[ExI] IQ and beauty

[Dan TheBookMan]

On Wed, Oct 7, 2015 at 10:39 AM, John Clark <johnkclark at gmail.com> wrote:
>
> On Wed, Oct 7, 2015 at 11:24 AM, Dan TheBookMan <danust2012 at gmail.com>
wrote:
>
>> >
>> My guess regarding detection mechanisms is these are imperfect too.
>
> Yes certainly.

I wanted to be annoyingly clear on that. :)

> A particular trait is determined by a gene

Well, an issue here is whether the particular trait or set of traits is
determined by a gene or set of genes in the first place. Imagine this
instead. The detection mechanism itself is wide-ranging. It's not a general
beauty detector or even a specific-trait detector. It's simply a detector
with many capabilities. (Not saying it's omni-capable here -- just that,
for humans, it might not be something like a red-dress detector or even a
color-red detector.) Then maybe early imprinting (or memory associations --
or whatever is not under direct genetic control here) simply tunes the
detector for red dresses or the color red -- or for long straight black
hair as opposed to curly auburn hair with blond highlights. (Presuming
these latter are under more or less direct genetic control and easily
selected for in an actual population -- as opposed to merely in the lab or
merely in an idealized mathematical model.)

Granted, if enough members of the population are tuned for curly auburn
hair with blond highlights, then it might look like the mechanism is being
selected for and the overall effect looks like sexual selection. (Let's
assume that the detectors themselves are selected for by other things, such
as being good at seeing colors overall is simply better for overall
survival regardless of mate selection.)

All this stuff would have to be confirmed for each trait too -- not just
presumed because it makes a good story. (Beware the evolutionary just so
stories as someone once warned here. With the example you're using, for
instance, see http://www.nature.com/news/2011/110418/full/news.2011.245.html
Kind of shows that empirical studies need to be done and alternatives
considered before rushing to judgment, no?)

> and the fondness a animal has
> for that trait is also determined by a gene, usually a different gene;
and both genes are
> under Evolutionary pressure.  The female needs a rule of thumb to choose
which male
> to mate with,  but that rule of thumb could turn out to be a bad one.  A
bird species
> with a very small tail can't fly very well so a gene that said "mate with
a male with a
> bigger tail" would be a good rule of thumb, but as the generations went
by and the tail
> got bigger and bigger it would start to get too big and if that rule of
thumb is not modified
> it could lead to trouble as in the peacock. If the gene for having a big
tail and the gene
> for preferring a big tail were the same or if the 2 genes were close
together on the
> chromosome and thus usually inherited together then the possibility of a
disastrous
> positive feedback loop would increase.
>
> A mutant bird with a smaller more aerodynamic tail would probably live
longer because
> he would be better at getting food and avoiding predators, but fewer of
his genes would
> get into the next generation because he would have trouble finding a mate.

That's the typical tale :) with peafowl. Not sure how well it's been tested
or whether it's a disaster. What I've heard used as an explanation is
having a outsized tail and living is kind of proof to the peahen that the
peacock is fit overall because a less overall fit male with the same large
tail would likely end up as dinner or otherwise in dire straits.

Regards,

Dan
  Sample my Kindle books via:
http://www.amazon.com/Dan-Ust/e/B00J6HPX8M/
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