evolution (redirected from Darwin's theory of evolution)

evolution /evo·lu·tion/ (ev?ah-loo´shun) a developmental process in which an organ or organism becomes more and more complex by differentiation of its parts; a continuous and progressive change according to certain laws and by means of resident forces.

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convergent evolution  the appearance of similar forms and/or functions in two or more lines not sufficiently related phylogenetically to account for the similarity.

organic evolution  the origin and development of species; the theory that existing organisms are the result of descent with modification from those of past times.

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ev·o·lu·tion (v-lshn, v-)

n.

1. A continuing process of change from one state or condition to another or from one form to another.

2. The theory that groups of organisms change with passage of time, mainly as a result of natural selection, so that descendants differ morphologically and physiologically from their ancestors.

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evolution

the process of development in which an organ or organism becomes more and more complex by the differentiation of its parts; a continuous and progressive change according to certain laws and by means of resident forces.

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convergent evolution

the development, in animals that are only distantly related, of similar structures or functions in adaptation to similar environment.

divergent evolution

the development of different characteristics in animals that were closely related in response to being placed in different environments.