ANT 1 Lecture Notes - Lecture 6: Selective Breeding, J. B. S. Haldane, Sewall Wright
Document Summary
Lecture 6: the modern synthesis: revisiting the issue of variation challenges to darwin"s ideas: Blending" eliminates genetic variation: we have seen (with mendel"s help) that one allele for each locus is inherited from each parent. In mendel"s experiments: discontinuous variation (yellow or green peas, no intermediate cases (complete dominance) Apparent blending: quantitative genetics the study of continuous traits. Ex: hair, eye, and skin color; height, weight, blood pressure, etc . The modern synthesis (~1920-1950) reconciled mendel & darwin. Population genetic work of ra fisher, jbs haldane, and sewall wright. Polygenic traits continuous traits are affected by genes at many loci. Each locus has a small effect on the phenotype. The modern synthesis (synthetic theory of evolution: dawin"s theory of natural selection, mechanisms of inheritance (mendel, how variation is maintained, mechanisms for speciation. Look at the differences when more than one locus affects the beak depth. The more loci that contribute to the phenotype, the more continuous range there will be.
