You are here What is Evolution? In the biological sciences,
evolution is a scientific theory that explains the emergence of
new varieties of living things in the past and in the present;
it is not a "theory of origins" about how life began. Evolution
accounts for the striking patterns of similarities and
differences among living things over time and across habitats
through the action of biological processes such as natural
selection, mutation, symbiosis, gene transfer, and genetic
drift. Evolution has been subjected to scientific testing for
over a century and has been (and continues to be) consistently
confirmed by evidence from a wide range of fields. The National
Center for Science Education is the only national organization
devoted to defending the teaching of evolution in public
schools. This mission is vital because of evolution's central
importance to the conceptual foundations of the modern
biomedical, life, and earth sciences. How to Learn about
Evolution There are many excellent sources of basic bac