Fossils provide a record of biological history. They are a source of direct evidence for questions regarding an organism's evolution. Without fossils it is difficult to document phylogeny because there is no way to know the extent of an organism's history or to determine the age of anything. The DNA and the leftover traces of chemicals such as carbon and fluorine in fossils gives essential information about the organism's life, physiological makeup, and environment. Fossils allow for history to be understood chronologically, as records preserved in the earth's strata. Documenting biological evolution relies on the use of fossil evidence because it needs a reliable way to date and classify species and their adaptations over time.
Studying fossils
Studying fossils