Unit 22-23: Evolution Flashcards
Divergent Evolution
share a common ancestor
Convergent Evolution
phenotypes are similar, do not share a common ancestor
Evidence of Evolution
Fossil records, anatomy, embryology, bio geography, molecular biology
Gene flow
movement of alleles among populations, by migration, increases variation
Kin Selection
the evolutionary behavior that favors the reproductive success of an organisms relatives (sisters/brothers) (altruism)
Genetic Drift
changes in allele frequencies due to chance
Bottleneck Effect
caused by a severe reduction in pop, reduces overall diversity
Founder Effect
ex. of genetic drift where rare alleles or combos occur in higher frequency in a pop isolated from the general population (Dwarfism in Amish communities)
Altruism
cooperative behavior within social groups
Directional Selection
one phenotype is favored over another, causes a shift in the overall appearance of the species
Stabilizing Selection
occurs when extreme phenotype are eliminated and the intermediate phenotype is favored
Disruptive Selection
occurs when extreme phenotype are favored and can leaed to more than one distinct form