would ever pretend that they don't. And the Dediu and Ladd paper is a very nice example, with which I happen to be very familiar. I recommend reading it. The argument they make is that particular combinations of particular variants of two loci seem to have some bias on the likelihood of speaking a tone language. But there are two important points to make (which both Dan Dediu and Bob Ladd are extremely keen to stress): first, it's not deterministic. Having combination x of variants does not necessarily mean you'll speak a tone language. If it was deterministic, then there wouldn't be any cultural evolution involved at all. As it is, all that happens is that the particular combination of alleles in question presents a tiny bias. This bias is then amplified by cultural evolution, leading populations where this combination is common to be more likely to speak a tone language. In other words, the genetic bias is part of the environment to which the speakers' languages are adapting. The variation in the genes came about by biological evolution; the variation in the languages came about by cultural evolution, operating against the background of the genes. This is precisely why it's important to keep this sort of distinction clear. garik (talk) 11:43, 3 March 2010 (UTC)
- (I should add that the above two comments are aimed at Thompsma, which is who I mean by "you".) garik (talk) 14:37, 3 March 2010 (UTC)
- Sure - I think you are all correct and I have read all the papers I cited in here. It is also true that I am hung up on the term biological. I have not yet read Deacon's Symbolic Species - but his book has been sitting on my shelf for a few years now and I should get to it soon - I've browsed it several times and it looks interesting. I understand that biological evolution and cultural evolution are two established fields. This is perhaps one of the difficult parts to language - there are multiple uses for the terms we use. In context of Gaia - for example - culture falls under the umbrella term of biological. There are those, such as Lynn Margulis and James Lovelock, who have even suggested that space travel is Gaia's way of reaching out to reproduce. Certainly sounds like a mix-match of cultural and biological and where to draw the line? People have talked about biological evolution as though this is clear cut down to the genes, but the multi-level hierarchical view of evolution expands the concepts beyond the traditional 'biological' model of evolution - there are different explanatory principles operating at different parts of the hierarchy. The distinction that garik made about cultural vs. biological evolution is simply this - there are different explanatory phenomena for these different systems, but as Gould and others have pointed out the same is true for other aspects to the evolutionary puzzle. Biological evolution is not simply about genes milling about. What about the days when we would ridicule Lamark? Our advances in studying the microbial world has revealed a Lamarkian system in effect, "genes can move along a bewildering variety of routes between genomes: sliding through bridges between cellular membranes, hichhiking inside viruses, or even getting sucked up from the environment as naked fragments."[63] Smith and Szathmary[64] also proposed a Lamarkian system in cultural evolution. I am not advocating any of these views - simply stating ideas that have been proposed by other prominent evolutionary biologists. The point is that drawing a sharp line of distinction between biological and cultural gets fuzzy once you start to try and tease things apart. This article is about evolution. The argument that it is only biological draws an artificial line in the sand that does not exist in nature nor in the broader context of the literature.Thompsma (talk) 17:25, 3 March 2010 (UTC)
- And about your citations on language: these don't contradict my point at all; in fact they bolster it. Nothing I've said implies that culture and genes don't interact. No sensible person would ever pretend that they don't. And the Dediu and Ladd paper is a very nice example, with which I happen to be very familiar. I recommend reading it. The argument they make is that particular combinations of particular variants of two loci seem to have some bias on the likelihood of speaking a tone language. But there are two important points to make (which both Dan Dediu and Bob Ladd are extremely keen to stress): first, it's not deterministic. Having combination x of variants does not necessarily mean you'll speak a tone language. If it was deterministic, then there wouldn't be any cultural evolution involved at all. As it is, all that happens is that the particular combination of alleles in question presents a tiny bias. This bias is then amplified by cultural evolution, leading populations where this combination is common to be more likely to speak a tone language. In other words, the genetic bias is part of the environment to which the speakers' languages are adapting. The variation in the genes came about by biological evolution; the variation in the languages came about by cultural evolution, operating against the background of the genes. This is precisely why it's important to keep this sort of distinction clear. garik (talk) 11:43, 3 March 2010 (UTC)
- Actually, I think Thompsma is just getting hung up on the word "biological". As far as I can see, all this comes down to is the contention that the term "biological evolution" should be used for evolution in any system underpinned by biology. Would you be happy then if cultural evolution were contrasted instead with, say, "genetic evolution"? The vital point here is that cultural evolution does not involve changes in gene frequency (in fact, that's almost the definition of cultural evolution—behavioural variation that can't be explained with reference to genetic, or epigenetic processes). And I'm sorry, but the term biological evolution is really very well established now as the term for evolution involving changes in gene frequencies. The term cultural evolution, moreover, is well established as the term for evolution in cultural systems that does not involve changes in gene frequencies. To protest looks rather unhelpful. garik (talk) 11:30, 3 March 2010 (UTC)
- Time to end this thread. You are alone in your opinion Thompsma I'm afraid. None of us disagree that cultural evolution has a relationship with biological evolution, but it would be extremely unhelpful to expand on it in this particular article. Especially when we already have a perfectly good article on the subject elsewhere. --PLUMBAGO 18:06, 3 March 2010 (UTC)
- I will write the paragraph and I will introduce it here. I'm not alone in my opinion - some have supported inclusion of a paragraph on cultural evolution. The argument against including a paragraph on cultural evolution was that this article is only about biological evolution. You cannot find a researcher who studies cultural evolution without any reference to biological systems. Take a look at any modern introductory textbook on biology - cultural evolution is included - the same holds true for text books on evolution[65]. David Sloan Wilson talked about this extensively in his book 'Darwin's Cathedral' and in other publications on the evolution of social behaviours [66]. It is a biological subject matter. I have not advocated that culture evolves in the same way that genes do, but genes also do not evolve in the same way that populations or species do either. There have been many evolutionary transitions where novelty found its way, cultural evolution is no different. The planet once lived in a soup of genes where horizontal transmission reigned supreme - and in the world of bacteria this rule still holds true - vertical transmission is the novelty. Culture is a continuation of the story of biological evolution that is an emergent property and one of the important evolutionary transitions shifting from one complex system onto another. What is unhelpful is the immediate censorship that is being advocated rather than a focused discussion on the subject matter. Censoring this important part of evolutionary studies where much has been written is not wise and it doesn't help people to understand what evolution is about.
Cultural change is an evolutionary process acting on WITs. The evolution of cultures follows rules analogous to those governing the evolution of organisms, but they vary in their units of selection (cultural variants vs. genetic variants) and the method of transmission of successful variants to the next generation (learning vs. genes).
- [67] - emphasis added. If cultural change is an evolutionary process - then this seems like the correct place to introduce the topic - don't you think? If you want separate articles about the evolution of genes - then title it as such. The title of this article is evolution.Thompsma (talk) 19:27, 3 March 2010 (UTC)
The above quote emphasizes the differences between cultural and biological evolution. The above quote is a good reason not to include cultural evolution in this article. Now, Thompsa, not only do you keep ignoring my comments and criticism of your point, you keep introducing false information. You write that "You cannot find a researcher who studies cultural evolution without any reference to biological systems." Are you being deliberately obtuse? What do you mean by "biological systems?" Do you mean respiration and digestion? Then your point is silly, and you are just a disruptive editor wasting our time, of course any discussion of human beings will eventually mention breathing and eating. Or do you mean, "biological systems" as mechanisms or agents of cultural evolution? Then your point is simply false. The principle theorists of cultural evolution, Julian Stewart and Leslie White, as well as theorists refining the theory of cultural evolution, Marshall Sahlins and Elman Service, never mention "biological systems" in this way. Look, on your own talk page you admit that you use talk pages of articles to air your own views. It is time for you to go back to writing in your diary. Slrubenstein | Talk 19:58, 3 March 2010 (UTC)
- Thompsma - I count five editors against to one for (you) here. Where are these supporters of whom you speak in this thread? Slrubenstein is right - your quote above actually counts against your argument here. And the idea of "cultural variants" is pretty far from universally accepted last time I checked. While I generally buy into them, these ideas are still openly derided in some circles. The last thing an article on a theologically contentious (but scientifically accepted) topic needs is the insertion of scientifically debated material for which another article already exists. I'm done here. --PLUMBAGO 20:40, 3 March 2010 (UTC)
- I don't think this is appropriate to add this topic to the article, it is one of many forms of evolution that is best dealt with in the disambiguation page linked to at the top "This article is about evolution in biology. For other uses, see Evolution (disambiguation)." Tim Vickers (talk) 21:27, 3 March 2010 (UTC)
I want to propose that anthropology - including what passes as 'social' or 'cultural' in orientation - falls entirely within the domain of biology' (Ingold 1990: 208)[68]
- I have not ignored your (Talk) points - I read each post. I have also kept my comments polite and I ask that you do the same. I'm sorry - but there is no supreme being out there that we can consult to get the final answer on these difficult evolutionary questions. I'm not on here spouting of religious doctrine in opposition to evolution, nor have I stooped to insulting you in any way - I'm here to contribute. If you don't want to take part in a civil discourse - then leave and take your insults with you. The argument made was that cultural evolution is not biological evolution and should therefore be left out. The quote above is taken from a published anthropologist who argued exactly the opposite point.
I am confused. Ingold rejects Darwinian evolution biology (I apologize for my error). You agree with Ingold? So you reject Darwinian evolution? Slrubenstein | Talk 22:25, 3 March 2010 (UTC)
- He does not reject Darwinian evolution - you did not understand what he is trying to say. He rejects the vehicle/replicator approach that is so often used by Dawkins and proposes the replicator/interactor model that was also suggested by Gould and others. Read page 212 where he states how "Darwin so accurately characterized as 'descent with modification', guided by the universal mechanism of variation under natural selection." If Ingold doesn't suffice, let me turn to Edward Wilson:
Culture is biological: meaning in culture can be approached as the
outcome of mechanism-based causation, because culture stems from individual cognition,
which has a biological basis.[69]
- Look - I am not so concerned if cultural evolution is entirely biological. The position I am trying to argue here is that you cannot draw a line in the sand and say we will not include cultural evolution because it is not biological.
How, though, could culture itself be non-biological? The suggestion looks absurd. Biology is the study of life, and in the universe, so far we know, all culture consists of the activities of living beings.[70]
- You, Slrubenstein, have tried to paint me out as an idiot to suggest that culture is biological - yet there is ample evidence that this idea has surfaced many times over in the evolutionary literature. I am not saying that this is my position - do not judge me through guilt by association - I am trying to represent ideas that have been presented in the literature.Thompsma (talk) 23:15, 3 March 2010 (UTC)
- The contrasts you present in false representation of my own arguments are ludicrous!! I have taken great interest in peoples concept maps of things related to nature in relation to matters involving conservation - for example. I've studied in psychology and have examined how people view different concepts that puts people into different camps and positions. What I've come to understand is that people hold different world views or varied conceptual understanding of the terms that are used. Biological, natural and cultural are terms that have different interpretations, meanings and contexts of interpretation - the scientific use of these terms is no different. I'm not so dumb as not to realize that many of the great thinkers on evolution have made the distinction: "Cultural evolution is Lamarkian and very fast, whereas biological evolution is Darwinian and usually very slow.[71]" However, I have also read Lamark and he talked about biological evolution, albeit in a difference of opinion with respect to Darwinian evolution. So - if cultural evolution is Lamarkian and Lamarkian is biological - does it not stand to reason that cultural is biological?
Another one of your non-sequitors. Where does Wilson say that Lamarkian = biological? Slrubenstein | Talk
- He doesn't say this, I said that Lamarkian evolution is biological. What else could it be? When Lamark wrote Philosophie zoologique, ou Exposition des considérations relatives à l’histoire naturelle des animaux - he wasn't talking about moon rocks!! Now I suppose you are going to misconstrue what I am saying and suggest that I am a Lamarkian in your attempt to ridicule me even further. If a person reads and quotes the bible - does this automatically make them a Christian? No! Guilt by association was rejected long ago.Thompsma (talk) 23:15, 3 March 2010 (UTC)
- Moreover, many modern scholars view bacterial horizontal gene transmission akin to Lamarkian evolution in a way that is analogous to cultural transmission. I understand there are two processes at work here - but the terminology that has been used to separate culture evolution vs. biological evolution has simply been a matter of convenience, not one that is based on a philosophy that says there is a biological system of evolution and then there is a whole new thing going on that we call cultural evolution that is completely separate from biology. Cultural evolution is a biological phenomenon and a paragraph describing its meaning with a link to a main article belongs here where the topic heading is EVOLUTION. The heading is not EVOLUTION MINUS THINGS THAT MIGHT CONFUSE YOU OR A LITTLE CONTENTIOUS. What is this - evolution by a bunch of conservatives? Get with the program - their is a whole world of literature on cultural evolution and to censor it defies reason.Thompsma (talk) 21:33, 3 March 2010 (UTC)
Biology is the key to human nature, and social scientists cannot afford to ignore its rapidly tightening principles. (Wilson, 1978: 13)
Thompsma (talk) 21:33, 3 March 2010 (UTC)
- "many modern scholars view bacterial horizontal gene transmission akin to Lamarkian evolution in a way that is analogous to cultural transmission" - that is one of the oddest statements I've read on this talkpage. I've read a lot about HGT in both prokaryotes and eukaryotes and have never seen this described as a Lamarkian process (see recent review for a more mainstream view). Tim Vickers (talk) 23:01, 3 March 2010 (UTC)
The CAS system protects prokaryotic cells against phages and plasmids via a ‘Lamarckian mechanism’, whereby a fragment of a phage or plasmid gene is integrated into the CRISPR locus on the bacterial chromosome and is subsequently transcribed and utilized, via still poorly characterized mechanisms, to abrogate the selfish agent's replication.[74]
- I got the idea for that bit of info from a recent book I'm reading (p. 176, [75]):
As a biology student, I was taught to sneer at Jean-Baptiste Lamark, whose eighteenth-century theory of evolution was based on the diea of the inheritance of acquired characters...The more we study horizontal gene transfer these days, the more Lamarckian it looks.
- You can read Smith and Szathmary[76] where they talk about cultural inheritance being Lamarkian.Thompsma (talk) 00:07, 4 March 2010 (UTC)
- The CRISPR system isn't a type of HGT. I think rather than insulting the many people who disagree with you on this point, you'd be better to move on and accept that your opinions have not been met with agreement. Tim Vickers (talk) 05:50, 4 March 2010 (UTC)
- You just like to reject things - if you keep blocking out ideas you are not going to learn very much in life. It is important that you acquire knowledge - not reject it outright. How about some feedback from Lynn Marguilis (p. 162-5, [77]):
Undoubtedly this evolutionary mechanism has been underrated by neo-Darwinian biologists, since it corresponds to Lamarckian concepts of evolution. The establishment and the maintenance of a symbiotic association over generations may be viewed as an example of the "inheritance of acquired characteristics" (Lamark 1809)...Acquisition of the symbiont is a neo-Lamarckian process, whereas integration may require reciprocal adjustments in which mutagenesis and selection play a role.
Thompsma (talk) 18:05, 4 March 2010 (UTC)
- See also: Jablonkaa, E., Lamb, M. J., and Avital, E. 2004. ‘Lamarckian’ mechanisms in darwinian evolution. Trends in Ecology & Evolution, 13(5): 206-210 [78]
You are using Wilson and Ingold to suppot the same point, when in fact they hold opposing views. This means either that you do not understand what you read, or that you are disingeuous. Your silly logic, (Wilson says cultural evolution is Lamarkian, Lamark = biology, thus cultural evolution is biological) suggests to me that you are not disingenuous, you just do not know how to read. Slrubenstein | Talk 10:01, 4 March 2010 (UTC)
Let's go through this one more time and see who doesn't know how to read. The argument forwarded was - and I quote: "But surely this article is about biological evolution." I will copy and paste two of the quotes I put above so that you can read them again.
Culture is biological: meaning in culture can be approached as the
outcome of mechanism-based causation, because culture stems from individual cognition,
which has a biological basis.[79]
How, though, could culture itself be non-biological? The suggestion looks absurd. Biology is the study of life, and in the universe, so far we know, all culture consists of the activities of living beings.[80]
If culture is biological - then the question must be taken seriously - does it evolve by biological means? There are different biological explanations for genetic evolution, in the same way that there are different biological explanations for social evolution. The line you are drawing in the sand has been crossed - you are arguing this as though there is one static definition of biological evolution out there and I hardly doubt you could herd two philosophers into a room that would agree on this point. Have you spent any time reading Lynn Marguilis and how she had to overcome this sort of evolutionary censorship to have her theories related to symbiogenesis taken seriously? The same thing happened to James Lovelock and Gaia. Now look - these two have revolutionized evolutionary biology and they still have to battle with the lingering censorship with respect to what these two have had to say. Biological evolution is not a static thing, it is part of the scientific philosophy and holistic discussion that evolves. Holism is applied in ecology in as much as it applies to evolution. Cultural evolution is an emergent property of biological evolution and it is biological in the sense that Wilson describes above. However, all this doesn't really mater - because it is off topic. Foremost - I don't agree that cultural evolution should be subject to the evolutionary apartheid being advocated herein on the basis that this article is biological evolution only. I will not waste my time further on this futile discussion until I finish putting the paragraph together and will post it in here - like throwing my pet rabbit into a lions den. I've been accused of everything here - good thing I have a strong fortitude. Wikipedia can't present every viewpoint that is out there - but it should give a fair representation of what is being discussed. To be fair - a paragraph on cultural evolution belongs in the main article on evolution. People need to know that culture evolves and that there is a lot of interesting research in this area that is making important contributions to our understanding of evolution and understanding ourselves.Thompsma (talk) 18:05, 4 March 2010 (UTC)
- I repeat: "You are using Wilson and Ingold to suppot the same point, when in fact they hold opposing views. This means either that you do not understand what you read, or that you are disingeuous. Your silly logic, (Wilson says cultural evolution is Lamarkian, Lamark = biology, thus cultural evolution is biological) suggests to me that you are not disingenuous, you just do not know how to read." Neither of your quotes above respond to my point, since neither come from Ingold. Nothing of what you have written above responds to my point, since you are not addressing any of Ingold's ideas.
- Moreover, you still have not responded to my point about French and Spanish evolving out of Latin - this can be explained without any recourse to biological mechanisms. Cubism evolving out of modern art can be explained without any recourse to biological mechanisms.
- Moreover, you have still not responded to my point that the major theorists of cultural evolution, Julian Steward and Leslie White, do not identify it with biological evolution.
- Trying to discuss anything with you is like trying to play catch with a bumblebee. Now, solely for the pleasure of the viewing audience I want to see if i can play your game:
- If culture is material - then the question must be taken seriously - does it evolve by material means? There are different physical explanations for stellar evolution, in the same way that there are different physical explanations for social evolution. The line you are drawing in the sand has been crossed - you are arguing this as though there is one static definition of stellar evolution out there and I hardly doubt you could herd two philosophers into a room that would agree on this point. Have you spent any time reading Albert Einstein and how he had to overcome this sort of Tutonic censorship when he was a patent clerk - yes, Einstein worked in a patent office! - to have his theories related to seriously? The same thing happened to Linda Lovelace and cinema. Now look - these two both revolutionized their respective fields; this proves that one cannot understand the Russian or even the French revolutions without them! Similarly, stellar evolution is not a static thing. Do you have any doubt that stars revolve, and therefore the revolution of stars too comes into play? Thus, not only scientific philosophy but revolutionary politics evolve. Holism applies to these things, well, holism applies to everything, that is why we call it "holism." Therefore, it applies to you as well. Logically, therefore, you cannot disagree with me, this would be tantamount to disagreeing with yourself. Now, cultural evolution is an emergent property of stellar evolution in that it occurs ONLY on planets orbiting stars. However, all this doesn't really mater - because it is off topic. Foremost - I don't agree that cultural evolution should be subject to the evolutionary apartheid being advocated herein on the basis that this article is biological evolution only. I will not waste my time further on this futile discussion until (okay, I will waste my time just a little further) I finish putting the paragraph together and will post it in here - like throwing my pet rabbit into a lions den (which I have only done once, in order to prove that natural selection DOES occur). I've been accused of everything here - good thing I am a fortress of strength. Wikipedia can't present every viewpoint that is out there - but it should give a fair representation of what I have written on this and other talk pages. To be fair - a paragraph on my thoughts is not too much to ask especially when Wikipedia boasts of being the largest encyclopedia on earth (which need I point out is revolving around the sun proving that stellar evolution necessarily leads to planetary revolution), and since Wikipedia keeps growing larger, surely the significance of my paragraph will constantly grow smaller. People need to know that culture evolves! The don't think that culture evolves, if they did they would change the exhibits at my local art museum more often. But my wife keeps dragging me there on weekends, and I keep telling her, "Honey, you have to change," but she will not believe me until she can read it in Wikipedia. There is a lot of interesting research out there. Don't you see? re-search => re-volution? How could I make it any plainer for you?!?
- How's that? Slrubenstein | Talk 19:06, 4 March 2010 (UTC)
- I wasn't going to post anything - but had to say - great job! It was a fun read. I couldn't resist responding. If an introductory textbook on evolution had a section "about different physical explanations for stellar evolution" then I might also suggest that this be included. Until this day comes - I suggest we stick to the program. This is how ridiculous your retorts are. You create an artificial contrast and then suggest that these are the sorts of contrasts I am making. Your argument is flawed because you are misrepresenting my posts. I realize that we can't discuss all aspects of evolution, but surely you cannot think that cultural evolution is insignificant? Chapter 25 in Strickberger's evolution text - cultural evolution discussed[81], Barton's textbook on evolution - cultural evolution discussed (e.g., [82]), and Chapter 51 in the recent edition of Campbell's introductory biology textbook Unit Seven: Animal Form and Function at the end of the chapter on animal behaviour - cultural evolution with skill testing questions discussed. Stellar evolution? Nope - I don't see any chapters on this topic. However, Richard Dawkins did talk about Darwinism applied to universes in 'The Ancestors Tale': "Daughter universes are born in black holes produced by a parent universe, and they inherit its laws and constants but with some possibility of small random change-'mutation'. Those daughter universes that have what it takes to reproduce (last long enough to make black holes, for instance) are, of course, the universes that pass on their laws and constants to their daughters." There seems to be an overall trend, however, the biology texts are not talking about stellar evolution, neither was Lamarck. They are talking about evolutionary biology. How's that?Thompsma (talk) 21:26, 4 March 2010 (UTC)
- A serious response to a serious post: I think this is what disambiguation hats are precisely for. We use this article for the most popular use of the word and have disambig. hats for other notable uses of the term. Slrubenstein | Talk 23:32, 4 March 2010 (UTC)
- PS Thanks for having a sense of humor!
- I think that we are locked into a parallel debate this is occurring elsewhere[83]:
- I wasn't going to post anything - but had to say - great job! It was a fun read. I couldn't resist responding. If an introductory textbook on evolution had a section "about different physical explanations for stellar evolution" then I might also suggest that this be included. Until this day comes - I suggest we stick to the program. This is how ridiculous your retorts are. You create an artificial contrast and then suggest that these are the sorts of contrasts I am making. Your argument is flawed because you are misrepresenting my posts. I realize that we can't discuss all aspects of evolution, but surely you cannot think that cultural evolution is insignificant? Chapter 25 in Strickberger's evolution text - cultural evolution discussed[81], Barton's textbook on evolution - cultural evolution discussed (e.g., [82]), and Chapter 51 in the recent edition of Campbell's introductory biology textbook Unit Seven: Animal Form and Function at the end of the chapter on animal behaviour - cultural evolution with skill testing questions discussed. Stellar evolution? Nope - I don't see any chapters on this topic. However, Richard Dawkins did talk about Darwinism applied to universes in 'The Ancestors Tale': "Daughter universes are born in black holes produced by a parent universe, and they inherit its laws and constants but with some possibility of small random change-'mutation'. Those daughter universes that have what it takes to reproduce (last long enough to make black holes, for instance) are, of course, the universes that pass on their laws and constants to their daughters." There seems to be an overall trend, however, the biology texts are not talking about stellar evolution, neither was Lamarck. They are talking about evolutionary biology. How's that?Thompsma (talk) 21:26, 4 March 2010 (UTC)
Some researcheras believe that cultural and biological evolution could be unified. Cultural and linguistic processes might be subject to forms of selection not seen in biology, says Croft, such as when people follow the leader or the majority [10]. But ultimately, these are all different versions of the same thing. “I have to constantly fend off the view that applying evolutionary ideas to linguistics is an analogy,” he says. “It’s not an analogy: these are two different instantiations of a generl theory of evolutionary change. These are early days, but such a theory will give us insights that you can’t get just by looking at one domain.” Mesoudi agrees: “Cultural change and biological change share the same fundamental properties of variation, selection and inheritance,”
- I am one of those researchers who believe that the two are unified. You might also find: Jablonka & Lamb (2005)[84] an interesting read - they also propose a unified viewpoint and this has been picked up by others (e.g., [85]).Thompsma (talk) 00:16, 5 March 2010 (UTC)
- The mental masterbation is killing me. Often books contain what people think not necessarily what evidence based research supports. Dawkin's is notorious for publishing untestable hypotheses (as some critiques have published) so no matter how brilliant, novel, or logical an idea its still just an idea. I vote for leaving this out of the article because the subject is already addressed in a full article. Perhaps a brief mention if it fits. It doesn't have to do with it being a worthy subject as it already has a full article. We need to keep clear of what is just "ideas" of researchers in the field with evidence-based science. Seems this horse is dead. GetAgrippa (talk) 00:27, 5 March 2010 (UTC)
- Learn about epigenetic inheritance systems - then come back and make your arguments.[86], [87], [88] I've read your posts about genetics, language and what might constitute a Baldwinian bias otherwise known as the Waddington genetic assimilation - and it is clear that you don't have a good understanding of evolution decoupled and operating above the genetic level. There is such a bias toward genetic reductionism in here that people are unable to understand that there are other inheritance systems that are evolutionary in their scope.
Epigenetic inheritance in the broad sense is the inheritance of developmental variations
that do not stem from differences in the sequence of DNA or from persistent inducing signals in the present environment. As well as cell-to-cell transmission of epigenetic variations in unicellular and multicellular organisms (as will be explained below), the definition covers body-to-body (or
soma-to-soma) information transference that can take place through developmental interactions between mother and offspring (e.g., Weaver et al. 2004), through social learning (Avital and Jablonka 2000), and through symbolic communication (Richerson and Boyd 2005).[89]
I bold symbolic communication - because this falls under cultural evolution. Language is listed as one of the major evolutionary transitions via epigenetic inheritance systems and is covered under the heading of evolution through unifying principals of information storage and heridity.[90], [91]
Recent findings suggest that the emergence and subsequent evolution of very different hereditary systems, from autocatalytic chemical cycles to natural language, accompanied the major evolutionary transitions in the history of life...Following Chomsky’s theory about the innate quality of syntactic structuressz, some linguists and evolutionists argue that the evolution of syntax is the most important process in the evolution of mature language and that syntactic structures must be a result of biological evolution and not of cultural evolution (reviewed in Ref. 53).[92]
- I know I said I would refrain from posting on this thread - but I'm doing more research on this and feel the need to defend myself due to the level of criticism that has been launched at me. Here is a recent quote from cultural anthropologists[93] who have published extensively on the evolution of culture that might help this disucussion:
We can certainly make an analytical distinction between genetic and cultural influences on our behavior, and the influences of non-cultural forms of environmental influences. However useful, this analytical distinction emphatically does not license as an ontological separation of culture and biology separate levels of organization with only simple biological "constraints" on cultural evolution and diversity. Culture is as much part of human biology as bipedal locomotion, and cultural and genetic influences on human behavior are thoroughly intertwined.[94]
- From this we can establish:
- My proposal was rejected on the basis that this article is about biological evolution only. From the numerous quotes I have shown from peer-reviewed lit - this distinction does not seem to be at all clear. Hence, it is unjustified as a criterion of rejection.
- Cultural evolution is one of the major evolutionary transitions and to leave it out of this article ignores THE most important aspect to evolutionary theory - how did we evolve?
- Every major textbook on evolution has a section dedicated to cultural evolution, including introductory biology textbooks.
- I just don't know how anyone can argue that there is just cause to exclude a section on cultural evolution. It defies reason. This article should present a representative overview of what evolution is about.Thompsma (talk) 00:35, 6 March 2010 (UTC)
Thompsma, GetAgrippa knows more about epigenesis than you will know if you dedicate the rest of your life devoted exclusively to studying epigenesis; you would know that if you read what people wrote here as much as you wrote. Your comments show a fundamental lack of respect and it is no surprise people have stopped responding to you. Statements like "It defies reason" may seem to you like a bold rhetorical stroke but given just how many PhDs and professional research scientists are actively working on this article, frankly, it just makes you look stupid. I and others have pointed out that you are mixing up two different meanings of "cultural evolution," neither of which are appropriate to this page. Also, every time you use a quote to support your argument, you just provide more evidence for the view that, if you are not in high school, you have nevertheless not yet learned how to argue beyond a high school level and certainly do not know how to do university level (let alone professional) research. I frankly do not know anything about you personaly and I am not commenting on you, personally, I am comenting on the sophistic and amateurish way you argue. People have stopped listening to you and if you had any sense you would just shut up as the rational and adult response. At this point you are using this page as a soap-box, which violates Wikipedia policy.Slrubenstein | Talk 11:08, 6 March 2010 (UTC)
- Your comments are very typical of the PhD ego inflation hypothesis. My reason for being persistent is because I have a feeling that what is taking place here is a cultural phenomenon and an American bias. I don't know what country you are from - but in Canada there is a noticeable trend trend in American textbooks on evolution. The Kansas schoolboard and the other ID movement has created a fear and a defensive approach in presenting on the topic of evolution in the US. I suspect that the reason why there is an opposition to including a paragraph on cultural evolution. First it was claimed that cultural evolution should not be included because it is not biological evolution. I quoted Timothy Ingold[95] who made the argument that cultural evolution is biological evolution - but you rejected this based on and ill informed assumption that Ingold rejects Darwinian evolution, which couldn't be further from the truth. Ingold's ideas are sophisticated and to understand what he is saying you might need to know a bit about Gould, Lloyd, Hull and others who have talked about the philosophy of evolution through the notion of individuality, interactors and replicators applied to macroevolutionary principals - I think Gould's 'Ontogeny and Phylogeny' book also applies to Ingold's arguments. I suggest you take some time and read about professor Ingold's impressive academic history - who has written books on social evolution and he is also chair of social anthropology at the University of Aberdeen. To suggest that he is an idiot who has rejected Darwins theory of evolution means that you are reacting emotionally rather than intellectually to this discussion. Furthermore, talk talked about epigenetics earlier in this discussion: "The vital point here is that cultural evolution does not involve changes in gene frequency (in fact, that's almost the definition of cultural evolution—behavioural variation that can't be explained with reference to genetic, or epigenetic processes)." As quoted above, Eva Jablonka, Marian Lamb and even Eors Szathmary have gone to great length to explain cultural evolution as an epigenic inheritence system (e.g., [[96]] - you can also read a more expanded thesis on this through Jablanka and Lamb's book 'Evolution in Four Dimensions'). Hence, we have a contradiction here and I prefer to side with the peer-reviewed literature on this one. You keep saying my arguments are crude, disengenious and now you are accusing me of violating wikipedia policy simply because you don't agree! I am presening arguments that come from peer-reviewed literature that contradict some of the claims being made in support of excluding cultural evolution from this article. Hence, this strengthens my suspicion that this is an American cultural fear and bias stemming from the ID movement - which I also suspect is being strengthened and spreading as a result of the more cowardly response to withold information. It is our responsibility to present the science in its true form. If my supsicion is incorrect I cannot otherwise understand why cultural evolution would be rejected as part of evolution. I think it is important to tackle this bias because of its wide ranging social implications. I fully understand that cultural evolution, such as language, does not evolve solely by genetic means and I side with Jablonka and Lamb that epigenetic inheritance, cultural niche construction and genetic inheritance systems play a very important integrative role. However, the same can be said for niche construction as a macroevolutionary process in general - which is part of biological evolution (see [97]). Once you start looking at evolution as more than the shuffling of genes - cultural evolution is very much a part of the broader theory of biological evolution. All I am suggesting is a single paragraph - why such a strong backlash if it isn't based out of fear?Thompsma (talk) 21:37, 7 March 2010 (UTC)
- I also want to add that I agree with David Sloan Wilson's position in his book 'Darwin's Cathedral' - where he argues convincingly that cultural evolution holds the best untapped resource for understanding evolutionary theory. Cultural evolution applies to issues that are very pressing for our society, such as its implications for how we respond socially to the impending crises of our time.[98], [99] Wikipedia acts as an important media in its presentation of wordly topics to sections of society not covered in academic journals. Hence, beyond the academic arguments I made above, cultural evolution should be included in this main article for these reasons as well.Thompsma (talk) 22:01, 7 March 2010 (UTC)
- Here is an image I drew several years ago of how I think Ingold, Jablonka, Lamb, and other cultural niche constructionists might envision this problem: [100] The bi-directional arrows between each domain shows the influence of ontogenetic development (Dt) with respect to natural selection (NS). Looking at this image it becomes very difficult to disect biological evolution from cultural evolution. Some, such as Jablonka & Lamb have defined epigenetics to include social/cultural factors - I sub-classified them in my image as behavioural, cultural and group inheritance systems - some have simply lumped these together as genetic and ecological (Odling-Smee, 2007) - others have found four dimensions[101]. This is not about my own research - I'm simply showing this image to everyone to understand what others have said about this issue. If you are able to get the pdf - you can see that my image closely parallels and is very similar the image in Odling-Smee's paper[102], I've seen this in others that are of similar construction by this group of authors and reading their papers formed the basis of how I depicted my image. The model that distinguishes cultural from biological evolution is really about cultural evolution distinguished from the standard evolutionary theory (SET) depicted by Odling-Smee[103]. The SET model looks only at genetic inheritance. Odline-Smee and others have proposed an expanded theory. Gould - also knowleagable in this respect - was also smart enough not to make this distinction and referred to cultural versus morphological evolution. This article is not about what evolution was, but what evolution is. If we are to incorporate a NPOV and utilize a diversely held view on evolution - cultural evolution falls within the realm of biological evolution in the extended or multi-level evolutionary theory of Odling-Smee and others. David Sloan Wilson has also given a biological theory on cultural evolution - his book was a great read in this respect:
The purpose of this book is to treat the organismic concept of religous groups as a serious scientific hypothesis...My purpose is to see if human groups in general, and religious groups in particular, qualify as organismic in this sense.[[104]]
Thompsma (talk) 05:59, 9 March 2010 (UTC)
- I just found a link to Odling-Smee's website where he illustrates standard evolutionary theory (SET) [105] - which is essentially synomyous with the model of biological evolution that everyone in here was using to argue against my points. If you are arguing from the SET model - then everything that people said is true about cultural evolution and this is where the Meme#Criticism of meme theory comes into play. I have not been trying to advocate the meme concept. What I am trying to say is that cultural evolution is biological evolution in the way that Odling-Smee et al. illustrates extended evolutionary theory and cultural niche construction:[106]. My arguments are based on multi-level or extended evolutionary theory, not the SET model that everyone in here has been using to counter my arguments. Using biological evolution versus cultural evolution as a dividing line confuses the issue - we are talking a different language and things have progressed. Extended evolutionary theory also applies to group selection explaining prosocial behaviour. All this said - this is the complex debate. Some people have posted in here that they would like to see modern developments in evolutionary theory. The extended evolutionary theory is where the science has been moving by people such as Ernst Mayr, Stephen J. Gould, Edward Wilson, Odling-Smee and others. The extended evolutionary theory is more inclusive of what many evolutionists have been discussing in the literature - such as multi-level selection. I hope that I have managed to swing this debate away from childish insults and back to a reasoned discussion. I would like to simplify this into a paragraph about cultural evolution using the modern understanding of extended evolutionary theory and cultural niche construction - not through the reductionist SET model that looks at genetic inheritance only.Thompsma (talk) 23:14, 9 March 2010 (UTC)
The next quote is an example of niche construction being applied to the 'social brain' / cultural evolution and it was published in Science.[107] You will notice that cultural evolution is also described in relation to birds and other primates. This is explained by the biological evolution of culture using extended evolutionary theory - otherwise known as multi-level selection. Standard Evolutionary Theory (i.e., the outdated biological or gene only model for evolutionary theory that people argued about above) does not give a complete explanation for cultural evolution because it misses selection and inheritance of the niche. These authors use Olding-Smee's proposal for explaining the evolution of culture through ecological and genetic inheritance systems:
The evidence that brain size correlates with technical innovation and the acquisition of new food sources through social learning (or cultural transmission) in both birds (22) and primates (20) supports this claim. However, in the final analysis, all of these hypotheses (social and ecological alike) are at root ecological: They allow animals to survive and reproduce more effectively. The (Social Brain Hypothesis) SBH proposes that ecological problems are solved socially and that the need for mechanisms that enhance social cohesion drives brain size evolution...In effect, we are dealing explicitly with multilevel selection and the long-overlooked topic of niche construction (38).
- emphasis added.Thompsma (talk) 04:22, 10 March 2010 (UTC)
- The most amazing part to this discussion is that I have been combating a culturally predictable behaviour: "A subset of chimpanzees that discovered the alternative method nevertheless went on to match the predominant approach of their companions, showing a conformity bias that is regarded as a hallmark of human culture."[[108]] I would hope that people in here would have the cognitive aptitude to escape this conformity bias and learn the concepts rather than poke insults at me. Guppies exhibit this same type of behavior - put a female in a tank she will go for a colorful male, but put a fake female near a drab male and she will compete for the drab male. People in here are conforming and gravitating toward the drab cultural evolution hypothesis. Those who stooped to low brow insults now have some apologizing to do and should concede that cultural evolution is explained by biological evolution using multi-level selection or extended evolutionary theory.[109] This was even called mental masturbation - but what an uphill battle I have had to fight in this playground! I've tried to overcome this bias time and time again - but people always revert back to the same old gene reductionist arguments, which are not helpful nor are they representative of what evolution is about.
- Can we now move on and enter this discussion in a more collaborative way? I am hoping that people will actually move away from the stupid debate asking the question - is cultural evolution based on biological evolution (answer: OF COURSE IT IS!!) - and actually start to focus on the topic at hand. The topic I want to concentrate on is how to incorporate a section on cultural evolution into this article. Alternatively, this article could support a section on the extended evolutionary theory - which is what I argued last month - with a sentence or two of how this explains cultural evolution. Much of this article skims over multi-level selection as though it is a peripheral hypothesis - when in actuality it is at the heart of evolution. These ideas keep meeting tough conformist resistance in here - yet they are popping up in the peer-reviewed literature and textbooks where the most exciting, novel and profound discoveries in evolution are being discussed. Let's not keep one of the most profound evolutionary transitions and the best example of evolution - i.e., cultural evolution - as our little in house secret. Work with me and present the ideas in their proper representative form.Thompsma (talk) 21:02, 10 March 2010 (UTC)
- If the article "skims over" the "novel" ideas that are only now "popping up" in advanced sources then it is giving the correct amount of weight to these novel ideas. Once people stop talking about if the modern synthesis should be extended and actually extend it into a new synthesis, then these ideas will have entered the mainstream and we can rewrite this article around the new synthesis. However we should not present minority views as if they are universally accepted. Tim Vickers (talk) 21:38, 10 March 2010 (UTC)
- You must have a short-term memory. These are not minority views Tim - they are published extensively. You keep saying that multi-level selection is a minority view. Whatever you mean by minority view - I have no idea!? Multi-level selection was discussed at great length by Stephen J. Gould - he spent his entire career working on this. Are you going to start telling me that Gould holds a minority view? We already went through this entire debate - Elizabeth Vrba, Niles Eldridge, Alan Templeton, Ernst Mayr, Edward Wilson, David Sloan Wilson, Marion Lamb, Eva Jablonka, Richard Lewonton, Kevin Laland, Lynn Margulis, Susan Oyama, David Jablonski, Odling-Smee and many others - all discuss multi-level selection at great length. These ideas are published in Science, Nature, Evolution, Animal Behavior, PNAS, The Quaterly Review of Biology, Paleobiology and so on. How many papers and books must be published before you start to see that the extended evolutionary theory is not a minority view? If you have your own opinion - just the way you rejected the Lamarkian context for the CRISPR system above - then I suggest you take it up with the editors of the journals and the authors of the articles.Thompsma (talk) 22:04, 10 March 2010 (UTC)
- I was quoting your earlier remarks that described these concepts as "exciting, novel and profound" that are "popping up in the peer-reviewed literature". I agree completely, these novel ideas may one day indeed revolutionise evolutionary biology. Tim Vickers (talk) 02:46, 11 March 2010 (UTC)
- Okay TimVickers - thanks for your response! A few things to add:
- Darwin was the first to ponder group selection - hence, it really isn't a 'new' addendum to evolutionary thinking.
- I should appologize because there was a little bit of confusion at the start. There is a historical case for the contrasting usage of biological vs. cultural evolution in the sense of the standard evolutionary model vs. cultural evolution that has been described by Odling-Smee and others. I had been so wrapped up into the modern literature lately that I forgot about this old contrast. Most papers that make this contrast (i.e., biological vs. cultural evolution), however, make clear at the start what they mean by biological evolution to mean Darwinian forces acting on genes or phenotypes. Personally, and other's in the literature agree, I think this contrast is nonsensical and should not be used - it is all biological evolution.
- I should also make clear that most people think genes are strings of DNA, but even Richard Dawkin's has made the distinction: "The Williams gene is only incidentally made of DNA. He later (1992) called the generalised version (what I would call a replicator) a codex, adding, “A gene is not a DNA molecule; it is the transcribable information coded by the molecule.”"[110]. Further reading on Sewall Wright's classical analysis on what constitutes a gene through to modern lit and as a practicing geneticist I have always found it odd that people conceptualize genes as a thing that can be pinned down quite easily. In contrast an idea or 'meme' is rejected because one is seen as a clear and cut replicator whereas the later is not. This is not in defense of the meme and I have no intent to introduce that idea in a paragraph on cultural evolution - except perhaps in passing - this is just making clear to everyone that genes are not simple bits that we can all understand and agree upon. This part of the science is still not as settled as people think it is.
- The multi-evolutionary perspective is not settled either. It is unfortunate that we have not had another Darwin to put some of these conflicting ideas to rest and it is unlikely that this will ever happen. The multi-evolutionary perspective - or extended evolutionary theory - is likely not to be settled even for another thousand years (if we survive that long) as people debate the semantics of absolute vs. relative fitness, old vs. new group selection and so on. If we were to write on settled science - I doubt we could say much at all. Debate continues, but it is clear in the pluralism of ideas that the cultural niche through extended evolutionary theory is considered to be biological and evolutionary in its explanation and it is a serious part of the study - from Darwin to present evolutionists have taken multi-level selection seriously.
- If this article is about 'biological evolution' - then we should introduce what evolutionary biologists are saying about cultural evolution. There are some clear-cut elements to cultural evolution that are generally accepted and can be summed up in a simple paragraph or two. I think this is an opportune time to introduce expanded evolutionary theory using niche construction as a way of explaining cultural evolution. I've started tinkering on this in my sandbox - it is in an early draft stage, but I hope to introduce it in here soon. It does not seem wise to preclude a very significant part of evolutionary theory, research and discussion on one of the great evolutionary transitions. Cultural evolution is as much part of evolution as are genes. Hence, we should not leave people in the dark and to leave them thinking that evolutionary biologists have not been working on this topic in a serious way. Moreover, cultural evolution applies not only to humans, it applies to life in general - from birds to slime molds - the principals have been discussed and applied throughout the lit.Thompsma (talk) 01:02, 13 March 2010 (UTC)
Four causes article: is modern science teleological or does it at least attempt the opposite?
There is discussion at Four causes relevant to this article. It is being claimed that "Most modern theories of evolution are unabashedly teleological", and it is being argued that the article should remove references to modern science not being teleological and say the opposite. Comments please.--Andrew Lancaster (talk) 09:08, 13 March 2010 (UTC)
Evolution is not teleological. However writers often use teleological language as a sort of shorthand. For example, here's an actual quote from an evolution paper I recently read:
- In the arguments developed in this paper, the proper but cumbersome way of describing change by evolutionary adaptation has been substituted by shorter overtly teleological statements. This should not be taken to imply that evolution proceeds by anything other than from mutations arising by chance, with those that impart an advantage being retained by natural selection.
Evercat (talk) 10:41, 15 March 2010 (UTC)
Heredity
The heredity section of the article misses one of the simple ideas caught in the following quote from Watson & Cricks (1953) landmark paper[111]:
"It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material."
Suggestion to article in bold:
Heritable traits are passed from one generation to the next via DNA, a molecule that encodes genetic information.[30] DNA is a long polymer composed of four types of bases. The sequence of bases along a particular DNA molecule specify the genetic information, in a manner similar to a sequence of letters spelling out a sentence. DNA is heritable because the specific pairing of the four bases provides a biochemical mechanism that cells use to accurately transcribe and replicate coded information from one template to another.
I'm restoring what I had originally suggested above - I would prefer that my posts remain unchanged so that others can see what I proposed, thank you.Thompsma (talk) 07:03, 23 February 2010 (UTC)
The next sentence should then follow in a new paragraph.Thompsma (talk) 17:46, 22 February 2010 (UTC)
- To me this seems to be wandering off our topic, our readers will know that heredity works, and they don't need detailed knowledge of how heredity works to grasp the idea of evolution. Equally, we could discuss the molecular mechanism of mutations, or recombination, or HGT, but all of these would be side-issues and just act as distractions. Tim Vickers (talk) 19:19, 22 February 2010 (UTC)
- One sentence explaining Watson-Crick complementary base-pairing is a distraction and wandering off the topic of heredity? It seems to me - I might be wrong - that this was one of the important discoveries that lead to a crucial understanding of how the genetic material was heritable through biochemical means. Why even bother mentioning that DNA is a polymer made of four base pairs? The story might was well be completed with a simple sentence - not necessarily what I proposed, but something to the effect that Watson-Crick complementary base-pairing explains how DNA is able to replicate copies (i.e., heritable), otherwise some people might think that there is some kind of intelligent interpreter reading off the code.Thompsma (talk) 20:17, 22 February 2010 (UTC)
- Actually the current version of the lead doesn't mention DNA any more, although it does assume that the reader knows what "changes the sequence of a gene" will mean. I'll edit the version above to fix this. Tim Vickers (talk) 21:06, 22 February 2010 (UTC)
- This wasn't a suggestion for the lead. The paragraph I pulled was taken from the sub-section on heredity. I'm actually just going to go ahead and make these modifications, because they should be included in the heredity section.Thompsma (talk) 07:11, 23 February 2010 (UTC)
- Ah I see, sorry. My mistake. Tim Vickers (talk) 20:11, 23 February 2010 (UTC)
- Yup..your response seemed a little odd, but then I figured out your mistake. You're correct though - the lead might be improved with a sentence on DNA.Thompsma (talk) 20:35, 23 February 2010 (UTC)
The Watson-Crick quote seems to be inaccurate based on our modern understanding of replication. The quote seems to suggest that the interaction between bases is important for incorporating the proper base in the growing DNA strand, however, this is simply not the case. The DNA polymerase itself determines what base to incorporate into the growing DNA strand based on the interaction between the polymerase and the template base, not an interaction between to complementary bases. See Moran et al.'s "A thymidine triphosphate shape analog lacking Watson–Crick pairing ability is replicated with high sequence selectivity". In other words, it seems plausible that high fidelity replication could be achieved using an arbitrary mapping between the template strand and the daughter strand. The importance of Watson-Crick base pairing isn't in its ability to enable replication, but in the ability to accurately align the template and daughter strand once synthesis is complete, which allows DNA repair. —Preceding unsigned comment added by 99.31.14.167 (talk) 12:29, 19 March 2010 (UTC)
Reverted lead
I've just reverted part of the recent changes to the article by Cosmic Latte (talk · contribs). I think it would be advisable to discuss such alterations here first. Firstly, I think this article should solely focus on the biological meaning of "evolution" as opposed to other meanings of the word "evolution". As such, many articles in similar positions begin with the words "In [mathematics/statistics/political science/biology/etc.] ..."
This is not a huge issue, though. More importantly, I don't think it's a good idea to define evolution as a "process" in the first sentence. Evolution is the change in traits. As such, evolution is more of an observation. Natural selection, genetic drift, etc. — those are the processes. Gabbe (talk) 10:24, 21 March 2010 (UTC)
- You're probably right about the word "process". My issue with the phrase, "in biology", is that it sounds almost like a contingency--as if the veracity of evolution somehow rested upon the integrity of biology. Well, in a sense, perhaps it does: As subjective "observers", biologists perceive evolutionary evidence and events in accordance with their own, subjective grasp of concepts, such as "fitness" and "function", which the philosophy of biology does not simply take for granted. I, probably along with many editors of this article, can appreciate a sense in which the perception of evolution-as-object is contingent upon the theoretical bent of biologist-as-subject. But will the average reader catch this? My fear is that, if people read that evolution means one thing "in biology", they might suppose that it just as well could mean something else (or mean nothing at all) "in", say, creationism or some other "alternative" to a biologically sound world-view. I certainly don't read that much into the two words, "in biology", but I'm trying to put myself in the shoes of the not-especially-biologically-literate reader here. If nothing else, there's just a faint feel of unintended contingency in the "in biology" opening. I realize, of course, that "in biology" is shorthand for something like "in biological terminology". But even if "in biological terminology" is something of a mouthful, it still might be preferable to the semantic flexibility of "in biology" (and, admittedly, to the semantic inaccuracies of "biological process"). Cosmic Latte (talk) 14:56, 21 March 2010 (UTC)
- P.S. Please don't feel compelled to respond to every convoluted bit of what I said above. I blabber way too much when I've had enough caffeine. Overall though, I just would like to suggest that "in biological terminology" might help to avoid unnecessary ambiguity. Cosmic Latte (talk) 17:07, 21 March 2010 (UTC)
- Believe me, I felt pretty much the same way you do when I first read this article. Just like you say, I think that the lead sentence
- In biology, evolution is ...
- is supposed to be a succinct way of saying
- In biological terminology, the word "evolution" refers to ...
- but inserting the latter text instead would typically be considered bad writing (see WP:REFERS). I agree with you that the current wording isn't optimal either, being perhaps too terse to properly convey the intended meaning. I'm not sure how to improve it, though. Let's see if anyone else chimes in, otherwise I'd take it as a tacit approval and proceed with your suggested "terminology". Gabbe (talk) 17:57, 21 March 2010 (UTC)
- Another alternative might be something like this: "Evolution is the biological complex of processes whereby the inherited traits of a population of organisms change through successive generations." In trying to find an umbrella term for multiple "processes", I thought of "complex". Just to be on the safe side, I plugged the line, "Evolution is a complex of processes", into Google--and, sure enough, I got a reliable-looking hit. How does this new suggestion sound? Cosmic Latte (talk) 00:17, 22 March 2010 (UTC)
- Believe me, I felt pretty much the same way you do when I first read this article. Just like you say, I think that the lead sentence
I don't know. Most biologists define evolution as the actual change in allele frequencies in a population from one generation to the next, the complex of processes are what explains evolution. See for example:
- "In fact, evolution can be precisely defined as any change in the frequency of alleles within a gene pool from one generation to the next." from Helena Curtis and N. Sue Barnes, Biology, 5th ed. 1989 Worth Publishers, p.974.
- "Evolution is [...] changes in gene frequency within a population" from Ridley, M. 2004. Evolution. 3rd ed. Oxford: Blackwell Pub., p.227.
- "By the mid-20th century [...] 'evolution' was redefined as 'shifting gene frequencies,'" from Stoltzfus A (2006). "Mutationism and the dual causation of evolutionary change". Evol. Dev. 8 (3): 304–17. doi:10.1111/j.1525-142X.2006.00101.x. PMID 16686641.
and so on. Many laymen will probably use "evolution" as a shorthand for natural selection or common descent, but "in biology" evolution is the change in inherited traits through successive generations. The complex of processes are what explains why and how this occurs. Gabbe (talk) 07:41, 22 March 2010 (UTC)
- Then how about either of the following?
- "Biological evolution is the change in the inherited traits of a population of organisms..." Short and sweet. (Well, short, but maybe a little sour to the eyes, which have to deal with a Wikilink immediately preceding the WP:BOLDTITLE. But, maybe not too bad.)
- Evolution is a biological phenomenon whereby the inherited traits of a population of organisms change..." Somewhat more of a mouthful, but it looks (IMO) a bit tidier. And since "phenomenon" covers anything that can (even in theory) be observed, it might be the best (or even the only suitable) umbrella term for all of the evolutionary processes.
- Or, maybe the "terminology" route is the way to go. Just, hopefully something that'll avoid the hint of relativism that "in biology" seems to hold. Cosmic Latte (talk) 18:14, 22 March 2010 (UTC)
- Yeah, either one of those three options ("Evolution is the biological phenomenon...", "Biological evolution is..." or "In biological terminology...") look OK to me. As I said before, it might be advisable to see if anyone else has something to say here, otherwise I'd interpret their silence as a tacit approval and proceed with one of those three. Gabbe (talk) 18:34, 22 March 2010 (UTC)
Perhaps I'm being too simple, but could I recommend removing 'In biology' from the lead? Is it even necessary, when so much debate is going over it? "Evolution is the change in the inherited traits of a population of organisms through successive generations." For example, the article Heredity does not start off with 'In biology'. The 'In _______' clause is generally used to differentiate the term from similar terms, but I think that the when people mention 'evolution', they are talking about biological evolution. DanEdmonds (talk) 14:15, 23 March 2010 (UTC)
- You're probably right, especially since the Template:About at the top of the page already makes it quite clear that this article is about the biological variety of evolution. I assume we all can agree that "in biology" needs to be either altered or removed--and I'm leaning increasingly towards removal. Cosmic Latte (talk) 15:04, 23 March 2010 (UTC)
- Fair enough, I'm not particularly interested in keeping it either. Gabbe (talk) 15:16, 23 March 2010 (UTC)
- Excellent. I'm glad we could find a simple solution to such a simple problem. Often they're the best :-). DanEdmonds (talk) 15:56, 24 March 2010 (UTC)
- Fair enough, I'm not particularly interested in keeping it either. Gabbe (talk) 15:16, 23 March 2010 (UTC)
Change in heredity
I'm concerned that the sentence "DNA is heritable because the specific pairing of the four bases provides a biochemical mechanism that cells use to accurately transcribe and replicate coded information from one template to another." gives the impression that DNA would not be heritable if there were no complementary base pairing, which is, I believe, incorrect. I left an anonymous comment earlier summarizing my opinion on this, but since nothing has been done for a few days I decided to change the article to force some people to comment ;). To the best of my knowledge DNA's complementary structure is important for annealing and all the DNA repair pathways which depend on double strand information (which is almost all of them), but has no particular importance to replication, and therefor no particular importance for heredity. Therefore, I simply propose removal of this sentence.Matthew Ackerman (talk) —Preceding undated comment added 12:33, 23 March 2010 (UTC).
Whoops, I guess I can't make the change myself, at any rate, I would like to see the change made, or at least get some feed back on why it shouldn't be made.Matthew Ackerman (talk) —Preceding undated comment added 12:36, 23 March 2010 (UTC).
- I looked around in the literature. You seem to be right. Narayanese (talk) 21:56, 23 March 2010 (UTC)
Third sentence of the lead
Hello, I was just perusing this article randomly and I have a suggestion for the third sentence of the lead paragraph. It reads "Anatomical similarities, geographical distribution of similar species and the fossil record indicate that all organisms are descended from a common ancestor through a long series of these divergent events, stretching back in a tree of life that has grown over the 3,500 million years of life on Earth." I have two comments on this sentence.
1) First, it seems to me that the purpose of the sentence is to lay out, at the highest level, the independent lines of evidence in support of evolution. As such, I think that DNA (or genetic) similarities is a fourth line of independent evidence of the same level of importance as the three lines already listed in the sentence. Certainly, those three lines of evidence are the ones Darwin primarily relied upon when he laid out the theory (actually, he more apologized for the fossil record than relied upon it as an independent source of supporting evidence), but I think the incorporation of genetic evidence into the theory of evolution is at least as important a source of independent evidence and should be included in this sentence.
2) Secondly, for both anatomical similarities and genetic similarities, it's not so much the similarities per se that are crucial, it's the pattern of those similarities. The article states later that it's the fact that these similarities can be classified into a hierarchy of nested groups that is key to their support of the theory of evolution. I understand the lead isn't supposed to go into all the detail that is laid out later in the article, but I still feel it's crucial to say something about how it's the nature of the similarities that's important.
I might suggest: "A nested hierarchy of anatomical and genetic similarities, geographical distribution of similar species and the fossil record indicate that all organisms are descended from a common ancestor through a long series of these divergent events, stretching back in a tree of life that has grown over the 3,500 million years of life on Earth." for that sentence. Bgplayer (talk) 18:33, 29 March 2010 (UTC)
- That sounds like a noteworthy addition and doesn’t seem to be a large or controversial contribution. Just add it into the article. If it is removed then it can be discussed in more detail as to why here. Andrew Colvin (talk) 05:24, 30 March 2010 (UTC)
Changes to evolution in action at FAQ
I've just altered the FAQ's fifth question, giving better examples of observations of evolution in action. The peppered moth was really bad example, since it is now quite likely the whole matter was a fraud. —innotata 20:44, 25 March 2010 (UTC)
It does not appear that you altered anything and the peppered moth example, according to the peppered moth evolution article is not a fraud. Andrew Colvin (talk) 06:41, 28 March 2010 (UTC)
- Actually, Innotata removed peppered moth as an example. I think it can be safely readded. Gabbe (talk) 08:12, 28 March 2010 (UTC)
- Since there is even a minor sensible doubt that the peppered moth observations are either inaccurate or fraudulent, it would be best to use the many recent, meticulously recorded examples instead. —innotata 19:51, 29 March 2010 (UTC)
- There really is no doubt. No support has been found for the accusations of error or fraud. thx1138 (talk) 16:19, 4 April 2010 (UTC)
- Actually to be more precise, Majerius did find fault with Ketterwell's experiments with the Peppered moth, and planned to redo the experiments to prove the premise is correct (published in Science). The tempest in a teapot arises from the fact other researchers before and after Ketterwell had addressed the peppered moth and provided evidence to support natural selection in the peppered moth. That was a few years back and I don't remember if Majerius ever published an article, but Cook had and is still examining selection and gene flow in the peppered moth. Regards GetAgrippa (talk) 16:24, 9 April 2010 (UTC)
- There really is no doubt. No support has been found for the accusations of error or fraud. thx1138 (talk) 16:19, 4 April 2010 (UTC)
- Since there is even a minor sensible doubt that the peppered moth observations are either inaccurate or fraudulent, it would be best to use the many recent, meticulously recorded examples instead. —innotata 19:51, 29 March 2010 (UTC)
Global Warming citation?
With the current release in the factual data concerning Global warming (or the actual lack thereof), I find it disreputable to blame extinction on global warming in this article. If there is no scientific basis in any capacity for global warming's existence in the first place, then it follows suit that there exists no extinction based off of the fallacy. —Preceding unsigned comment added by 74.189.70.34 (talk) 19:58, 8 April 2010 (UTC)
- That you may doubt the existence of anthropogenic global climate change doesn't change the fact that reliable scientific sources consider it to be an important concept with far-reaching consequences, including a role in species extinction. — Scientizzle 20:03, 8 April 2010 (UTC)
- There are a number of books and peer-reviewed articles addressing global warming in past extinction events. Global warming is hypothesized to be partly responsible for the present Sixth Glogal extinction event that appears to be happening now. Even if some of the global warming data is fraudulent it doesn't mean all of it is, and the issue hasn't been there is global warming as what is the cause (anthropogenic causes,evolution driven extinctions,bolide collisions, volcanic, etc.). However I remember back in the 70's climate scientist were expecting another mini-ice age, however climate models were very poor then and really just until recently have they had any power. Today's model appear more predictive. In any case global warming , as extinction events, appear a normal part of earth's history. Hypotheses about warming oceans releasing the huge reservoirs of methane in clathrates is a real possibility with devasting effects on oceanic and terrestrial life. Regards GetAgrippa (talk) 16:37, 9 April 2010 (UTC)
- 74.189.70.34, whether you believe in global warming, doubt global warming, disagree with global warming, don’t trust the scientists, or any other form of opinion about global warming; it is completely irrelevant to what is fact, to what is known, and to what the evidence shows. Wikipedia distinguishes—just like any other academic or scholarly writing—what’s factually true with what’s belief based on personal “fact” or “truth”. Whether you like it or not, Wikipedia follows the evidence to guide in its writing. If you don’t trust or like the evidence, that’s just too bad. I am not trying to attack, but the evidence is evidence. If you can find sources and scholarly evidence to support your opinion, please feel free to discuss and add to the article. Andrew Colvin (talk) 05:22, 10 April 2010 (UTC)
- There are a number of books and peer-reviewed articles addressing global warming in past extinction events. Global warming is hypothesized to be partly responsible for the present Sixth Glogal extinction event that appears to be happening now. Even if some of the global warming data is fraudulent it doesn't mean all of it is, and the issue hasn't been there is global warming as what is the cause (anthropogenic causes,evolution driven extinctions,bolide collisions, volcanic, etc.). However I remember back in the 70's climate scientist were expecting another mini-ice age, however climate models were very poor then and really just until recently have they had any power. Today's model appear more predictive. In any case global warming , as extinction events, appear a normal part of earth's history. Hypotheses about warming oceans releasing the huge reservoirs of methane in clathrates is a real possibility with devasting effects on oceanic and terrestrial life. Regards GetAgrippa (talk) 16:37, 9 April 2010 (UTC)
Darwin's Caricature
I remember reading in a biology book that the caricatures of Darwin were made to ridicule his points of view. Not to "symbolize evolution" as it says under the drawing on the "social and cultural responses" section. Can someone check it out please? —Preceding unsigned comment added by 189.24.57.10 (talk) 04:23, 5 April 2010 (UTC)
- Your recollection of a biology book may well be correct, the citation for this statement is to Janet Browne, a noted historian commenting on the responses to Darwin's publication of his views. Darwin legitimised the pre-existing discussions of transmutation, which had been popularised in Britain and America by the anonymous "author of Vestiges". Darwin's eminence as a scientist and public figure, as well as the very recognisable beard he grew during illness immediately after publication, made his caricatured image, often with an ape or monkey body, symbolic of evolutionary views in general. . dave souza, talk 23:32, 22 April 2010 (UTC)
Goethe and Geoffroy
I see no mention of either Johann von Goethe or Étienne Geoffroy Saint-Hilaire in the history section, whereas they are the two biggest pioneers of the subject of evolution, according to both Darwin’s Historical Sketch, and Henri Lecoq 1854 synopsis of the subject:
- "We see that our researches on the fixity or the variation of the species, lead us directly to the ideas issued by two men justly famous, Geoffroy Saint-Hilaire and Goethe."
As commented in 1892 by German physicist Hermann von Helmholtz:
- "Goethean morphology had so shaped nineteenth-century biology that it paved the way for Darwin’s theory."
An overview on Goethe’s evolution theory (1786-1809) can be found here:
- Johann Goethe – Encyclopedia of Human Thermodynamics
—Preceding unsigned comment added by 75.3.85.40 (talk) 17:22, 17 April 2010 (UTC)
- Back again Libb Thims? You were banned for very good reason. Please don't return. Tim Vickers (talk) 22:12, 22 April 2010 (UTC)
Theory?
See the FAQ above, Evolution as theory and fact (and related articles), and WP:FORUM. |
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The following discussion has been closed. Please do not modify it. |
Maybe I'm mistaken but isn't this a theory? If it is it should be presented as such rather than as if it is 100% factual. Yes I realize many scientists clutch to this belief tighter than Christians to Bibles so please don't bring that up. Thanks :) Xx IzzyReal xX (talk) 19:28, 14 April 2010 (UTC)
You might say "just a hypothesis", but a scientific theory is a hypothesis which has gained wide acceptance under peer review by the scientific community. Until proven false, a theory provides the most complete explanation of natural phenomena based on scientific observation and study. —Preceding unsigned comment added by Montreux (talk • contribs) 05:17, 19 April 2010 (UTC)
Need better definitions for "create new DNA" here. See meiosis and mitosis for examples of "new" DNA creation. Happening right now within you and without you. __ Just plain Bill (talk) 15:45, 13 May 2010 (UTC)
Sorry, I phrased that wrong. However, I see that whatever I say, you are probably not going to change your minds about his. TheMan888 (talk) 02:04, 14 May 2010 (UTC)
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Complexity and Diversity
I was just reading my latest Science and came across a very interesting article by Doebeli and Ispolatov about Complexity and Diversity. It not really something that should be added to this article but it does make for some fascinatin' and interestin' reading. Food for thought! This edition also has several articles related to science education that educators would find interesting. Regards GetAgrippa (talk) 12:33, 4 May 2010 (UTC)
Computer Models
(First wikitalk post so don't really know things are done here...) Saw in the archives some questions about computer modeling of evolution. There is actually a growing field called Evolutionary Dynamics. It's largely headed by Dr. Martin Nowak from Harvard. It consists of models of evolution based on game theory and social networks. He's written a textbook on the subject titled "Evolutionary Dynamics" (surprising ehh?) which I have not read. My knowledge on the subject comes from a lecture he gave while visiting Hopkins. The focus of the talk was simulating the evolution of cooperation.
It basically concluded that cooperation can theoretically evolve in a population under certain circumstances (# of individuals in population, network of how they interact). It is not a stable state, meaning that once cooperation evolves, defectors gain an evolutionary advantage. However at this point, tit for tat strategies gain the advantage at which point cooperation again gains the advantage. In general, this requires individuals to be sufficiently networked. By this, I mean it is likely that person A knows something about person B (like history of actions) and that they are likely to interact in the future. Nowak mentioned how this is also a possible evolutionary pressure for social intelligence and language. It is advantageous to know someone's history of actions and language is the best way to spread this knowledge. FrostyM288 (talk) 05:20, 16 May 2010 (UTC)
- I think that kind of material is pertinent for the Evolutionary game theory article. Sean.hoyland - talk 07:50, 16 May 2010 (UTC)
- Thanks, kept looking around and found an evolution of cooperation page that touches on some of this already. FrostyM288 (talk)
Population
The word and concept population is very important for this article. It is linked to population. But that article doesn't provide sufficient explanation for a stable understanding. The definition given in the opening sentence is true, but too short: collection of inter-breeding organisms of a particular species. I run into problems when trying to expand on gene flow. If the given definition of population were literally true, then gene flow would be analytically impossible. So somehow the the concepts of population and gene flow are depending on each other. Much gene flow -> same population; litle gene flow -> different populations. I feel a need for more discussion of this in Wikipedia, butfound myself unable to provide it. Can anyone enlighten me? --Ettrig (talk) 10:59, 17 May 2010 (UTC)
- Okay: you want pithy definitions that perfectly encapsulate a concept, but biology disagrees. What a mess. See species for comparison. This is why effective population size was invented. Graft | talk 21:41, 17 May 2010 (UTC)
- Lots of these definitions work OK with animals, stumble a bit with plants and then break down completely with microorganisms. You just have to decide what level of inaccuracy and inconvenient exceptions you can live with. Tim Vickers (talk) 22:28, 17 May 2010 (UTC)
Arrogant Text
"Evolutionary biologists document the 'fact' that evolution occurs" Like that text was not chosen to provoke responses. Interesting that lots of scientists including leading geneticists do not support evolution.—Preceding unsigned comment added by 210.56.95.225 (talk • contribs)
- Which scientists and leading geneticists do not support evolution? (Please list only those with peer-reviewed papers, please.) Mindmatrix 15:51, 1 May 2010 (UTC)
- This is
mildlyclearly discussed in the FAQ above. See it or discuss this at talkorigins. Andrew Colvin (talk) 04:45, 2 May 2010 (UTC)
- This is
Its a fact animals change over time... the 'theory of evolution' is a collection of ideas to explain the observation. Gravity's a good analogy i think. Things fall to the ground, this is a observable fact.. but the 'Theory of gravitation' seeks to explain the phenomenon. I think you confuse what is fact and theory in scientific discourse. —Preceding unsigned comment added by 139.184.30.132 (talk) 23:07, 16 May 2010 (UTC)
- Natural selection, not biological evolution, is the theoretical part of Darwin's work. PiCo (talk) 09:18, 26 May 2010 (UTC)
"Genetic" Evolution
What do you think about changing the title to "Genetic Evolution". The term "evolution" on its own just means gradual and directional change (http://www.merriam-webster.com/netdict/evolution). In the context of biology, the word "evolution" is used as shorthand for "genetic evolution", but in an encyclopaedic article I wonder if we shouldn't make the distinction between genetic evolution and other forms of evolution (some of which we have articles for here on wikipedia) such as cultural evolution, social evolution, technological evolution, the evolution of language, and the evolution of mind. I'm not trying to make a point about the importance of genetic evolution, only that it wouldn't hurt to be more specific. Gregcaletta (talk) 07:42, 14 May 2010 (UTC)
- Per WP:COMMONNAME, the "standard" name for the topic should be used, and it's pretty clear that the name is "Evolution". There are a number of other cases (which I can't think of now) where an article on a topic is given the commonly-known name, and the article starts with a referral for other usage ("This article is about evolution in biology. For other uses, see Evolution (disambiguation)". Johnuniq (talk) 10:37, 14 May 2010 (UTC)
- Yep, fair enough. We could include the term "genetic evolution" somewhere in the lede, but I've just noticed there is actually a separate article called "Genetic evolution". It doesn't actually detail a separate topic, so I'm going to suggest a merger with this one. Gregcaletta (talk) 02:57, 15 May 2010 (UTC)
- I would say the only reasonable change would be to biological evolution, and I am not suggesting we do that. Andrew Colvin (talk) 19:09, 15 May 2010 (UTC)
- I agree with Johnuniq and just see no problem here. We just need a link to a disambiguation page and anyone who comes here by mistake is two clicks away from what they want. But we have never registered many complaints by readers who meant to go to another article (Stellar evolution? Cultural evolution?) and were directed here by mistake,; I think everyone who has come here was looking for just this article. So let's not worry about hypotheticals when the system is working fine. Slrubenstein | Talk 23:43, 15 May 2010 (UTC)
I think no distinction is made in the article between Micro-evolution (variance within a species-e.g. green fish to blue fish) and Macro-evolution (change from one kind into a different kind-e.g.. fish to amphibian). There also seems to be no answer to why living fossils were not replaced by superior organisms in the path of Evolution-the problem of Convergent Evolution is not addressed-see Hoatzin and Archaeopteryx, Coelecanth, Horseshoe Crab and Trilobite. Any thoughts?--Gniniv (talk) 04:14, 24 May 2010 (UTC)
- That "microevolution is distinct from macroevolution" is claim CB902. See that page and the talk.origins macroevolution FAQ. Gabbe (talk) 04:25, 24 May 2010 (UTC)
- There's also a FAQ at the top of this page. Gabbe (talk) 04:28, 24 May 2010 (UTC)
Criticism of Evolutionary Theory
There really ought to be a section here addressing scientific objections to the evolutionary theory. I am not talking about objects from ID-proponents and other such religious fanatics. I mean, well-meaning scientific objections. I remember reading one problem with evolution being the intractability of finding a favourable mutation for a multi-cellular organism. The book 'Complexity: Emerging Science at the Edge of Order and Chaos' by M. Mitchell Waldrop cites the possibilities for algae being on the order of 10^300 (i.e. what is called an exponential problem in pure mathematics and computer science). Given such an enormous search space, the problem quickly becomes intractable. I believe there was another example where Huxley suggested 50-100 billion as the time required for life to evolve to the present state given random mutations. This info needs to be verified, of course, because I am merely recalling what I read when I was around 10-15 years old. I can't seem to find any information on any of this, any more. Back when I was in school this was a popular point of debate among evolutionary theorists. Now the objections seem to have died down. If there has been great progress in explaining these anomalies over the last few decades, then that is certainly wonderful news. Perhaps that should be more properly referred to and addressed as they were certainly problematic for evolutionary theorists of the late twentieth century. I know adding a section such as this will have all the crazed creationists crawling out of the woodwork, but if objections exist to a scientific theory, then as scientists (i.e. seekers of Truth), we cannot with good conscience ignore them. Perhaps there are editors out there familiar with objections to the theory who would care to discuss them. Rlinfinity (talk) 11:48, 25 May 2010 (UTC)
- The home for that particular argument, and many like it, is at Objections to evolution, or more specifically Hoyle's fallacy. Perhaps of more relevance here, this series examines the relationship of Darwinism and Mutationism. As an aside, nice quote on the 2nd. law . . . dave souza, talk 12:21, 25 May 2010 (UTC)
- Unfortunately you've been misinformed. I know you posted that in good faith, but the reason those objections "died down" is because they were never seriously considered in the first place, for good reason. thx1138 (talk) 12:48, 25 May 2010 (UTC)
- Evolution (the fact that animals change over time and so give rise to new species) is not a theory; the theories are about how the observed fact of evolution can be explained. PiCo (talk) 09:20, 26 May 2010 (UTC)
- Unfortunately you've been misinformed. I know you posted that in good faith, but the reason those objections "died down" is because they were never seriously considered in the first place, for good reason. thx1138 (talk) 12:48, 25 May 2010 (UTC)
- Thanks! Hoyle's Fallacy was precisely the sort of thing I was referring to. The search space being enormous is explained extremely well there. In hindsight, I suppose it should have been obvious. In the field of mathematical optimization, genetic techniques (natural selection, cross over, mutation) are used, not in spite of the enormous search space, but rather, because of it. Rlinfinity (talk) 14:39, 26 May 2010 (UTC)
- Well, there is no debate among the scientific community as to whether evolution is actually occurring, and there hasn't been any substantive debate in this vein for better than a century: the evidence for evolution is absolutely overwhelming. Certainly, there are questions that are being addressed and debated at the present regarding the construction of phylogenetic trees, especially which algorithms and which sequences are the most effective at producing reliable and consistent results. While we could include redirects to articles addressing specific, legitimate debates concerning the present models, including a section about objections would appeal to a fringe minority (within the scientific community) that historically has not had evidence to back up its assertions. —Preceding unsigned comment added by Sepia officinalis (talk • contribs) 03:59, 28 May 2010 (UTC)
- I don't know why people continue to go on about the 'fact of evolution'. That was hardly the point I originally raised. It is a self-evident fact that evolution occurred. This is known to anyone with the slightest understanding of the fossil record. I referring purely to objections on the mechanism of evolution (which the 'theory of evolution' explains), and counter-arguments dispelling those objections. Even if these objections have been discredited, there need to be reasons WHY they are discredited. Simply saying they are no longer seriously considered is not a sufficiently convincing reason for a scientist, and especially not for a mathematician. It is equivalent to saying that demonstrating the verity of the heliocentric model of the solar system is an unnecessary exercise, as the geocentric model has not been considered in hundreds of years. Still, anybody who studies mechanics beyond a secondary school level sooner or later encounters, and needs to understand, the mathematical proofs for the heliocentric model -- because by almost all empirical observations made on Earth, the geocentric model seems to be the intuitively obvious one. Similarly, if there have ever been reasonable objections to the theory of evolution, these and the arguments against them need to be properly framed. At any rate, dave souza's comment above, did exactly that by linking to these pages within wikipedia, and I see that the page is also linked in the article. Thanks for that. Rlinfinity (talk) 14:17, 30 May 2010 (UTC)
- I am confused. What non-Christian has ever used the 2nd law as a "criticism" of evolutionary theory? Or more precisely, what biologist? Certainly there was a clash between Christians and non-Christians (or, Fundamentalist Christians and non-Fundamentatalists) when Darwin first published his theory. But this is not a debate among scientists. This is not a question of a discredited theory being replaced by a newer more robust theory - this is within the realm of the history of science. This is a question about a spurious argument that has and continues to be raised by people with a non-scientific agenda (which yes can include people who have some scientific expertise), which is something else altogether. Slrubenstein | Talk 14:28, 30 May 2010 (UTC)
- Slrubenstein is right that "if there have ever been reasonable objections to the theory of evolution", which there have been, they belong in the history of evolutionary thought article and related historical articles. A quibble – when Darwin first published his theory it met with a complex response and a whole range of views, both religious and secular, as well as a range of evolutionary theories which culminated during "the eclipse of Darwinism". There have been several theories of evolution, which have largely converged as modern evolutionary theory which is described in this article. There is continuing development and debate, for example, about the relative importance of aspects such the neutral theory of molecular evolution. As for the clash between Christians and the rise of anti-evolution, that really dates from around 1920. . . dave souza, talk 16:56, 30 May 2010 (UTC)
- I am confused. What non-Christian has ever used the 2nd law as a "criticism" of evolutionary theory? Or more precisely, what biologist? Certainly there was a clash between Christians and non-Christians (or, Fundamentalist Christians and non-Fundamentatalists) when Darwin first published his theory. But this is not a debate among scientists. This is not a question of a discredited theory being replaced by a newer more robust theory - this is within the realm of the history of science. This is a question about a spurious argument that has and continues to be raised by people with a non-scientific agenda (which yes can include people who have some scientific expertise), which is something else altogether. Slrubenstein | Talk 14:28, 30 May 2010 (UTC)
In order to have scientific criticism directed towards a fact, there must be scientific criticism already out there - there are absolutely no scientific evidence to put a dent in the fact of evolution. Religious fundamentalist who attack this topic for whatever reason tends to use old-disproven theory such as abiogenesis, slow fossil record, etc that has already been scientifically tested and proven false. There won't be a criticism section in this article, because there are no credible criticism. If you want information of morality against evolution go to this site below.
http://en.wikipedia.org/wiki/Objections_to_evolution —Preceding unsigned comment added by 74.198.148.46 (talk) 14:42, 31 May 2010 (UTC)
Request
I would like to include a link to "Introduction To Evolution" at http://www.vectorsite.net/taevo.html. Consider this merely a polite request, if the answer is a simple: "No, we'd rather not." -- that isn't a hardship. MrG 67.40.35.149 (talk) 19:22, 30 May 2010 (UTC)
- Interesting link, but I believe everyone here thinks this article already has enough external links as is. See WP:EL. Gabbe (talk) 19:52, 30 May 2010 (UTC)
Like I said, not a hardship. Thanks for your time and attention. MrG 67.40.35.149 (talk) 20:04, 30 May 2010 (UTC)
Drift/Selection
Paragraph 3: "drift, an independent process"
Drift is not independent of selection as a process. Drift and selection work in tandem. Drift is the 'background' process - every life in which a particular trait makes no difference can only contribute to the random component of change in allele frequency. Where s is always 0, then every life is of this kind - all is Drift. When s is not zero, then the expectation is skewed in favour the beneficial allele - but drift can still extinguish the good and promote the bad, because:
"Genetic drift comes from the role that chance plays in whether a trait will be passed on to the next generation."
So I think 'independent' should be replaced by 'complementary', and perhaps even Drift placed first, since it is involved in the progress of all alleles, regardless of s. Selection is the interesting bit, for generation of adaptation, but drift is the default.
Allangmiller (talk) 21:01, 31 May 2010 (UTC)
- Yet, drift is independent of selection. Slrubenstein | Talk 22:02, 31 May 2010 (UTC)
- It's not independent in all aspects. See Genetic drift#Genetic drift versus natural selection, last paragraph, and its references. Narayanese (talk) 06:33, 1 June 2010 (UTC)
- That paragraph does not make clear how drift and selection are dependent processes. And I do not think that is what the sources cited are saying. Drift is just sampling error, it is a statistical phenomenon. To say that the evolution of a species involves mutation, drift, and natural selection is one thing. To say that drift depends on selection or selection depends on drift is just muddled thinking. Slrubenstein | Talk 10:27, 2 June 2010 (UTC)
Boiler plate
I move to place a more direct boiler plate at the top of this discussion page similar to the one here. It is getting quite irritating to have the constant posting of creationist crap and other personal, unscientific opinions about evolution. The notice at the head is much too soft. However, I wonder if anything will do any good? Lol! Any thoughts? Andrew Colvin | Talk 05:02, 8 June 2010 (UTC)
- Please do! Greggydude (talk) 19:36, 8 June 2010 (UTC)
- Ok! Andrew Colvin | Talk 22:42, 8 June 2010 (UTC)
- Taken care of! Andrew Colvin | Talk 22:55, 8 June 2010 (UTC)
Italics on A7
First of all, congratulations for the patience you have (as I see on a daily basis) with creationists. Fortunately on other Wikipedias we don't have this problem so often. I would like to inform that on A7 in the FAQ three species of Homo ar not italized. I don't think I can change them as this is a protected article. Cheers. -Theklan (talk) 00:59, 9 June 2010 (UTC)
- Fixed! Andrew Colvin | Talk 01:55, 9 June 2010 (UTC)
Edit request from Mthfooiut, 10 June 2010
Please add external link in "On-line lectures" section:
http://www.molbio.wisc.edu/carroll/Fittest.html "The Making of the Fittest" by Dr. Sean B. Carroll November 4, 2009 at the University of Wisconsin-Madison
Add in "introductory reading"
Carroll, S. (2006). The Making of the Fittest. New York: W.W. Norton. ISBN 0393061639.
Mthfooiut (talk) 07:56, 10 June 2010 (UTC)
Not done: please establish a consensus for this alteration before using the
{{edit semi-protected}}
template. Hidden comment on article EL section asks to seek consensus before adding more external links. I don't see a problem with the lecture, but please discuss it with the other editors before we add it. SpigotMap 12:43, 10 June 2010 (UTC)
- With the exclusion of the semiprotect, I think the lecture would be a very good addition to the online lectures section. It seems to be very informative on the article topic and adds as a great resource. I vote yes to adding it. Andrew Colvin • Talk 01:32, 11 June 2010 (UTC)
Objections to evolution Being Held Hostage.
This page is for discussing specific improvements to the "Evolution" article – not the behaviour of users on other articles nor evolution in general. See WP:TALK and WP:NOTAFORUM |
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The following discussion has been closed. Please do not modify it. |
A creationist editor has successfully convinced an admin that his views should be present on Objections to evolution and the admin has put a full protection on the page until we compromise. Currently it's a 3 day protection, but there is already talk of extending that "as long as necessary." The editor who is trying to ram creationist views into the article is Gniniv and the admin that is allowing him is SlimVirgin. We really need some additional help to get this page released from this virtual hostage situation and take care of this user. I don't think this admin is aware of the CONSENT attempts by creationists to dilute these pages or cast doubt on evolution through minor changes in wording. I thought i'd post here to see if anyone else is willing to help, or ideally an admin who follows these pages to step in and clear things up. — raeky (talk | edits) 02:46, 14 June 2010 (UTC) In the tradition of Freedom of information and the Free encyclopedia, I am trying to allow a more neutral coverage of Objections to evolution. Please feel free to contribute to our discussion at Talk: Objections to evolution How can we have an Objection to Evolution article without having any objections???? (Dude, that is wierd!)--Gniniv (talk) 03:49, 14 June 2010 (UTC)
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