Study Guide Lectures 12-16

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University of Toronto St. George
Ingrid L.Stefanovic

Lecture 12: Proximate causes J Z}M,}}ZZZZ]L2ZZL; Ultimate causes J ZMJZ}ZZZZ]L2ZZL;Z ZZK Behaviour : Narrow definition: how an animal responds or acts to a stimulus where the stimulus maybe another animal or some aspects of environment }]L]]}L9^ ]Z]}LZ_K}2L]ZKZ Theodosius Dobzhansky J nothing in bio makes sense except in the light of evolution J we can naming, describing and categorizing thing without evo, yet cannot understand things without it. Three requirements for evolution by NS (important): a) Variation in traits J feactures in organisms are variable among individuals b) Variation in fitness due to that trait J aspects of the variations affect fitness c) Genetic bases for the trait J the genetic base of the favorable traits accosciated with reproduction and survival will evolve. Phoentype is related to genes and environment Experiments: roversitter polymorphism Present of food J move in different distances according to the genotype, lack of food J move in same amount distance. Rovers move much greater distance than sitters when food is patchy, more likely to find new food Environmental effects on trait values can be described as plasticity The infulence of genes and environment can be visualized with plots of the reaction norm Reaction norm J the response of any trait to different environments. Phenotype has a function of environment Genetic J environment interaction J we can not distinct those two aspects, have to thought together. Gene and bahaviour: Z(behaviour)=G(gene)+E(environment) Behaviours ar shaped by evolution Genes and environment infulence the behaviour J cannot be distinct! Environmental effects on trait valure can be described as plasticity Natural selection shape the reaction norm Lecture 13: 3 main components of the optimization models are currency, constraints and decision variable Foraging study played a central role in behavioural ecology because it is ultimately related to fitness. Process of science J observation Jthroey-hypothesis Jtheory Forgaing in groups J lower the risk J more protective from predation J more successful for hunting Camouflage J confused the predators in order to escape Consider about the cost-benefit balance J move aroung cost energy but can get bigger chance to get new food J how long should a animal stay in a certain place how often should them travel The optimization approach: Economic thinking J trade-offs cost-benefit analysis Central idea: selection expected to produce phenotypes that represent the best achievable balance of the cost and benefits of a decision J any trait. Optimality J best balance between cost and benefit However, organisms achieve the best foraging strategy is not possible in nature J a descision that is optimal in a condition may not be the best one in another condition Either of the cost and benefit changes J the optimal phenotype will change Appliactions of optimization theory:
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