How much of your life do you spend thinking about time? Time comes in different forms in geology, mainly absolute and relative.
Perhaps the most widely used evidence for the Theory of Evolution through Natural Selection is the fossil record.
The fossil record may be incomplete and may never fully completed, but there are still many clues to evolution and how it happens within the fossil record.
Below is a chart of commonly used radiometric isotopes, their half-lives, and the daughter isotopes they decay into.
Let's say you found a fossil you think to be a human skeleton.
One way that helps scientists place fossils into the correct era on the Geologic Time Scale is by using radiometric dating.