How Do We Know How Long It Took to Grow Up?

How Do We Know How Long It Took to Grow Up?

As teeth develop, new enamel layers form daily. Scientists used CT-scanning to count the enamel layers on teeth of a Homo sapiens child who lived in northern Africa 160,000 years ago.

The layers show that the teeth were growing and erupting at the same rate as those of seven- to eight-year-old children today, telling us that this fossil human child was growing at the same rate as living humans.

Image of emanel layers on teeth of a Homo sapiens child who lived 160,000 years ago.

  CT scan of emanel layers on teeth of a Homo sapiens child who lived 160,000 years ago.