The world around us is constantly changing. The ever-so noticeable climate change and the expansions of cities and industrial areas are a big influence on the environment. Individuals have to be able to adapt to these changes.
On the molecular level the individual activates defence mechanisms specifically designed to respond to certain situations. It is known that this is found in the coding region of the genome, but recent evidence shows that parasitic DNA, that is believed to be a remnant of viruses/bacteria, found in the genome has an effect on adaptation. The most important of these are transposable elements(TEs) that change their location in the genome. Research suggests that certain TEs have increased activity under stressful conditions and if this activity increases the fitness of the individual, this modified allele/trait will be passed on to the progeny.
As shown by Slotkin & Martienssen (in the article found here) with their experiment in coat colour in mice, dietary supplementation with methyl-group donors for DNA and histone methylation was shown to cause a shift in coat colour in the offspring of mice. This proves the inheritability of the actions of these TEs.
It is not known to what extent stress affects endogenous responses mediated through TEs, but we can see the benefits of research in this field.
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Primary Reference:
Slotkin, R.K. & Martienssen, R., 2007 “Transposable elements and the epigenetic regulation of the genome, Nature Reviews Genetics, [Online]Available at: http://www.nature.com/nrg/journal/v8/n4/box/nrg2072_BX4.html, viewed 10/09
