Those findings apply to a single generation, yet they tug at the edges of evolutionary theory, in which species change slowly over millennia, not rapidly over the months or years of a single life. Charles Darwin’s process of natural selection holds that nature choses the best-adapted organisms to reproduce and survive in any given ecosystem. The process operates when DNA sequences mutate randomly, and organisms with the specific sequences best-adapted to the environment multiply and prevail – causing gene expression to shift. Yet as surely as the slow march of Darwinian evolution shapes life on Earth over aeons, scientists have found that epigenetic signals can work each day, and not just through methyl groups. Experience in the environment could also alter chromatin, the molecular matrix making up our chromosomes; RNA, the messenger molecules that translate genetic instructions from DNA into protein; and histones, the proteins involved in packaging and structuring the chromatin comprising the genes.
Bill Fulkerson on 21 Aug 18"Epigenetic Changes Programmed Into Future Generations But the most disturbing finding was that atrazine had epigenetic effects. Epigenetics is the theory that environmental factors, such as diet, lifestyle choices and pesticides can impact the health of people who are exposed to them and also their descendants. Human DNA, according to epigenetics, is not unchangeable; it can be altered by such environmental factors. Epigenetic changes can be imprinted on the DNA of a fetus during pregnancy according to Winchester."
