BIO 3122 Study Guide - Midterm Guide: Genetic Drift, Introduced Species, Tetrapod
23 Jan 2018
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Ground finches on daphne major differ in the thickness of their bills, the variation causes some indivs to be more efficient at processing hard seeds. Found large differences in selection on beak size depending on the season - unexpected. Saw evol changes in a natural popn that were as fast as those resulting from artificial selection. Breeders nonrandomly choose individuals with economically favorable traits to use as breeding stock, they impose strong artificial selection on those traits. During a severe drought on daphne major, subtle differences in beak thickness among medium ground finches affected who lived and died. Bc beak depth is highly heritable, natural selection could lead to rapid evol of beak size. Natural selection is direction if it favors increases, or decreases, in the size or dimensions of the trait. It is stabilizing or balancing if it favors the current value for the trait.
