ANTH 215 Chapter Notes - Chapter 2: Genetic Drift, Gene Flow, Gamete
9 Oct 2018
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Causes of genetic variation: first exam next week, polygenetic inheritance cont. Polygenic traits or continuous traits are governed by alleles at two or more loci, and each has some influence on the phenotypes. Hair eye and skin color are examples of polygenic traits. Many polygenic traits are influenced by environmental factors. Ex: stature influenced by nutrition, genes, physical environment, diet, diseases, etc: factors that produce and redistribute variation. Genetic drift and founder effects (genetic bottlenecks) For a mutation to have evolutionary significance it must occur in a gamete. Otherwise wo(cid:374)"t (cid:271)e passed o(cid:374) to (cid:374)e(cid:454)t ge(cid:374)eratio(cid:374) Mutation rates for any given trait are usually low. New variation is only created through mutation: gene flow. If individuals move temporarily and mate in the new population leaving a genetic contribution (cid:271)ut the(cid:455) do(cid:374)"t (cid:374)e(cid:272)essaril(cid:455) alwa(cid:455)s sta(cid:455) there. Today gene flow much more possible due to mass transportation. Today people much more likely to move around and further.
