In Radford’s work a multigenerational ripple effect was apparently felt after pregnant mice were basically fed a starvation diet for six days late in pregnancy. During that time their standard mouse-chow meals were cut in half. That period of under nutrition coincided with when small collections of atoms, called methyl groups, would typically latch onto sperm DNA and lock genes in the “on” or “off” position in ways that stick with an organism throughout life.