Talk:Defence mechanism (biology)

Merge?

I hadn't noted the existence of this article. It's very similar to antipredator adaptation, and should probably be merged with it. There are two issues: firstly, plants might not be considered 'prey' in the narrow sense. I don't think is a good way to treat the subject, and would recommend treating all organisms eaten by an animal as prey. Secondly, defense could also include defense against conspecifics, for example, such as mimicry in females to avoid sexual harrassment. Finally, parasites, grazers and parasitoids can also be considered predators in the loosest definition of the word, so they could be treated here too potentially. Either it should be merged or tidied up and kept as a summary of other more specific articles. The fact that it doesn't say what it's about to begin with is a bit annoying. Richard001 05:28, 8 October 2007 (UTC)

About plant defences, there is already an articles dedicate on the subject, Plant defense against herbivory, which has plenty information. I believe merging would not be a problem. leonardorejorge 18:58, 25 October 2007 (UTC)

"see also" is better

I feel that it would be more beneficial to simply add reciprocal "see also" pages. Though they may have similar material presently, they may branch out into two very distict pages in the future, as "anitpredator adaptation" is a fairly specific term and "defense mechanism (biology)" is more general.Triumbrum (talk) 13:29, 22 November 2007 (UTC)

Comment

Both articles are pretty rubbishy at present, but the topic is important. Triumbrum's point is good, but 'see also' between two poor articles does not do it for me.

'Defence mechanisms' should be broad and inclusive; 'anti-parasite', 'anti-herbivore' (here Plant defence against herbivory is good and removes the need for us to treat it in detail) and 'anti-predator' are possible sub-pages. (Note William Hamilton's point that large animals predominantly suffer diseases and parasites, whereas small animals suffer predation)

If we want to do this we'll need a small team! I'm prepared to sketch out a syllabus for defence mechanisms for your (collective) review and editing. RSVP! Macdonald-ross (talk) 06:27, 14 May 2008 (UTC)

I would merge, and leave Defence mechanism (biology) as a redirect to Defence mechanism (which in my opinion should be a disambig page). --Una Smith (talk) 15:11, 1 June 2008 (UTC)

We have something of an hierarchy:

Defence mechanisms

——— 1 Defence mechanisms (biology)

——— 2 Defence mechanisms (psychology)

——— 3 Defence mechanisms (other)

and then

1 Defence mechanisms (biology)

——— 1.1 Defence against herbivory

——— 1.2 Defence against predators

——— 1.3 Defence against conspecifics &c.

——— 1.4 Defence against parasitism & infection

and then

1.2 Defence against predators

——— 1.2.1 Armour

——— 1.2.2 Camouflage

——— 1.2.3 Aposematic / distasteful

——— 1.2.4 Mimicry

——— 1.2.5 Flight & other behaviour

So, a disambig page will be needed, but it won't by itself solve the problems posed by the biology content. Also, I think Defence (biology) is needed to explain, at a simple level, the huge range of adaptations that exist, and direct to other pages as required. Anyway, my view is that these topics shouldn't grow like Topsy; some kind of agreement is needed before we devote more time to this area. Some sub-topics like mimicry are already fairly well treated, of course: they just need to be brought into a broader picture. Macdonald-ross (talk) 06:52, 3 June 2008 (UTC)

Overvew, continued

It's good to see how others have tackled this area. Malcolm Edmunds in Defence in animals, Pergamon 1974, tackled predator-prey defences, but not defences against infection and parasitism. The arrangement went like this:

Primary defences: function: to decrease chance of encounter.

definition 1. Operates before predator takes any action (action = prey-catching behaviour). Robinson 1969.

definition 2. Operates regardless of whether predator is in the vicinity. Kruuk 1972, and Edwards.

1 Prey may not be detected.

1.1 Anachoresis; lives in holes &c.

1.2 Crypsis

2 Prey detected, but not seen as edible

2.1 Aposematicism

2.2 Batesian mimicry

Secondary defences: function: to increase chances of prey surviving encounter. These defences may operate as soon as prey detects predator, or after predator has started a prey-capture attempt.

1 Passive measures: armour, chemical defences

2 Active measures

2.1 enhanced primary defence

2.2 other:

withdraw to a fastness; flight; deimatic behaviour (startle or threat display); thanatosis (feining death); deflection (diversion behaviour, deflection marks, detachment of body parts); retaliation

Defensive groups including mixtures of species

The evolution of defensive systems

Ruxton, Sherratt and Speed wrote Avoiding Attack: the evolutionary ecology of crypsis, warning signals and mimicry, Oxford 2004. Their canvas is slightly more restricted than Edmunds, but they do cover the experimental literature thoroughly.

Both books are first-class, and both leave out (as perhaps we might) infection and parasitism. Macdonald-ross (talk) 09:11, 4 June 2008 (UTC)