... for the birds? Peacockery.
I think that natural selection plays a major role in the origin and development of species, but I doubt if it comes near to telling the whole story. And isn't that the problem in debates like this, the presumption that there is a simple, one-size-fits-all explanation of reality?
By the bye, mention of peacocks always brings to my mind that line in Wallace Steven's "Domination of Black," "And I remembered the cry of the peacocks," which meant a good deal more to me after I heard what a ghastly sound that cry is.