One thing that has always bugged me about evolution.

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gmalivuk
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Re: One thing that has always bugged me about evolution.

Postby gmalivuk » Sun Oct 30, 2011 5:02 pm UTC

Yeah, calling it the sexy son hypothesis is probably part of the problem. Sure, it's to females' advantage if their offspring mate a lot. But in the case of elephant seals, one way this can happen is for their sons to commit a lot of rape, which isn't the same thing as being sexy.
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Re: One thing that has always bugged me about evolution.

Postby Izawwlgood » Sun Oct 30, 2011 5:09 pm UTC

Yeah, that's where part of the problem lies; 'sexy' means something a bit different in the parlance of Animal Behavior. Sexy means 'likely to be fecund', whereas for humans, it's buried under all kinds of psychosis. It is called the Sexy Son Hypothesis because it means females are going to 'choose' to mate with males that are likely to produce sons that will bear traits that other females will also 'choose' to mate with. 'Choice' is a weird way of putting it, of course; mallards, for example, are also effectively raped by males, but females are in control of their labyrinthine vagina and can reroute the males enormously inflated penis down false ends.
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Re: One thing that has always bugged me about evolution.

Postby deer_without_antlers » Sun Oct 30, 2011 9:47 pm UTC

ftfs wrote:
iChef wrote:
ftfs wrote:
Charlie! wrote:
Dr.Buck wrote:So, in that case, what would you call a deer with no antlers?

A doe?


A deer?


A female deer.


Ray, a drop of golden sun.

Me, a name I call myself?

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Re: One thing that has always bugged me about evolution.

Postby Tass » Mon Oct 31, 2011 3:13 pm UTC

deer_without_antlers wrote:
ftfs wrote:
iChef wrote:
ftfs wrote:
Charlie! wrote:
Dr.Buck wrote:So, in that case, what would you call a deer with no antlers?

A doe?


A deer?


A female deer.


Ray, a drop of golden sun.

Me, a name I call myself?

Far, a long, long way to run.

ftfs
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Re: One thing that has always bugged me about evolution.

Postby ftfs » Mon Oct 31, 2011 4:43 pm UTC

Tass wrote:
deer_without_antlers wrote:
ftfs wrote:
iChef wrote:
ftfs wrote:
Charlie! wrote:
Dr.Buck wrote:So, in that case, what would you call a deer with no antlers?

A doe?


A deer?


A female deer.


Ray, a drop of golden sun.

Me, a name I call myself?

Far, a long, long way to run.

Sew, a needle pulling thread.

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gmalivuk
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Re: One thing that has always bugged me about evolution.

Postby gmalivuk » Mon Oct 31, 2011 6:29 pm UTC

It was funny at the start...
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Re: One thing that has always bugged me about evolution.

Postby Username4242 » Mon Oct 31, 2011 7:33 pm UTC

-ish.

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Re: One thing that has always bugged me about evolution.

Postby PossibleSloth » Mon Oct 31, 2011 8:48 pm UTC

As far as sexual selection is concerned, I like the view outlined by R. A. Fisher.

In a nutshell, sexual selection begins when a female or group of females becomes genetically predisposed to find some characteristic of males attractive, meaning they are more likely to choose to mate with individuals with this characteristic.

(note: I'm using "female" and "male" here for illustrative purposes only. The two could be switched and it would make no difference to the basic idea.)

If a female has a mutation that makes her pick males with longer than average tail feathers, her offspring will carry both the gene for long tail feathers AND the gene for being attracted to long tail feathers. Basically, it creates a sub-population that will tend to mate only with members of that sub-population. Because they still tend to like longer feathers, they will keep selecting for longer and longer feathers. Given enough time, the sub-population either splits off or overruns the rest of the species.

Anyone familiar with the idea of positive feedback shouldn't be surprised that this could eventually lead to a modern peacock tail. And all that is required for the process to get started is a random push in one direction or the other.

The same principle can apply to antlers, plumage color or any number of observed traits.

Fisher actually modeled the whole thing mathematically, and contrary to popular belief, the trait DOES NOT need to be an indicator of general fitness for the model to work.

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Re: One thing that has always bugged me about evolution.

Postby Jplus » Mon Oct 31, 2011 11:28 pm UTC

PossibleSloth wrote:[...]

The same principle can apply to antlers, plumage color or any number of observed traits.

Fisher actually modeled the whole thing mathematically, and contrary to popular belief, the trait DOES NOT need to be an indicator of general fitness for the model to work.
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