BIO120H1 Lecture Notes - Lecture 18: Genetic Drift, Genetic Marker, Gene Flow
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BIO120H1 Full Course Notes
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Lecture 18: population structure, gene flow and genetic drift. Multiple populations across the landscape; the genetic variation that gives rise to speciation- population differentiation. ie: patterns of variability in the rat snake. Fisher and wright had very different viewpoints: how important genetic drift is as an evolutionary process: wright saw an important role for population structure and genetic drift in evolution. If you looked at real populations (not hypothetical), would see a lot of population structure across the landscape- some big, some small- small populations could play an important role in evolutionary change. Structure across the landscape in causing differentiation- suggested that genetic drift was a player, along with natural selection: fisher disagreed and argued that most evolution occurred in large populations by natural selection. Most important evolutionary change that gives rise to adaptation occurred in large populations through selection. Structure and genetic differentiation: two habitats are close together; trees occur on both sides.
