BIOL 1F90 Lecture 10: LECTURE 10 winter
6 Feb 2017
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Document Summary
Directed at certain traits of sexually reproducing species that make it more likely for individuals to find or choose a mate and/or engage in successful mating in many species, affects male characteristics more intensely than it does female. Between members of the same sex: horns in male sheep, antlers in male moose, male fiddler crab enlarged claws, males directly compete for mating opportunities or territories intersexual selection female choice. Often results in showy characteristics for males cryptic female choice: genital tract or egg selects against genetically related sperm inhibits inbreeding. Intersexual selection also explains traits that decrease survival but increase reproductive success: male guppy (poecilia reticulata) is brightly coloured compared to the female females prefer brightly coloured males. Genetic drift changes allelic frequency due to random chance random events unrelated to fitness favours either loss or fixation of an allele frequency reaches 0% or 100% faster in smaller populations.
