Ever since recorded history began, and probably before, people have found pieces of rock and other hard material with indentations from the remains of dead organisms. These are called fossils, and the totality of these artifacts and their placement in rock striations is referred to as the fossil record.

The fossil record is one of the primary sources of data relevant to the study of evolution. Scientists examine fossils in order to understand the process of evolution and the way specific species have evolved.

Dating methods, such as radiometric dating (but not carbon-14 dating, which works only for 0-50,000 years before present), show that some of these fossils are tens of millions of years old. Various dating methods have been used and are used today, and while there is some variance in the results from these dating methods, nearly all of them provide evidence for a very old Earth and for evolution.