The Death That Shapes Us

In the womb, something remarkable happens as a baby's hands take form. At first, the tiny fingers are webbed together — a solid paddle of cells. What creates distinct fingers isn't growth. It's death. Billions of cells between those forming fingers receive a signal and do something extraordinary: they destroy themselves. Biologists call this process apoptosis — from the Greek apoptōsis, meaning "falling off," like leaves releasing from a tree in autumn.…