Evolution by natural selection
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Created by:
gabbywabby15 on February 12, 2012
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25 terms
Terms | Definitions |
|---|---|
 typological thinking | Plato. Species unchanging. Variations within species are unimportant or misleading |
| aristotle | who thought that species are fixed. some species are higher-sense of greater complexity "better" |
| Lamarck | who thought that simple organisms originate at the base by spontaneous generation and evolved by moving up chain over time; change over time via inheritance of characteristics |
| population | individuals of the same species that are living in the same area at same time |
| population thinking | variation among species=key to understanding nature of species |
| natural selection | overturned the idea that species are static and unchanging. replaced typological thinking w/ population thinking. proposed a mechanism to account for change |
| descent through modification | species change through time. species related by common ancestry |
| extant species | species living today |
| radioactive decay | dates fossils |
| law of succession | extinct species in fossil record were succeeded by similar species |
| transitional feature | intermediate b/t those of older and younger species |
| phylogeny | family tree of populations or species through homology |
| developmental homology | type of homology seen in embryo development like gills and tails |
| genetic homology | type of homology DNA sequence similarity |
| structural homology | type of homology like how limbs look |
| evolution | defined as a change in allele frequencies in a pop over time. heritable info leads to differential reproductive success |
| biological fitness | ability of an indiv to produce surviving offspring relative to other indiv in pop. increased by adaptations |
| adaptions | increase fitness; restrained by history because all traits have evolved from previously existing traits |
| Darwin's postulates | variation exists. variation is heritable. variation in reproductive success. selection occurs |
| allele frequency | changes in pops not individuals. natural selection acts on individuals. |
| natural selection | during this process, individuals DON'T change, but populations DO. sorts existing variants; doesn't change them |
| acclimation | changes in individual's phenotype in response to changes in environmental conditions |
| evolution | not goal directed; mutations occur randomly |
| genetic correlation | occur due to pleiotropy in which a single allele affects multiple traits |
| fitness-trade off | compromise b/t traits in terms of how those traits perform in the environment. |
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