LIFESCI 15 Lecture Notes - Lecture 14: Cuckold, Asteroid Family, Mating System
Document Summary
Thm #1: because female reproductive investment is initially higher, they are vulnerable early on. We expect the evolution of choosiness and demands for investment. Lower reproductive investment: more competition, need for paternity certainty: competition for access, mate guarding/extended mating, sperm competition/anti-sperm. Physical manifestation: gorillas? (all females choose to mate with 1 male, chimps? (everyone has sex with dozens of partners)-- testicles 16x larger than gorillas, humans: 4x bigger than gorillas and as big as chimps. A: males are more vulnerable when it comes to investing in the offspring. Might be investing in offsprings that are not his. Thm #2: initial low reproductive investment and paternity uncertainty lead to male-male competition for access to females, indiscriminate male mating, mate guarding, and sperm wars. Polygyny: [high variance in males rs]/[low variance in females rs: one male bonds with multiple females. Polyandry: [low variance in males rs]/[high variance in females rs: one female bonds with multiple males.
