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

Ferrari & Chivers (2008) Animal Behaviour 75:1921.

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 Behav. Process. 72:74. Fruit Flies: Loss Larval Competitive Ability Mery & Kawecki Proc. R. Soc. B270:2465. Mery & Kawecki Science 308:1148. Fruit Flies: Reduced Fecundity Mery & Kawecki Anim. Behav. 68:589.

Drosophila Lines Artificially Selected for High Learning Low Learning (No Learning Selection) Quinine Aversion During Oviposition (1 Sex!) Selected Lines: Faster Learning & Longer Memory

Mery & Kawecki 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 Anim. Behav. 68:589. Conditioning Cycles No Conditioning High-Learning Line Constitutive Cost Constitutive + Operating Costs: Lower Operating Costs Low-Learning Line Lower Constitutive Costs Lower Constitutive Costs

Mery & Kawecki Anim. Behav. 68:589. Correct Oviposition: High-Learning Line Advantaged, Given Chance to Learn Does Advantage Imply Operating Cost?

Mery & Kawecki 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 Evolution 62:1294. Drosophila Lines Artificially Selected for High Learning Low Learning (No Learning Selection) Separate Lines Selected for Longevity

Burger et al 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 Evolution 62:1294. Selection for Learning Effective Costs?

Burger et al Evolution 62:1294. Cohort Survival: High-Learning vs Control Learning: Both Sexes Significantly Shorter Lifespan

Burger et al Evolution 62:1294. Select for Longevity: Works; Median Lifespan Extended By 18 Days Learning Impaired?

Burger et al Evolution 62:1294. Pleitropic Cost: Longevity Impairs Learning, 1 Hour Memory Task (Avoidance of Mechanical Shock Via Odor Association)