Evidence is mounting that epigenetic marks on DNA can influence future generations in a variety of ways. But how such phenomena might affect large-scale evolutionary processes is hotly debated.
In mice, epigenetic marks made on histones during infancy influence depression-like behavior during adulthood. A drug that reverses the genomic tags appears to undo the damage.
The concept of epigenetic inheritance has long been controversial. Some researchers hope that new data on cross-generational effects of environmental exposures will help settle the debate.