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How Humans Evolved, 6e
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AnthroTours
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16
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AnthroTours
Ebook
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AnthroTours
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AnthroTours
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AnthroTours
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AnthroTours
Ebook
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Diagnostic/Quiz+ Multiple-Choice Quizzes
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AnthroTours
Ebook
Study Plan
Chapter Learning Objectives
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Diagnostic/Quiz+ Multiple-Choice Quizzes
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AnthroTours
Ebook
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Chapter Learning Objectives
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Diagnostic/Quiz+ Multiple-Choice Quizzes
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AnthroTours
Ebook
Study Plan
Chapter Learning Objectives
Chapter Review
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Diagnostic/Quiz+ Multiple-Choice Quizzes
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AnthroTours
Ebook
Study Plan
Chapter Learning Objectives
Chapter Review
Chapter Outline
Diagnostic/Quiz+ Multiple-Choice Quizzes
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AnthroTours
Ebook
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Chapter Learning Objectives
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Diagnostic/Quiz+ Multiple-Choice Quizzes
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AnthroTours
Ebook
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Chapter Learning Objectives
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Diagnostic/Quiz+ Multiple-Choice Quizzes
Vocabulary Flashcards
AnthroTours
Ebook
Study Plan
Chapter Learning Objectives
Chapter Review
Chapter Outline
Diagnostic/Quiz+ Multiple-Choice Quizzes
Vocabulary Flashcards
AnthroTours
Ebook
Study Plan
Chapter Learning Objectives
Chapter Review
Chapter Outline
Diagnostic/Quiz+ Multiple-Choice Quizzes
Vocabulary Flashcards
AnthroTours
Ebook
Study Plan
Chapter Learning Objectives
Chapter Review
Chapter Outline
Diagnostic/Quiz+ Multiple-Choice Quizzes
Vocabulary Flashcards
AnthroTours
Ebook
Study Plan
Chapter Learning Objectives
Chapter Review
Chapter Outline
Diagnostic/Quiz+ Multiple-Choice Quizzes
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AnthroTours
Ebook
In This Chapter
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AnthroTours
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Chapter 6
Primate Mating Systems
Chapter Study Outline
Mating Systems Are Adaptive
Primate behavior is strategic in that it occurs in a specific functional context. Examples include mating, foraging, and parenting.
Evolution of Reproductive Strategies
Selection pressures influence the amount and pattern of parental investment.
Mammalian anatomy requires primate females to invest in their offspring.
Female Reproductive Strategies
Female primates are heavily invested in their offspring, which are slow to develop because of their large brain size.
Females need access to good nutrition for reproductive success.
Female fertility declines in old age.
High-ranking females produce more offspring than low-ranking females because of access to necessary resources.
A dominance hierarchy or a dominance matrix can be used to describe competitive encounters among members of a primate species.
Social bonds have an effect on reproductive success.
Reproductive trade-offs:
If a mother invests effort in one offspring, she has less effort to invest in others.
Mothers can change their behavior, distancing themselves from their offspring and allowing them to become independent.
Many primate mothers must wean their infants before they can conceive additional offspring.
Male Mating Strategies
Sexual selection
Increases male success in competition for mates
Can have a greater effect on behavior and morphology than other forms of natural selection
Can be much stronger on male primates than on female primates
Intrasexual selection
Favors traits that enhance fitness in male–male competition
Favors males who win competitions; they have higher reproductive success
Favors larger body size and larger teeth
Leads to the evolution of sexual dimorphism
Male Reproductive Strategies
Investing males
Are often pair-bonded
Sometimes engage in mate guarding
Enhance female fertility
Male–male competition
Males compete to establish residence in groups of females.
Conflict arises over group membership and access to females.
Competition is often mediated through dominance relationships.
Infanticide
Has been documented in about 40 primate species
Appears to be part of sexual selection, as males achieve reproductive benefits
Is associated with changes in male residence or status
Occurs so that the mother can become fertile again
Males do not kill their own infants.
Females have evolved responses to infanticidal threats.