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Go to: A misguided attack on kin selection

vanghelie's Avatar Jump to comment 16 by vanghelie

If the ants had already evolved the sterile worker-caste system

Isn't this where we started from? We are talking about "phenotypes that are never expressed in reproductive individuals" so sterile workers must already be in the picture..

Ok so with C=0, the equation basically says "a trait can develop if it has a positive influence on the queen". Duh, that's a triviality.

Note that you can make an equation like "rB > C" always hold in any case by just making up values for B or C; I don't see the insight that gives you in cases like this where it resolves to a triviality like "B > 0".

More specifically, I don't understand how this relates to:

'Colony selection' and 'superorganisms' don't do the trick. You have to talk about shared genes in individuals, with conditional phenotypic expression.

I don't see what insight brought by Hamilton's rule "does the trick". It seems we are simply saying what 'colony selection'/'superorganism' says as well - the positive benefit to the queen is what matters.

Updated: Tue, 31 Aug 2010 17:50:33 UTC | #508741

Go to: A misguided attack on kin selection

vanghelie's Avatar Jump to comment 14 by vanghelie

s.k.graham,

Thank you for your reply.

I'm sorry to say I am still very confused.

In the first paragraph you explain Hamilton's rule.

Most of the second paragraph is clear:

The genes for soldiers jaws and honeypots can only have been passed on through queens that were related to the soldiers and honeypots. The were favored by natural selection because these traits in the workers helped the queen reproduce. The queen never has the soldier jaws or honeypot abdomen, so those traits did not directly help her reproduce, those traits only help her because they help her workers to help her. Her workers are her kin.

Of course the genes could only have mattered if the soldiers are related to her.

Hence kin selection (reproductive success of the queen, who is kin to her workers) is the natural selection mechanism that favored the soldiers jaw and honeypots ant's abdomen.

This final conclusion is what really doesn't help me at all. Read superficially, it seems obviously true. But after having explained Hamilton's rule as part of 'defining' kin selection, are you suggesting that this rule is relevant here? If yes, why? (that is what I was and am asking)

Here is my specific problem:

If gene A in some way makes you sacrifice time/energy/resources so that you have less chance of producing offspring yourself, but you increase the chance of someone (or several someones) related to you having offspring, then the "loss" to gene A in not being pass on in your own offspring may be offset by the gain in its chances of being passed on in the offspring of your relatives.

How can something like this be relevant here? Who is sacrificing something so that IT has less chance of producing offspring? The gene results in some workers sacrificing something for other workers and (directly or indirectly) the welfare of the queen - but they have 0 (or very little) chance of producing offspring anyway. As far as the queen is concerned (which is the only reproducing agent here), the gene only results in an increase of effectiveness of how she is "cared for" (regardless if some workers suffer for others because of it..)

Tue, 31 Aug 2010 13:50:07 UTC | #508545

Go to: A misguided attack on kin selection

vanghelie's Avatar Jump to comment 5 by vanghelie

Hi,

I find this intriguing:

"Alex Kacelnik points out to me that kin selection is the only way in which worker adaptations such as soldier jaws and honeypot abdomens – phenotypes that are never expressed in reproductive individuals – could have evolved. 'Colony selection' and 'superorganisms' don't do the trick. You have to talk about shared genes in individuals, with conditional phenotypic expression."

Can someone who understands this expand a bit and explain (to a layman) how kin selection explains the evolution of these traits?

The way I see it, something like "individuals who share this gene cooperate more" does not make sense as the individuals themselves do not reproduce; the only relevant consequence of their cooperation (or lack there of) is how well they can "help" the queen reproduce.

Mon, 30 Aug 2010 22:51:15 UTC | #508268

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