| A | B |
|---|
| population | group of interbreeding individuals |
| gene pool | all genetic information in a population |
| directional selection | one phenotypic extreme is more likely to reproduce |
| stabilizing selection | phenotypic extremes are less likely to reproduce |
| disruptive selection | both extremes more likely to reproduce than median phenotypes |
| natural selection | selective force resulting from organism/environment interactions |
| humans on earth | example of a population |
| taller giraffes eat more, live longer | example of directional selection |
| small frogs can hide in holes, large frogs can jump away from predators | example of disruptive selection |
| small dinosaurs get eaten, large ones can't get enough food | example of stabilizing selection |
| sexual selection | choosing of a mate by the male or female of a species |
| a male elk fights off other males, and the females mate with the "winner" | example of sexual selection |
| gene flow | movement of alleles into or out of a population |
| genetic drift | change in allele frequencies in population as a result of random processes |
| a raccoon floats on a log to an island off Maine and mates with "native" racoons | example of gene flow |
| due to non-uniform mating, bark on pine trees thicckens over generations | example of genetic drift |
| mutation | changes in alleles - only source of new genetic material |
| a meiosis mistake causes badgers to have longer claws | example of mutation |
| bottleneck | reduction in population allele variation through extreme reduction in number of individuals |
