Evolution: Biology

Overview: Evolutionary mechanisms

Mutation

Mutations are spontaneously occurring changes in the genome. They form the “raw material” for evolutive changes. Although they certainly are a source of diversity within species and basic types they do not give any evidence for the development of new structures.

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Natural Selection

Selection means the picking-out of the best adapted individuals out of a surplus of offspring. It expresses itself in varying succes of reproduction. Selection adds to the variation of already existing organs and structures, but cannot contribute to the development of new organs. Adaptation and  new development have nothing to do with each other.

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Breeding

Naturally occurring processes can be accelerated by breeders´ activities. This gives the possibility to test the efficiency of evolutionary factors. Studies of breeding show, that a considerable capacity of variation can be utilized while at the same time the possibilities of modification are limited.

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Speciation

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