There are markers that sit on top of DNA and change over the course of one's lifetime, and they can even be passed down to future generations. These "epigenetic" markers alter how genes are expressed — without changing their codes — and they can change based on a person's experiences and environment.
Research suggests that stressful events can tweak a person's epigenetics — but what happens on a larger scale? How do people's epigenetics change, for example, in a population exposed to upheaval or violence multiple times over generations?
