Natural Selection PredatorPrey Interaction April 10 2003 Steven

Natural Selection & Predator-Prey Interaction April 10, 2003 Steven J. Ehrlich

Today Notes and Terms n Game n What to turn in: * Tables from pages 147 -152 n

Terms n Predation – When individuals eat other living individuals. n Adaptation – When newly -evolved traits increase the ability of an organism to survive.

Terms (continued) n Fitness (In Natural Selection) – A Genotype’s (or phenotype’s) reproductive contribution to subsequent generations relative to the contribution of other genotypes or phenotypes

Terms (continued) n n Coevolution – The process of reciprocal evolutionary changes, involving the response of two or more populations. Morphs – A phenotype of a species.

Natural Selection n Darwin’s Theory – Genotypes / Phenotypes – “Only the strong survive” – Predation, Adaptation, Co-evolution & Fitness

Natural Selection Game n Description of the game – Using 3 different utensils (predators), we will pick up 4 different types of beans (prey), to see which is the most fit predator, and the most fit prey.

Natural Selection Game (continued) n The rules – – Groups – Predators/prey – 2 x 2 meter – 2 minutes – Calculations – Generations

Natural Selection Game (continued) n Formulas used – Handout – Fitness Formula (Predator): W i = C i / ΣC N i / ΣN Or Fitness of knife = # of captures by the knife/ total # of captures # of knives / total number of predators

Natural Selection Game (continued) n Fitness Formula (prey): wj = e j / Σe n j / Σn Fitness of Pinto = # of pinto escapes / total # of escapes # of pinto beans / total # of beans