ANT 1 Lecture 8: Lecture 8
Document Summary
Intersexual selection: favors traits that make one sex (usually male) more attractive to other. Phenotypic benefits: traits affecting female survival, offspring survival. Phenotypic benefits: protective ability, resources, social support. Genotypic benefits: genetic quality -> color, display condition. Costly signals: only the males with good genetic qualities (good immune system, strength to escape predators) could afford these. Arbitrary traits: female preference develops by chance. Survival advantage -> female preference -> runaway sexual selection. Favors traits that make individuals successful in competition with others of the same sex. Contest competition: males increase mating success by preventing other males from mating. Larger body size, weapons, costly signals, aggression. If males can"t control territories with multiple females & infants need parental investment from one or more parents. 1 adult female, 1 adult male (pair living) Parental care more profitable; increases rate of survival. If multiple adult females can aggregate & infants don"t need parental investment.
