LIFESCI 15 Lecture Notes - Lecture 13: Master Sergeant, Standard Deviation, Lactation
Document Summary
Early nurturing of the child/embryo is necessarily female dominated (esp. in mammals). After the first mating, additional matings are valuable to males but not very valuable to females. In which sex is variance in rs greatest: for males and for females there is a mean and standard deviation of r. s, the mean is the same (why?, the standard deviation is not (why?) Case studies variance in male reproductive success. December: males fight to control beach, go without food until march, establish dominance hierarchy. Top 4% get 85% of the copulations (may have 50-200 babies in one year) Economics 101: those who have valuable resources don"t give them away. Because female reproductive investment is initially higher, they are vulnerable early on. We expect the evolution of choosiness and demands for investment. Observation: lots of cuckoldry (male invests in offspring that aren"t genetically his) Physical manifestation: gorillas? (all females choose to mate with 1 male)
