An Evolutionary View of Behavior

1
An Evolutionary View of Behavior

• Starr/Taggarts
• Biology
• The Unity and Diversity of Life, 9e
• Chapter 47

2
Key Concepts

• Behavior refers to coordinated responses that an
  animal makes to stimuli
• Forms of behavior have a genetic basis
• Certain behaviors are instinctive and are
  triggered by sign stimuli
• The nervous system can process and retain
  information used to vary or change behavioral
  responses

3
Key Concepts

• Behavior has evolved by way of natural selection
• Evolved modes of communication underlie social
  behavior
• Having a social group has costs and benefits
• Altruistic behavior allows individuals to help
  others while sacrificing personal reproductive
  success

4
Decorating BehaviorStarling Nest
Fumigation of nests preventing mite infestation

• A - No sprigs in nest from wild carrots
• B - Sprigs in nest of wild carrots
• Wild carrot sprigs reduce mite infestations

5
Genes and Behavior

• Nervous system
• Sensory
• Hormones
• Melatonin secretion
• Seasonal
• Estrogen

• Instinctive
• Behavior not learned
• Cues in environment
• Sign stimuli
• Fixed action pattern

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Learned Behavior

• Imprinting
• Classical conditioning
• Operant conditioning
• Habituation
• Spatial or latent learning
• Insight learning

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Fig. 47.7, p. 836
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The Adaptive Value of Behavior

• Reproductive success
• Behaviors
• Adaptive
• Social
• Selfish
• Altruistic

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Communication Signals

• Signals
• Signal receivers
• Pheromones
• Composite signal
• Illegitimate signals
• Illegitimate receivers

• Displays
• Pattern behavior
• Threat
• Courtship
• Tactile

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Dances of Honeybees

• Tactile displays

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Reproductive Success

• Sexual selection
• Quality of mate
• Parenting
• Benefits of social groups
• Cost-benefit approach
• Cooperative predator avoidance
• Selfish herd
• Dominance hierarchies

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Fig. 47.21, p. 847
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Cost of Living in Social Groups

• Competition for food
• Competition for mate
• Spread of contagious disease and parasites
• Risk of being killed or exploited

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Evolution of Altruism

• Provide youth with prey
• Defend feeding territories
• Drive off intruders
• Theory of Indirect Selection
• William Hamilton
• Self - sacrifice genes
• Honeybees
• Termites

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An Evolutionary View of Human Social behavior

• Adaptations have costs and benefits
• Adoption
• Redirection of behavior
• Adoption of related children is greater than that
  of non-related ones
• Perpetuation of genes

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In Conclusion

• Animal behavior originates with genes that
  specify products required for the development and
  operation of different systems
• A behavior performed without having been learned
  by actual experience is instinctive
• Experiences can lead to variations or changes in
  responses

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In Conclusion

• Behavior with a genetic basis is subject to
  evolution and natural selection
• Members of the same species can create obstacles
  to one anothers reproductive success
• Social groups require cooperative interdependency
  among individuals of a species

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In Conclusion

• Chemical, visual, acoustical and tactile signals
  are components of communication displays
• Costs and benefits of social life are reflected
  in the individuals reproductive success
• Social groups have costs as well as benefits

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In Conclusion

• Altruistic behavior limits chances of
  reproduction by helping others of their social
  groups
• Dominance in a social group forces subordinates
  to relinquish resources
• Genes associated with caring for relatives can be
  favored in some cases
• developed by M. Roig