Expert: Walter Hintz - 10/30/2010

Question
Hi,

I should've asked this question in the "evolution" section
but currently that section has no experts.

Anyway, I was reading this book called "A very short
introduction to: Evolution - By : Brian and Deborah
Charlesworth".

Under the section of Sexual selection, the authors argue
that all selection need not be beneficial for the survival
of the species.

For example, they talk of how competition amongst males in
various species leads to the males developing
characteristics that may help them attract females, but
these characteristics may not necessarily be beneficial in
the survival of their species or their ownselves.

For example, male peacocks have larger tails to attract
females even though larger tails hinder flying and escaping
hunters.

My Question is :

Why do females feel attracted by such characteristics (ex. a
long tail in birds) which are not beneficial in the survival
of their species?
Or in other words, why isn't this "sexual competition
between males" based on characteristics that better the
chances of survival ?

Why is sexual selection so opposed to natural selection that
works on the priciple of chances of better survival ?

Thank You

Answer
First of all sexual selection is a form of natural selection. I do not see the authors point here. If a trait (Such as a larger tail) appears them the male will not mate and suffer genetic death when that gene is not passed on.
In evolutionary biology things are as they are because that is what works best. If the tails that the  peacocks have were not the best suited for them they would not be like that