sexual dimorphism in ungulates

[G W]

what are the advantages of evolving distinctive sexual dimorphism in the ungulates? For example male and female Nyalas are very differnt, but in some other ungulate species the male and females took very similar?

[iNow]

What do YOU think?

[Darwinsbulldog]

what are the advantages of evolving distinctive sexual dimorphism in the ungulates? For example male and female Nyalas are very differnt, but in some other ungulate species the male and females took very similar?

Males and females have different "interests" [or at least their genes do]. But they are obliged to cooperate because they share a common genetic destiny. That is, they have to cooperate to reproduce. But nevertheless things can go haywire. Like segregation distortion. [Meiotic drive]. So basically, an mutation can act to reduce the fitness of the other sex. If it goes too far, then the species can go extinct.

 

But you were talking about sexual dimorphism. That is usualy caused by male-male competition. [eg Irish Elk or seals] or female choice [peacock's tails].

 

Interestingly, in mammals the male SRY gene is able to produce modular changes via interacting with gene regulatory networks, especially Hox. This interaction between sex determination pathways and developmental pathways can also work in insects, or any bilateral metazoa really. This is why male dung beetles can have huge horns, and females small ones.

[skyhook]

what are the advantages of evolving distinctive sexual dimorphism in the ungulates? For example male and female Nyalas are very differnt, but in some other ungulate species the male and females took very similar?

 

This could be due to sexual selection as said by Darwin, but some consider it the same as natural selection. Nyala, this antelope has horns, the females probably don't have, and the males are larger size. The horns may be used for display to intimidate other males, a larger pair of horns look more impressive. When it comes to real fight, bigger horns and bigger body usually wins. so the winner gets to mate. The advantage for the males would be it get to propagate more often.

Many of the other ungulates shows sexual dimorphism, some species show more difference, while some show less difference.

Edited October 9, 2010 by skyhook