BIOL 122 Chapter Notes - Chapter 6: Santa Barbara City College, Species Complex, Indel
Document Summary
Pop= group of same species living in the same location. Species= group of orgs that naturally interbreed and produce fertile offspring. Species boundaries and spatial limits of a population are directly connected. Natural selection is primary non random mechanism of evolution within populations, but not only mechanism. Evolution= change in pop"s gene pool over time. Heritable phenotype of more reproductively successful indys is more prevalent in following generation. Pleiotropy= single genetic change, multiple phenotypic effects. Epistasis= hierarchal control of expression of one gene by another gene. Polygenetic traits= complex interactions among many genes, resulting in continuously varying phenotypic traits. Performance interacts with environment to determine selection. Strength of selection is measured in lifetime reproductive success (evolutionary fitness) Fitness is determined by which traits are selected by enviro. Nat selec is ecological process acting on phenotypic variation. Stabilizing selection= same mean, variance is contracted. Directional selection= shape of dist stays same but dist moves, mean changes but variance stays same.
