Chapter 7 Models for Human Evolution

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Chapter 7 Models for Human Evolution

• Behavior and Human Origin
• Language Capabilities
• Primate Cultural Behavior
• Aggressive Interactions Between Groups
• Affiliation, Altruism and Cooperation
• The Primate Continuum

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Behavior and Human Origin

• Primate behaviors developed as a function of
  natural selection.
• Behaviors are similar in many primate species and
  may be adaptive in complex social settings.

3
Language Capabilities

• Language distinguishes humans from the rest of
  the animal kingdom.
• There is abundant evidence that humans are not
  the only species capable of symbolic thought and
  complex communication.

4
Primate Cultural Behavior

• Cultural behavior is learned.
• Nonhuman primates learn behaviors through
  observation, their mothers and others.
• Chimpanzees are the only nonhuman primate that
  consistently and habitually makes and uses tools.
  

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Cultural Behaviors in Nonhuman Primates - 8
Criteria

1. Innovation - Pattern is invented or modified.
2. Dissemination - Pattern is acquired.
3. Standardization - Pattern is consistent and
   stylized.
4. Durability - Pattern is performed without
   presence of demonstrator.

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Cultural Behaviors in Nonhuman Primates - 8
Criteria

1. Diffusion - Pattern spreads from one group to
   another.
2. Tradition - Pattern persists from one generation
   to the next.
3. Nonsubsistence - Pattern transcends subsistence.
4. Naturalness - Pattern is shown in absence of
   direct human influence.

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Aggression Between Groups

• Used to protect resource through defense of
  territories.
• Territoriality is associated with species whose
  ranges are small enough to permit patrolling and
  protection.
• Lethal unprovoked aggression between groups of
  the same species is known to occur only in humans
  and chimpanzees.

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Studies in Aggression

• Jane Goodall and her colleagues witnessed
  unprovoked and brutal attacks of chimpanzees by
  other chimpanzees.
• Territoriality and acquisition of females are the
  motives suggested for chimpanzee male aggression.

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Altruism

• Altruism is common in many primate species.
• Chimpanzees routinely come to the aid of family
  and friends.
• Chimpanzee orphans are routinely adopted.

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Cooperation

• Forming alliances, coalitions and grooming
  partnerships are all forms of cooperative
  behaviors.
• Chimpanzees hunt cooperatively.

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The Primate Continuum

• Human brains are larger than primate brains, but
  the neurological processes are functionally the
  same.
• The fact that humans are part of an evolutionary
  continuum is the basis for animal research, yet
  we cage nonhuman primates with little regard for
  the needs they share with us.