ZOO 4070 Lecture Notes - Lecture 14: Operational Sex Ratio, Estrous Cycle, Parental Investment
23 Mar 2016
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Document Summary
Darwin: sexual selecion and the decent of man . Evoluion and maintenance of exaggerated traits that do not beneit survival prospects of individuals. Leads to non-random maing success in one of both sexes. 2 ways in which selecion can occur: intrasexual selecion. Male-male compeiion for access to mates: intersexual selecion. One sex selecively chooses mates: can move traits beyond natural selecion opimum. Males gain more with each addiional female they mate with. Females gain litle by maing with muliple males. Females have large limited eggs and males have unlimited small sperm. How did diferences in gamete size evolve: natural variaion in gamete size, selecion large gametes that increase reproducion, selecion small, mobile gametes that ind large ones, medium size fails as it doesn"t do as well as either. Trivers: females invest more in gamete producion and therefore parental care (typically) A- 20 ofspring this year, 0 ofspring subsequent years (20)
