how did the peacock's handicap arise?

[gusl]

A- Why do peacocks have huge tails?
B- Because peahens find them attractive.
A- and why do they?
B- because it's a handicap: any peacock that survives with such a ridiculously long tail must be pretty fit otherwise. His genes must be good.
A(1)- well, why do we care about "otherwise"? It's not like the peacock can chuck his tail when he's in danger, so any kids coming out of this mate will suffer all the same negative effects of this handicap. Are these females just hoping that future females will find their kids attractive for no good reason too? Are they betting on the Equal Fool Theory?
B(1)- there are probably mathematical principles (as well as empirical evidence) explaining why a peacock with such a handicap is still fitter than one without one.
A(2)- So the purpose of the tail is to impress females, right? Well, this seems to answer all of our questions, doesn't it? The problem is that this is a case of co-evolution: how did the peahens come to find long tails attractive in the first place? It's not like they could reason "well, if he has such a large handicap, then he must be good to mate with!". Attraction doesn't involve logical reasoning*: it is hard-coded genetically! So it would require an enormous coincidence for the long-tail mutation to come at the same time as the long-tails-are-attractive mutation in a large enough number of individuals simultaneously.
B(2) - Larry Gonick to the rescue!

(in case the link breaks, the answer is: learning biases in neural networks. A NN trained to identify "male" will respond more strongly to huge tails.)

(*) it is interesting to think about whether and how logical reasoning affects. In human, such reasoning processes can definitely affect attraction. Maybe this is due to our strong ability to imagine.

Comments

[trufflesniffer.livejournal.com]

I guess that means we're not the only species which act 'irrationally' due to our reliance on heuristics. What I read about the Handicap Principle never quite made sense to me. This would make the situation similar to that of the baby birds which opens its mouth and begs for food when it sees a certain shape which it associates with its mother, and certain shapes/patterns can be made which seem more like a 'mother' than the actual 'mother', and thus elicit a stronger reaction in the baby. (Another example is the representation of women in cartoons with physically impossible hip/waist ratios, I think.)

[gustavolacerda.livejournal.com]

... or *actual* women with abnormally high WH ratios, like supermodels. They're slightly abnormal, and probably less fit, except sexually, of course.

[gustavolacerda.livejournal.com]

and by "high", I mean "low", of course.

[trufflesniffer.livejournal.com]

There's something similar going on with female facial proportions (as an indicator of hormone levels): extra-small jaws, which are mechanically a 'problem', are considered extra attractive, I think.

[gustavolacerda.livejournal.com]

I am attracted to ladies with very large eyes. This would normally mark youthfulness, but when I stop and contemplate these hotties objectively, I may notice that their proportions are as absurd as cartoons.

While we're on the topic

[trufflesniffer.livejournal.com]

I just saw this article in New Scientist.

Re: While we're on the topic

[gustavolacerda.livejournal.com]

I think this applies to females too, e.g. breasts, probably butt size too. But these two are a bit more complex, because they are also related to body fat.