Pinball1970
Valued Senior Member
The handicap principle
- Thread starter Spathi
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Pinball1970
Valued Senior Member
The edition won't post but the key point did eventually. See above
exchemist
Valued Senior Member
These pages (I had to load copy and store them as images so I could rotate them to read them) seem to be just a description of the handicap principle. I saw no comment on whether Dawkins thinks it is valid.
Handicap principle - Wikipedia
en.wikipedia.org
- "In the classic handicap models of begging in game theory, all players are assumed to pay the same amount to produce a signal of a given level of intensity, but differ in the relative value of eliciting the desired response (donation) from the receiver. The hungrier the baby bird, the more food is of value to it, and the higher the optimal signalling level (the louder its chirping)."
Due to that, even a human can hear in the distance when a northern cardinal has a stealthy, alien invader living amongst its offspring. Yet somehow the cowbirds and their multiple hosts find a middle line and stay in business over the millennia, neither going extinct as the result of the negative, one-way interdependency.
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Okay, here's another citation of the text just after the citation made by me and Pinball1970 (again, my citation is in an autotranslation). Here is the phrase I mentioned below, like "the reality can be truly insane":
Pinball1970
Valued Senior Member
He said it could become an ESS, exist in nature. I'll try and scan in another page after work.
Images is a pain on this device.
exchemist
Valued Senior Member
What's an ESS?
Pinball1970
Valued Senior Member
Evolutionary Stable Strategy, John Maynard Smith analysis of different genetic combinations in populations.
Scanned text are hard to read. Maybe my citation above is sufficient? Dawkins wrote that he understood that the "common sense" can be wrong, "insane" theories can be true and this is even nerving. This is what I tried to explain in this thread.
TheVat
Valued Senior Member
The chat over at Dot Net may be helpful in getting through some of the conceptual challenges of honest signalling, finding optimal balance between costs of display and viability, etc.
www.scienceforums.net
(I don't want to paste in everything Seth, Charon, and I wrote over there)
Basically, the theories move now towards seeing that equilibrium between display costs (metabolic, hazard, social, etc) and viability are not necessarily about waste. Index signalling, for example, is not wasteful, since it comes from basic physiology and morphology of the animal and not conspicuous and expensive alterations during mating season. Stotting gazelles can jump high because they are built for it and it's useful for seeing farther around them and a side benefit of having powerful legs. It doesn't drain their metabolic funds or incur other costs. It's an honest display of vigor, also can be adapted for courtship displays. Natural selection will tend more towards stotters than peacocks with pounds of arse plumage. Handicapping is atypical because natural selection pressures towards overall viability in environments that are unforgiving of over-investment in flashy bling.
The handicap principle
www.scienceforums.net
(I don't want to paste in everything Seth, Charon, and I wrote over there)
Basically, the theories move now towards seeing that equilibrium between display costs (metabolic, hazard, social, etc) and viability are not necessarily about waste. Index signalling, for example, is not wasteful, since it comes from basic physiology and morphology of the animal and not conspicuous and expensive alterations during mating season. Stotting gazelles can jump high because they are built for it and it's useful for seeing farther around them and a side benefit of having powerful legs. It doesn't drain their metabolic funds or incur other costs. It's an honest display of vigor, also can be adapted for courtship displays. Natural selection will tend more towards stotters than peacocks with pounds of arse plumage. Handicapping is atypical because natural selection pressures towards overall viability in environments that are unforgiving of over-investment in flashy bling.
exchemist
Valued Senior Member
Well that makes sense but doesn't account for why these instances of flashy bling do nevertheless occasionally arise, which is presumably what the Handicap hypothesis was intended to explain. So what is now the accepted explanation for those? Is it just like genetic drift, i.e. something that rises by accident and is tolerated by natural selection if it does not unduly impede breeding success?The chat over at Dot Net may be helpful in getting through some of the conceptual challenges of honest signalling, finding optimal balance between costs of display and viability, etc.
The handicap principle
(I don't want to paste in everything Seth, Charon, and I wrote over there)
Basically, the theories move now towards seeing that equilibrium between display costs (metabolic, hazard, social, etc) and viability are not necessarily about waste. Index signalling, for example, is not wasteful, since it comes from basic physiology and morphology of the animal and not conspicuous and expensive alterations during mating season. Stotting gazelles can jump high because they are built for it and it's useful for seeing farther around them and a side benefit of having powerful legs. It doesn't drain their metabolic funds or incur other costs. It's an honest display of vigor, also can be adapted for courtship displays. Natural selection will tend more towards stotters than peacocks with pounds of arse plumage. Handicapping is atypical because natural selection pressures towards overall viability in environments that are unforgiving of over-investment in flashy bling.
I can imagine there could be irrelevant features that happen to appeal aesthetically to females, due to some side effect of how their brains are wired, which won't be weeded out by natural selection so long as (1) the males live long enough to impregnate the females and (2) the males are not required to take part in rearing the young after mating - or are not impeded by the feature in question in doing so.
Pinball1970
Valued Senior Member
I would have to flatten the book and damage the pristine spine.
TheVat
Valued Senior Member
Yes, males in species that practice, say, brood parasitism are going to have more leeway to wear themselves out in courting behavior and mating. So maybe they can drift into more extravagant investments which reduce their own viability, while still edging out weaker males. "Drift" might not be inaccurate in that it's tolerated by NS where over-investment doesn't affect an ecosystem by reducing overall food supply or disrupting communication networks, etc. Interesting point about how female aesthetics can shift in ways that are selectively neutral (while presumably attraction is still anchored in primary index signals of health and strength....a female could see two males who can both lift 15 pounds of tail feathers off the ground and know both are strong, but then pick one on the basis of a gaudier purple bib).
Now I’ve been thinking that perhaps the Handicap Principle isn't actually so counter-intuitive as it can look like. A question for those familiar with Grafen’s experiment: am I right that the "handicaps" (inherently disadvantageous traits that help a male attract females precisely because they are disadvantageous) are exclusively male traits that aren't passed on to female offspring?
In humans, for instance, these would be traits encoded on the Y chromosome, which women lack. That makes the whole subject seem more or less clear. Suppose a man has a enormous ..., so large that it actually harms him and hinders his survival. A woman considering him as a potential father for her future children knows that if they have daughters, those daughters won't inherit this disadvantaguos trait; instead, they’ll inherit the man's other genes, i.e. the ones that allowed him to survive despite this problem. It’s trickier with sons, but there’s another factor at play: if conditions for the population turn bad and 90% of the males die, nobody really cares, because the remaining 10% will be still able to impregnate all the females and pass them their good genes. I think I understand it a bit better now.
But this means that Dawkins was talking nonsense in the final sentence of the last quote above (signal of an animal to a lion) that’s not exactly how it works.
In humans, for instance, these would be traits encoded on the Y chromosome, which women lack. That makes the whole subject seem more or less clear. Suppose a man has a enormous ..., so large that it actually harms him and hinders his survival. A woman considering him as a potential father for her future children knows that if they have daughters, those daughters won't inherit this disadvantaguos trait; instead, they’ll inherit the man's other genes, i.e. the ones that allowed him to survive despite this problem. It’s trickier with sons, but there’s another factor at play: if conditions for the population turn bad and 90% of the males die, nobody really cares, because the remaining 10% will be still able to impregnate all the females and pass them their good genes. I think I understand it a bit better now.
But this means that Dawkins was talking nonsense in the final sentence of the last quote above (signal of an animal to a lion) that’s not exactly how it works.
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Pinball1970
Valued Senior Member
TheVat
Valued Senior Member
No. And most genes do not express as simple specific phenotypic traits. For example, male baldness is mediated by over 250 gene loci and most of them are autosomal.
I suppose, this is of no importance? For example, there is no single gene defining the size of ... for men, but anyway all the genes which define it, are located in Y chromosome.
Pinball1970
Valued Senior Member
Already said there are few genes that would contribute to a trait on that Chromosome.
exchemist
Valued Senior Member
No. You are missing the point. The main function of the Y chromosome is to switch on a whole series of other genes, related to male characteristics, that are located elsewhere.
I have a feeling that perhaps the handicap principle is actually not more strange and counterintuitive, than the concept of nagware in IT, which is very familiar to me since I am a programmer. Nagware is the way of distribution of software, when you download a free version of a program, and it's usable and has full functionality, but an annoying window constantly pops up where you have to enter a captcha. To make this window disappear, you have to pay money for authors. In my opinion, this is, in many cases, much better than traditional adware (when the free version shows you ads).
So maybe nagware is actually a fairly close and accurate analogy to handicap?
Anyway, one of the main factors in evolution is that even a small number of males can fertilize all the females in a population, so the death of a male is not a serious threat to the population. The moral of the story: take care of the women (not the men).
So maybe nagware is actually a fairly close and accurate analogy to handicap?
Anyway, one of the main factors in evolution is that even a small number of males can fertilize all the females in a population, so the death of a male is not a serious threat to the population. The moral of the story: take care of the women (not the men).