Mechanisms of Evolution

Mechanisms of Evolution - natural selection tends to remove...

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Mechanisms of Evolution Evolution does not occur in individuals but in populations. A  population  is an  interbreeding group of  individuals of one species in a given geographic area. A population evolves because the population  contains the collection of genes called the gene pool. As changes in the gene pool occur, a  population evolves.  Mutation Mutation,  a driving force of evolution, is a random change in a population's gene pool. It is a change  in the nature of the DNA in one or more chromosomes. Mutations give rise to new alleles; therefore,  they are the source of variation in a population.  Mutations may be harmful, but they may also be beneficial. For example, a mutation may permit  organisms in a population to produce enzymes that will allow them to use certain food materials.  Over time, these types of individuals survive, while those not having the mutations perish. Therefore, 
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Unformatted text preview: natural selection tends to remove the less-fit individuals, allowing more-fit individuals to survive and form a population of fit individuals. Gene flow Another mechanism of evolution may occur during the migration of individuals from one group to another. When the migrating individuals interbreed with the new population, they contribute their genes to the gene pool of the local population. This establishes gene flow in the population. Gene flow occurs, for example, when wind carries seeds far beyond the bounds of the parent plant population. As another example, animals may be driven off from a herd. This forces them to migrate to a new population, thereby bringing new genes to a gene pool. Gene flow tends to increase the similarity between remaining populations of the same species because it makes gene pools more similar to one another....
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This note was uploaded on 11/11/2011 for the course BIO 101 taught by Professor Pesthy during the Fall '07 term at Texas State.

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