| A | B |
|---|
| population genetics | study of evolution of populations from a genetic point of view |
| bell curve | graph of trait frequencies showing most individuals have medium phenotypes |
| gene pool | total genetic information available in a population |
| allele frequency | figure by dividing the number of an allele by the total number of all alleles in the population |
| phenotype frequency | number of individuals with a phenotype divided by the total number of individuals |
| Hardy-Weinberg genetic equilibrium | is achieved in a hypothetical population that is not evolving |
| immigration | movement of individuals into a population |
| emigration | movement of individuals out of a population |
| gene flow | the process of genes moving from one population to another |
| genetic drift | population allele frequencies change due to random events |
| stabilizing selection | individuals with average phenotypes have the highest fitness |
| directional selection | individuals with an extreme phenotype have the highest fitness |
| disruptive selection | individuals with either extreme have the highest fitness |
| sexual selection | individuals chosen as a mate because of their "sexy" phenotype |
| speciation | populations becoming different enough they are separate species |
| morphology | the appearance and structure of an individual |
| biological species | can only mate and produce offspring with their own species |
| geographic isolation | separation of a populations by Earth's structures |
| reproductive isolation | barriers to successful breeding between two different species |
| prezygotic isolation | reproductive isolation that happens before breeding |
| postzygotic isolation | reproductive isolation that occurs after fertilization |
| gradualism | a slow but constant change of a populations into separate species |
| punctuated equilibrium | rapid change of populations into separate species due to rapid environmental changes |
