Talk:2R hypothesis

A fact from 2R hypothesis appeared on Wikipedia's Main Page in the Did you know column on 30 August 2007. The text of the entry was as follows:

Did you know... that according to the 2R hypothesis, the genomes of modern vertebrates are the result of two rounds of genome duplication hundreds of millions of years ago?

A record of the entry may be seen at Wikipedia:Recent additions/2007/August.

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Molecular Biology: Genetics / COMPBIO

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Suggestions for improvement[edit]

I'm noticing a number of things in this article that could use improvement.

The name "2R hypothesis" is becoming obsolete. It is now more widely referred to as "two rounds of whole-genome duplication" or "2R-WGD" for short. It is also referred to as an event more often than a hypothesis. The material in the lede regarding the origin of the term would be more appropriate in a separate etymology section, since it detracts from the substance, only the term is no longer sufficiently notable to warrant an etymology section. Maybe it should just be deleted as cruft.

In the lede it says, "Variations in the number and timings of genome duplications typically still are referred to as examples of the 2R hypothesis." I couldn't find this in the antiquated source, but it is patently absurd. Whole genome duplications are a basic fact of evolutionary biology. 2R has no variation in number: it's exactly 2. A third event in vertebrates, known as 3R, occurred in stem-teleosts. That one is often discussed as an extension of 2R, but that's a separate subject. As for the timing, everyone agrees that hagfish and lampreys inherited ohnologs from 2R and that lancelets and tunicates did not. Thus, it was somewhere around the first vertebrate. Obviously you can't put a date on this in calendar years, but that's a separate issue.

Next, there is a consensus that whole-genome duplications are generally followed by periods of rapid gene loss. The genes that remain typically belong to vast gene-complexes scattered across the genome, usually no more than a handful. For example, only about 20-35% of the genes in the human genome are 2R ohnologs, but they all belong to such vast complexes.

Next, 2R ohnologs in the human genome are prone to dominant deleterious mutations and frequently implicated in cancer and genetic diseases. There is a large body of research on this.

The body of the article is currently divided into two sections, "Ohno's argument" and "Later evidence." These should be lumped into one section entitled "History." Once we have more material to round out the article, the History section should be greatly reduced. Zyxwv99 (talk) 00:15, 22 December 2015 (UTC)[reply]