LIFESCI 15 Lecture Notes - Lecture 13: Male Reproductive System, Standard Deviation, Sex Steroid
Document Summary
Females = better @ object memory math calculations. Stimulate growth & maintain of male reproductive system. Stimulate sex characters: hair growth, low voice, muscle mass. Song birds mating increased testosterone = increased reproductive success & higher mortality. Inject birds with extra testosterone: birds more aggressive/ smaller birds fought longer for better territory, smaller birds would get better territory & reproduced more, birds lost feathers & had lots of scabs = high mortality. Rat maze learning: males better than females only during high testosterone season, more t = better learning. Chess/tennis battles: prior: both guys" t rises, after: loser"s decreased, winner increased & stayed high. Thm #1: sex differences in behavior are strongly influenced by gonadal hormones. Thm #2: early nurturing of the child/embryo is necessarily female dominated. (especially in mammals) Thm #3: after the first mating, additional matings are valuable to males but not very valuable to females.
