| A | B |
|---|
| speciation | formation of a new species |
| species | group of organisms that is different than any other group |
| geographic isolation | separation of a population due to geographic barriers or migration |
| adaptive radiation | many species evolving from a common ancestor due to diverse environments |
| reproductive isolation | when a reproductive barrier (time, structure) keeps similar species from interbreeding |
| punctuated equilibrium | theory of evolution where species stay the same for long periods of time followed by a short period of great change |
| vestigial structures | structures an organisms has that were used by ancient ancestors |
| homologous structures | similar structures found in species that share a common ancestor |
| microevolution | evolution on the smallest scale; changes from generation to generation in a population |
| adaptation | inherited characteristic that improves an organism's ability to survive and reproduce |
| natural selection | Darwin's explanation of how evolution occurs; individuals with adaptations leave more offspring |
| Charles Lyell | Geologist who proposed the earth was much older than previously thought |
| Jean Baptist Lamarck | Proposed acquired traits, characteristics changed during an organisms lifetime |
| Thomas Malthus | Economist who influenced Darwin by writing on how populations of humans grow faster than food supply and not all survive |
| fitness | being well suited to an environment |
| gene pool | all of the alleles of all of the individuals that make up a population |
| genetic drift | change in the gene pool of a population due to chance |
| macroevolution | major biological changes that can lead to new species forming |
| population | the smallest level where evolution can occur |
| allele | variations of a trait |
