August 13, 2010
One of the big worries about climate change is that organisms will be unable to migrate or adapt quickly enough to deal with all the coming changes to their environments, which could lead to a lot of extinctions. But a new study led by the Royal Botanic Gardens, Kew, which appears in Molecular Biology and Evolution, shows that some plants may be able to adapt more quickly than expected due to epigenetics.
In traditional genetics, adaptation occurs through the development of random mutations in DNA and the survival, through natural selection, of those better fit for an organism’s environment. It is a slow process. But the genetics of organisms are actually far messier, and the DNA sequence of a gene is only one part of the picture. For instance, with DNA methylation, a methyl group attaches to DNA and results in less expression of that gene. Epigenetic effects like this can be directly influenced by an organism’s environment, and they can be quickly passed on to subsequent generations.
The new study focused on three recently formed species of European marsh orchids of the Dactylorhiza genus. The three species are very similar genetically, but have different appearances (though they’re all purple) and live in different environments. The researchers determined that the three orchid species diverged so quickly not because of changes in DNA sequence, but because of epigenetic variation.
“Our results show the importance of the environment in altering inherited traits in these orchids and also contributing to biodiversity,” said leader researcher Ovidiu Paun. “The epigenetic level of natural variation can be adaptive and has the potential to be rapidly released, in a few generations, in contrast to genetic variation.”
This means that plants, at least, may be able to adapt to a new environment more quickly than scientists had thought. However, Paun warns that these results also imply that trying to save threatened species by relocating them to places like botanical gardens for preservation could backfire. The plants could just as quickly lose the traits that made them so well adapted to their home ecosystem.
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