An increasing number of studies have been linking experiences of parents — especially rodent parents — to the health of their offspring and even ensuing generations. For instance, as Angela Saini at the Observer writes, researchers have found that mice on a restricted diet during pregnancy not only had pups that were smaller and at a heightened risk of diabetes later in life, but offspring born to those pups were also smaller with an increased risk of diabetes.
Epigenetics, Saini writes, may explain how these extra-genetic characteristics are passed between generations. "For decades, we have thought of our offspring as blank slates," she says. "Now, epigeneticists are asking whether in fact our environment, from smoking and diet to pollution and war, can leave 'epigenetic marks' on our DNA that could get passed on to subsequent generations."
Researchers, she adds, are also investigating whether and how such epigenetic inheritance occurs in people.
However, some scientists say that enthusiasm for epigenetics is obscuring the tenuous nature of some of the results published thus far. "Journals are very excited about this. They want to publish this stuff. But we must be more cautious," says Anne Ferguson-Smith from the University of Cambridge, noting that the mechanism of how epigenetic marks could be passed between generations is not clear.