Sex ratio constant

[yayacatfight]

Hi everyone,

I think I remember reading that attempts to breed biases in the sex ratio have always failed. That is, you can breed pigeons with long tails or mice with big ears, but you can't breed any animal to produce more males than females.

Is this correct?

Thanks

 

[iceaura]

Lots of insects, fish, reptiles, etc, breed naturally high biases - usually female, though.

Are you asking whether you can breed for male bias in a population of mammals or birds, specifically ?

 

[yayacatfight]

Yes, sorry, a naturally occurring bias in for example, ants, I understand how that makes sense and comes about naturally.

But for mammals or birds where one male and one female mate to reproduce, is it true that it is impossible to breed a strain that has a sex ratio bias?

I believe it was in Origin of Species in which I read that repeated attempts to do this in pigeons failed, whereas every other experiment, short beak, long beaks, long tails, color, feet size, etc etc, could eventually be manipulated.