ANTHRBIO 201 1st Edition Lecture 13Primate Mating: Sexual SelectionThe peacock’s tail the sight of a feather in a peacock’s tail makes me sick - Darwin trail of feathers may hinder their survival sees the male mandrill’s face (similar, bright structure to peacock feathers) as if his face alerts his predators of his presence also proboscis monkey’s nose male orangutan’s cheek pads problem: the existence of structures that have no clear bearing on helping an organism survive devises secondary theory of sexual selectionSexual selection: a definition effects of a struggle between the individuals of one sex, generally the males, for possession of the other sex types of sexual selection Intrasexual selection- within the sexes favors the ability of one sex to compete directly with one another for fertilizations by fighting intersexual selection between the sexes favors traits in one sex which attract the other; uses these traits to pick one mate over the other “female mate choice” IV. Parental investment and sexual selectionsex differences in reproduction Redtail monkeys mating and reproductive behavior number of kids producedgreater variability in male reproductive performance than female Kipsigis 6 differences in reproduction maximum # of offspring produced during lifetime Males=888 emperor of Morocco females=69 during 27 pregnancies sex differences in parental investment females invest in the reproductive process far more than male female gestate females lactate females carry infants induces males to scramble around and compete amongst themselves for the limited number of females who are out therewhere one sex invests considerably more than the other, members of the latter will compete among themselves to mate with members of the former Sexual dimorphism in body size A. males are much bigger than females size is a competitive advantage in sexual selection and favors males who are bigger Prof. vs professional football player VI. Types of female choice- intersexuallydirect material benefits- good resources resources the males provide male protection against aggression indirect material benefits- good genes non adaptive traits, arbitrary, aesthetic traits male proboscis monkey