Geologists use radiometric dating to estimate how long ago rocks formed, and to infer the ages of fossils contained within those rocks. The universe is full of naturally occurring radioactive elements. Radioactive atoms are inherently unstable; over time, radioactive parent atoms decay into stable daughter atoms.Geologists use radiometric dating to estimate how long ago rocks formed, and to infer the ages of fossils contained within those rocks. The universe is full of naturally occurring radioactive elements

How is radioactive dating used to date fossils?

Radioactive Dating of Fossils Scientists find the ratio of parent isotope to daughter isotope. By comparing this ratio to the half-life logarithmic scale of the parent isotope, they are able to find the age of the rock or fossil in question.

Why is fossil dating important?

Fossils above a specific layer are inferred to be younger than that layer, and those below are older, in line with the law of superposition, a key scientific principle of stratigraphy. Dating of the fossils contributes to a clearer timeline of evolutionary history.