Changes

Epigenetic inheritance allows for more dramatic and rapid phenotypic change withinin populations across generations, and thus more rapid [[adaptation]] to environmental change, than random [[mutation]] alone.  In some species, certain traits are known to be on a sort of epigenetic "on/off switch" (e.g. the presence or absence of protective spines in ''Raphanus raphanistrum'', the wild radish), where they can be activated or deactivated between generations in response to environmental challenge<ref>http://www.annualreviews.org/doi/full/10.1146/annurev.genom.9.081307.164445</ref><ref>http://www.ncbi.nlm.nih.gov/pubmed/19606595</ref><ref>http://www.ncbi.nlm.nih.gov/pubmed/19606595</ref>.

Epigenetic inheritance allows for more dramatic and rapid phenotypic change withinin populations across generations, and thus more rapid [[adaptation]] to environmental change, than random [[mutation]] alone.  In some species, certain traits are known to be on a sort of epigenetic "on/off switch" (e.g. the presence or absence of protective spines in ''Raphanus raphanistrum'', the wild radish), where they can be activated or deactivated between generations in response to environmental challenge<ref>http://www.annualreviews.org/doi/full/10.1146/annurev.genom.9.081307.164445</ref><ref>http://www.ncbi.nlm.nih.gov/pubmed/19606595</ref><ref>http://www.ncbi.nlm.nih.gov/pubmed/19606595</ref>.

Epigenetic silencing also thought to provide a natural protection against [[retrovirus|retroviruses]] and inappropriate activation of [[transposons|transposable DNA elements]] (segments of DNA that move around in the genome)<ref>Simmen et al. (1999).  Nonmethylated transposable elements and methylated genes in a chordate genome. ''Science'' 283, 1164-1167.</ref>.  Although, the precise nature of this role is still somewhat disputed and remains an active area of research.

Epigenetic silencing is also thought to provide a natural protection against [[retrovirus|retroviruses]] and inappropriate activation of [[transposons|transposable DNA elements]] (segments of DNA that move around in the genome)<ref>Simmen et al. (1999).  Nonmethylated transposable elements and methylated genes in a chordate genome. ''Science'' 283, 1164-1167.</ref>.  Although, the precise nature of this role is still somewhat disputed and remains an active area of research.

However, the most important role of epigenetic gene regulation, by far, is in differential [[gene regulation]] during [[developmental biology|development]], where epigenetic reprogramming is a major regulator of [[cell differentiation]].

However, the most important role of epigenetic gene regulation, by far, is in differential [[gene regulation]] during [[developmental biology|development]], where epigenetic reprogramming is a major regulator of [[cell differentiation]].