Sexual Selection
A form of natural selection that results from differential mating success in one sex
Intrasexual Selection
Sexual selection where males compete with each other
Intersexual Selection
Sexual selection in which females choose their mates
Bachelor Males
Males who don't belong to social groups
Estrus
A period during the reproductive cycle of most mammals when the female is receptive to mating and can conceive
Sexual Selection Infanticide Hypothesis
A hypothesis postulating that infanticide has been favored by sexual selection because males who kill unweaned infants can enhance their own reproductive prospects if they (1) kill infants whose deaths hasten their mothers' resumption of cycling, (2) do n
Altruistic Behaviors
Behaviors that benefit others but at a personal cost
Kin Selection
Selection could favor altruistic alleles is animals interacted selectively with their genetic relatives
Hamilton's rule
rb>c; benefits outweigh costs
Coefficient of relatedness
measures the genetic relationship between interacting individuals of probability that two individuals will acquire the same allele through descent from a common ancestor
Phenotypic matching
recognizing kin by smell of likeness to themselves
Affilitave
(friendly) contact and to reinforce social relationships with other group members
Coalitions
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Alliances
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Chimeras
organisms that carry more than one genetically distinct population of cells derived from more than one zygote, occurs in marmosets
Chorion
membrane that surrounds the embryo in uterus, stem cells passed between them
Parent-offspring conflict
conflict that arises over how much the parents will invest in the offspring
Reciprocal altruism
altruism among individuals can evolve if altruistic behavior is balanced between partners over time
High quality: ripe fruit (1)
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High quality: ripe fruit (2)
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Medium quality: fruit and foliage
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Low quality: foliage and fruit
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Within group competition: disperse (1)
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Within group competition: disperse (2)
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Less intense competition
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Relaxed; flexible response
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