ISTOCK, BESTDESIGNSDNA methylation—changes to the activity of a DNA segment without changing the sequence—may be a rich source of raw material for natural selection, say the authors of a new study that analyzed DNA methylation, genotype, and gene expression data from five diverse human populations. They found that population-wide epigenetic changes happen much faster than changes in the DNA sequence.
The result, published August 28 in Nature Ecology & Evolution, may offer insight into how human populations respond to environmental pressures via epigenetic responses.
The epigenome is at the interface between the genome and the environment, so studying it offers clues about different ways in which human populations respond to their surroundings, says Lluis Quintana-Murci, a human evolutionary geneticist at the Pasteur Institute in Paris who was not involved in the study. One way to adapt is through DNA sequence variation, which can be the substrate of natural selection. For instance, a mutation conferring increased resistance to malaria can increase in frequency in a given population through positive selection. But populations can respond, or possibly adapt, to environmental challenges through DNA methylation variation, too. When ...
