ANTH 350 Lecture 3: Forces of Evolution
Document Summary
Can look at evolution through artificial selection. Process where humans select for certain traits they find desirable in humans. Breeder makes the decision and chooses which animals will breed and which animals will not. Does not have to be based on traits that will help the animal survive and reproduce: directional selection. Natural selection that drives evolutionary change by selecting for greater or lesser frequency of a given trait in a population. Selection that maintains a certain phenotype by selecting against deviations from it. Sparrows who lived had shorter wings, smaller bodies. Natural selection selected out sparrows that deviated too far from the norm. Newborns who deviate from average are less likely to survive: gene flow. Migration is just movement, gene flow is the genetic material inside the genotype being passed on. Increasing gene flow and stopping gene flow both contribute to evolutionary change. Ex: mutiny on the bounty (pitcairn island) crew end up on pitcarin island.
