Embryos appear to reverse their biological clock early in development

In mice, a ‘rejuvenation event’ wipes out genetic signs of aging days after fertilization

a magnified image of an egg cell surrounded by sperm

A study suggests that the biological age of both mouse and human embryos resets during development. Here, a human egg is illustrated surrounded by sperm.

KATERYNA KON/SCIENCE PHOTO LIBRARY

As people age, so do all of our cells, which accumulate damage over time.