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Costs of Learning. Learning: Alters Behavior, Functional Efficiency Takes Advantage of Predictability Within -Generation When Uncertainty Among Generations Fitness Benefits Well Understood Plasticity, Match Behavior to Environment Vertebrates & Invertebrates
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Costs of Learning Learning: Alters Behavior, Functional Efficiency Takes Advantage of Predictability Within-Generation When Uncertainty Among Generations Fitness Benefits Well Understood Plasticity, Match Behavior to Environment Vertebrates & Invertebrates Advances Survival & Reproduction
Social Learning (Cultural Transmission) Fitness Benefit: Predator Recognition Boreal chorus frog (Pseudacris maculata) Tadpoles: Naïve Woodfrog (Rana sylvatica) Tadpoles: Models Tiger salamander (Ambystoma tigrinum) Odor: Predator on tadpoles
Costs of Learning Nature: Learning Capacities Common Selectively Favored If Select for Increased Learning, Improves Rats, Bees & Several Dipterans If Learning Advantageous, Why Doesn’t Natural Selection Favor Increase? Selection for Intermediate Learning Capacities? Improvement Costly?
Costs of Learning Dichotomize Costs Constitutive (Genetic) Costs Capacity Costly, Even if Not Used Operating Costs Processes of Collecting, Storing & Recalling Information Costly
Constitutive Costs Develop & Maintain Sensory/Nervous Systems Neural Tissue Metabolically Expensive Pleiotropic Costs: Energy/Resource Allocation to Sensory/Nervous Functions Might Reduce Life-History Traits ~Independent of Use
Operating Costs Paid When Animal Learns Energy, Metabolic Resources Time, “Attention” Pleiotropic Costs to Other Traits
Operating Costs Well Studied, e.g.: Mice: Reduced Immunity Barnard et al. 2006. Behav. Process. 72:74. Fruit Flies: Loss Larval Competitive Ability Mery & Kawecki. 2003. Proc. R. Soc. B270:2465. Mery & Kawecki. 2005. Science 308:1148. Fruit Flies: Reduced Fecundity Mery & Kawecki. 2004. Anim. Behav. 68:589.
Mery & Kawecki. 2004. Anim. Behav. 68:589. DrosophilaLines Artificially Selected for High Learning Low Learning (No Learning Selection) Quinine Aversion During Oviposition (1 Sex!) Selected Lines: Faster Learning & Longer Memory
Mery & Kawecki. 2004. Anim. Behav. 68:589. Selected vs Unselected: Constitutive Costs In Selected Lines No Conditioning vs Repeated Conditioning: Operating Costs in High-Learning Line
Mery & Kawecki. 2004. Anim. Behav. 68:589. Correct Oviposition: High-Learning Line Advantaged, Given Chance to Learn Does Advantage Imply Operating Cost?
Mery & Kawecki. 2004. Anim. Behav. 68:589. Egg Laying: Conditioning Affects High-Learning Only Reduced Fecundity in Later Cycles No Cost in High- Learning Without Conditioning
Burger et al. 2008. Evolution 62:1294. Drosophila Lines Artificially Selected for High Learning Low Learning (No Learning Selection) Separate Lines Selected for Longevity
Burger et al. 2008. Evolution 62:1294. Drosophila Lines Artificially Selected for High Learning Low Learning (No Learning Selection) Separate Lines Selected for Longevity: Focus on Constitutive Costs of Learning
Burger et al. 2008. Evolution 62:1294. Selection for Learning Effective Costs?
Burger et al. 2008. Evolution 62:1294. Cohort Survival: High-Learningvs Control Learning: Both Sexes Significantly Shorter Lifespan
Burger et al. 2008. Evolution 62:1294. Select for Longevity: Works; Median Lifespan Extended By 18 Days Learning Impaired?
Burger et al. 2008. Evolution 62:1294. Pleitropic Cost: Longevity Impairs Learning, 1 Hour Memory Task (Avoidance of Mechanical Shock Via Odor Association)
