PSYC 3100 Lecture Notes - Lecture 26: Cuckold, Internal Fertilization, Limiting Factor
11 Apr 2018
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Document Summary
Male claims of proprietary entitlements of females are responses to rivalry over limited resources. The combination of this paternal investment, an asymmetrical risk of cuckoldry, internal fertilization and high paternal investment produces a powerful selective force favouring the evolution of propriety. Costs of female extrapair mating: gametes in excess, risk of disease transmission or damage during sex, possible withdrawal of paternal investment, possibly higher competition among o spring of mixed paternal relatedness, violence. Bene ts of female extrapair mating: superior genes, possible material bene t from adulterers, distributed paternal possibility may cause increased total investment. Sperm competition: competition for mates does not end at mating - only one male"s sperm will fertilize each egg. Not about who got the most matings, it"s about who got the most fertilizations: sperm competition: any sperm-related acts that increase the likelihood that one"s sperm will fertilize the eggs. Chimps: a female will mate with almost every male in the group = high sperm competition.
