BIO120H1 Lecture Notes - Lecture 7: Genetic Drift, Gene Flow, Adaptive Radiation

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8 Dec 2016
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BIO120H1 Full Course Notes
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BIO120H1 Full Course Notes
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Boundaries between races/ morphs of species (adaptive radiation) e. g. different colours of rat snakes, e. g. micro climates between north and south facing slope. Fischer wright debate: wright saw an important role for pop structure and genetic drift, fischer disagreed, most evolution occurred in large populations by natural selections. Escape of transgenes into wild relatives by gene flow interfertile close relatives: e. g. rice, oats, canola etc: hybridization btw crops and related weeds, controversy abt gmo contamnation due to gene flow. Gene flow between crop and weed sunflowers: arias and rieseberg 1994, sunflowers pollinated by animals, most gene flow occurs over short distance, due to limiations of pollinators, use frequency markers to mark safe distances between crops. Escape of crop transgenes into wild relatives by gene flow. Risk assessment for isolation distances: proximity of wild relatives, pollination system- wind vs. animal, mating system- slefer vs. outcrosser, high risk: wind pollinated outcrosser with relative nearby, low risk: selfer with no relatives nearby.