PSYCH 230 Chapter Notes - Chapter 1: Fitness Landscape, Mutation, Natural Selection
Document Summary
Dynamics of adaptation and diversification: a 10,000 generation experiment with bacterial. Studied evolutionary change in 12 populations of escherichia coli (asexual) propagated for. Morphology (cell size) and fitness (compared to that of ancestor) evolved rapidly for the first. 2000 generations after the population was introduced into the experimental environment. Proving that evolutionary change does not linearly progressively happen, unless need be. Although the populations were evolving in identical environments, the replicate populations diverged in morphology and fitness. Populations approached different fitness peaks of unequal height in the adaptive landscape. Observed periods of rapid evolution and stasis & altered functional relationships between traits. Results support wrightian interpretation: chance events (mutations/drift) play important roles in adaptive evolution as do the complex genetic interactions that underlie the structure of organisms. Mutations and genetics are both important in evolution. If environment doesn"t change for a given amount of time, then the phenotypic traits are to be genetic instead of mutational.
