TheDevilsAdvokaat t1_j9j3lgp wrote
Reply to comment by CletusDSpuckler in What are more accepted hypotheses that similarly explain the aspects of hominid evolution that the "pseudoscientific" aquatic ape theory does? by KEVLAR60442
Sometimes things we think are weird quirks actually have benefits we just haven't realised.
There's a severe cost for females having babies with older males. It's well known that over a certain age, babies from older men have increased problems.
As the father grows older, the number of mutations in the father's genome increases, leading to an increase in the incidence of congenital malformations in offspring [11, 65]. Older paternal age may be harmful to the offspring's health in terms of genetic mutations, telomere length, and epigenetics
But how do you easily tell or estimate a male's age? Well, what about a signal like graying? Imagine if there was a signal that was almost universal among males, easy to spot at a glance, and a decent general guide to age?
I suspect graying is NOT a "weird quirk". It's just one we didn't realise the benefit of. There could be other good reasons for graying too. Graying may be an "honest signal" like stotting.
https://en.wikipedia.org/wiki/Signalling_theory#Honest_signals
I suspect there are a lot less "weird quirks" than people think; just misunderstood adaptations.
F0sh t1_j9jegz2 wrote
It's advantageous to be able to identify less fit mates, but it's advantageous to look like a fit mate whether you are or not. It's difficult to have honest signals which aren't difficult to fake; you can't stot unless you're fit, you can't make an alarm call only when there are predators around unless you can detect the predator. If grey hair is energetically no more or less favourable than coloured hair then it would be difficult for it to spread as an honest signal of unfitness because it could just as easily be faked.
It seems more likely that grey hair is a signal for something else - age and hence some kind of experience/authority, or a side-effect of something else. Testosterone has a lot of effects, it probably has some that weren't specifically selected for.
TheDevilsAdvokaat t1_j9jgso6 wrote
>If grey hair is energetically no more or less favourable than coloured hair then it would be difficult for it to spread as an honest signal of unfitness because it could just as easily be faked.
You're right. It's not an honest signal, because it can be faked.
However, while it's advantageous for individuals to fake, it's disadvantageous for the populations that contain individuals that fake.....so there's pressure to fake and pressure not to fake. Overall I would guess the pressure not to fake would outweigh the individual pressure to fake but it is just a guess...
>It seems more likely that grey hair is a signal for something else - age and hence some kind of experience/authority, or a side-effect of something else."
I agree. I showed a possible reason for gray hair, I am sure there are others. ANd in reality the total advantages for grey hair are going to be a SUM of the advantages and disadvantages. Whether that sum is a total positive or negative, who knows; the sign (+ or -) will probably differ depending on whether we're talking individual advantages or population advantages.
Which leads back to my original point; that some of the adaptations dismissed as "quirks" probably aren't.
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