Inherited Epigenetics Produced Record Fast Evolution

http://www.sciencedaily.com/releases/2012/02/120229091844.htm

ScienceDaily (Feb. 29, 2012) — The domestication of chickens has given rise to rapid and extensive changes in genome function. A research team at Linköping University in Sweden has established that the changes are heritable, although they do not affect the DNA structure.

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Degrees of a kind of epigenetic modification, DNA methylation, were measured in several thousand genes. This is a chemical alteration of the DNA molecule that can affect gene expression, but unlike a mutation it does not appear in the DNA structure. The results show clear differences in hundreds of genes.

Researchers also examined whether the epigenetic differences were hereditary. The answer was yes; the chickens inherited both methylation and gene activity from their parentages. After eight generations of cross breeding the two types of chickens, the differences were still evident.

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Since methylation is a much faster process than random mutations, and may occur as a result of stress and other experiences, this may explain how variation within a species can increase so dramatically in just a short time.

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