Adapting Heritable Instinct

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Adapting- Heritable Instinct

• WFSC 422 Ethology
• Presentation 2.3

Dr. Jane M. Packard, WFSC TAMU j-packard_at_tamu.edu
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Concept Map- Adapting
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What is instinct?

• A behavior that is highly heritable
• occurs fully formed the first time
• occurs the same in all individuals
• same genotype
• raised in different environments
• more a result of genetic information than
  environmental information
• a behavioral trait subject to natural selection

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Example Archer fish spit
VIDEO
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Fixed Instinct no learned change
(evolutionary adaptation)
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What is natural selection?

• V Variation (PC)
• If there is variation in a trait (some fish spit)
• H Heritability (PD)
• If the variation is highly heritable (spit
  genotype)
• D - Differential Fitness (UF)
• If one genotype is more fit (spitters feed
  better)
• P - Proportion of genotypes changes (UE)
• Then the genotype would increase in a population
  (after many generations, all archer fish spit)

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Example- gull displays
VIDEO
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Natural selection long call

• V Variation (PC)
• If some gulls long-call and others do not
• H Heritability (PD)
• If the long-call is a highly heritable genotype
• D - Differential Fitness (UF)
• If gulls that call are more likely to attract
  mates, repel intruders, and feed their own chicks
• P - Proportion of genotypes changes (UE)
• Then over evolutionary history, all individuals
  within the species would long-call

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Critical thinking myth or science?

• Assumptions- do all these fit?
• there was variation in the trait (V)
• the variation was not learned (H)
• only this one trait influenced differential
  reproduction (D)
• no other trait had an opposite advantage (P)
• Can we assume the current environment is the same
  as during the past history of this species?

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Artificial vs. Natural Selection

• Similarities
• Variation is heritable
• Change in proportion of genotypes is related to
  differential fitness (survival reproduction)
• Both are constrained by genetics (cant breed for
  purple dogs)

• Differences
• Humans determine which genotypes survive
  reproduce
• Artificial selection is more consistent in line
  breeding
• Artificial selection happens over fewer
  generations

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Summary

• Evolutionary adaptation by natural selection
• change in genotypes resulting from natural
  selection (VHDP)
• solves problems encountered by the species over
  very long time-scales
• At the other end of the continuum from Learned
  adaptation
• Explains the logic behind Tinbergens 4 questions

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Action Items

• Search ISIwebofknowledge for natural selection
• Answer Q2.5, 2.6
• Post answers sources to Discussion Topic Unit 2
  on WebCT