BIO 10-Drift& Gene flow08WEB

BIO 10-Drift& Gene flow08WEB -...

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04/26/10   1 8-Drift, Gene flow, mutation October 8 Lecture 10
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04/26/10   2 Outline Genetic drift continued Gene flow Case study
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04/26/10   3 Lab 3 NO labs next week Cycle 1—lab 3 week of Oct 20 Pre-lab quiz weekend before Cycle 2—lab 3 week of Oct 27
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04/26/10   4 Tutorial 4 Friday Drift, Gene Flow (and how they affect  variation compared to natural selection) SEE Tutorial folder
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04/26/10   5 Genetic drift can affect  evolution Genetic drift =random, unpredictable  changes in allele frequencies unrelated  to fitness
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04/26/10   6 genetic drift Thought questions: 1. In small populations, explain why we say that drift is the evolutionary equivalent of a sampling error . 2. Why does drift have less impact on  large populations?
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04/26/10   7 Clicker : Why does drift have less  impact on large populations? A. Random changes do not happen in large  populations. B. Random changes in one direction are  balanced by random changes in the other  direction. C. Selection is more important in large  populations than in small. D. Gene flow counteracts any random changes  in large populations.
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04/26/10   8 Genetic drift does not usually affect  allele frequencies in large populations,  because  random changes in one direction are  balanced by other random changes  in the other direction.
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  9 Not all evolution is adaptive In addition to tradeoffs and constraints,  chance  plays a big roll e.g., Storm blows insects to a distant island.  Wind does not necessarily transport  specimens best suited to new environment! Alleles fixed by genetic drift are not necessarily 
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This note was uploaded on 04/25/2010 for the course BIO BIO152 taught by Professor Cordon during the Fall '09 term at University of Toronto- Toronto.

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BIO 10-Drift& Gene flow08WEB -...

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