Environmental Stresses Left Marks on Ancient Genes

AUSTIN, TEXAS—Chemical modifications, known as epigenetic marks, can be added to or removed from a person’s DNA in response to environmental factors such as diet, disease, and climate. These changes can influence which genes are turned on or off during a person’s life, shaping physical traits and health, and can even be passed on to offspring if the changes occur in sperm and egg DNA. Anthropologists from The University of Texas at Austin have shown that epigenetic marks on DNA can be detected in ancient human remains using techniques that are normally used to measure changes in modern DNA. They looked for an epigenetic mark known as cytosine methylation on the remains of 30 individuals who lived in five different places in North America between 230 to more than 4,500 years ago. They were able to identify methylation in 29 of the samples. “By studying methylation in ancient DNA from archaeological populations, not just isolated samples, we may gain insights into how past environments affected ancient societies. Future research in ancient epigenetics should open a new window into the lives and experiences of people who lived long ago,” anthropologist Deborah Bolnick explained in a press release. To read about the first people to reach the New World, see “America, in the Beginning.”