BIOL 304 Lecture Notes - Lecture 26: Natural Selection, Stabilizing Selection, Genetic Variation
Document Summary
The rate of response to selection is equal to quantity of genetic variance. As variance increases, forces of selection increases proportionally (additive genetic variance) Amount of degradation correlates with force of selection. Genetic variance is only a small fraction of total variance. E. g. independent evolution of less armored freshwater stickleback fish. If a character is linked with fitness, selection on fitness will also indirectly affects this characters. The expected change in character z between generations. Will selection apply differently even when individuals are close (genetic flow in between) Result: each meadow and forest grass type has higher fitness in their local environment. E. g. locally involved mice color adaptation to environment. E. g. transplant between pasture and mine soil grass. Tolerance may evolved abruptly through gain of function mutation. Not all species evolve tolerance, especially in short term (ancestral constraint- conferring alleles) Taking pasture grass to mine field is facing much stronger selection.
