bugs have a fascinating version of "BP" and it is useful too. i can't think of any off the top of my head but i'm sure they exist. i can say, with no proof at all- just guessing, that humans do. there are more females than males, so males would be the selecting sex. plus females of this species peacock themselves to attract mates. i'll consult the literature and get back to this.
yes, thanks for that. but, I think that it's not the number of individuals that make for the selecting sex, but the cost of reproducing. females have a much higher cost of reproduction, in humans, and AFAIK other mammals. It is the differential cost of reproduction that allowed sexual selection to evolve. Sperm is cheap and the reproductive strategy that works best is to spread it around to as many different mates as one can. eggs are expensive, add on the child rearing, breast feeding (in mammals) etc. makes reproduction even more costly.
