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Chapter 15
Vocabulary
Term | Definition |
---|---|
evolution | a heritable change in the characteristics within a population from one generation to the next; the development of new types of organism from preexisting types of organisms over time |
strata | layers of rocks |
natural selection | the process by which individuals that are better adapted to their environment survive and reproduce more successfully than less well adapted individuals do; a theory to explain the mechanism of evolution |
adaptation | the process of becoming adapted to an environment; an anatomical, physiological, or behavioral trait that improves an organism's ability to survive and reproduce |
fitness | in evolutionary theory, a measure of an individual's hereditary contribution to the next generation |
fossil | the trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock |
superposition | a principle that states that younger rocks lie above older rocks if the layers have not been disturbed |
relative age | the age of an object in relation to the ages of other objects |
absolute age | the numeric age of an object or event, often stated in years before the present, as established by an absolute-dating process, such as radiometric dating |
biogeography | the study of the geographical distribution of living organisms from or to the environment |
homologous structure | anatomical structures in one species that, compared to other anatomical structures in another species, originated from a single anatomical structure in a common ancestor of the two species. |
analogous structure | an anatomical structure in one species that is similar in function and appearance, but not in evolutionary origin, to another anatomical structure in another species |
vestigial structure | a structure in an organism that is reduced in size and function and that may have been complete and functional in the organism's ancestors |
phylogeny | the evolutionary history of a species or taxonomic group; the relationships by ancestry among species or taxonomic groups |
convergent evolution | the process by which unrelated species become more similar as they adapt to the same kind of environment |
divergent evolution | the process by which two or more related but reproductively isolated populations become more and more dissimilar |
adaptive radiation | an evolutionary pattern in which many species evolve from a single ancestral species |
artificial selection | the selective breeding of organisms for specific desirable characteristics |
coevolution | the evolution of two or more species that is due to mutual influence, often in a way that makes the relationship more mutually beneficial |