In an article published in the June 7, 2018 issue of The New York Review of Books, authors Israel Rosenfield and Edward Ziff discussed epigenesis, “a newly recognized genetic mechanism . . . which enables the environment to make long-lasting changes in the way genes are expressed.”
Without changing the information encoded in the DNA, epigenesis changes the manner in which the genes are “read.” This could result in both beneficial and adverse phenotypic changes. Surprisingly, in some cases such alterations can “be passed on to future generations who have never directly experienced the stresses that caused their forebears’ depression or ill health,” the authors noted. Multiple external influences can act as triggers of adverse epigenetic changes, including stress, childhood trauma, and malnourishment, but also, what is increasingly recognized, exposure to toxicants.
Israel Rosenfield and Edward Ziff (2018). “Epigenetics: The evolution revolution.” The New York Review of Books, issue June 7, 2018.