Myth: Evolution is only a theory.

Fact: The occurrence of evolution is a fact; how it occurred is a theory.


Evolution is a fact in that scientists know beyond reasonable doubt that it happened. The exact mechanism of evolution -- that is, exactly how it happened -- is still a theory.


Evolution is both a fact and a theory. Mainstream scientists consider it a fact that evolution occurred; how it occurred is still considered a theory. Stephen J. Gould describes this difference best:

Some nit-pickers might try to argue that nothing can ever be proven 100 percent in science, therefore there is no such thing as a fact, let alone evolution standing as a fact. H.J. Muller tackles this argument: Return to Overview


1. Stephen J. Gould, "Evolution as Fact and Theory," Discover, May 1981. Both quotations have been taken from Larry Moran's FAQ, "Evolution is a Fact and a Theory," which addresses this issue in much greater detail.

2. H. J. Muller, "One Hundred Years Without Darwin Are Enough" School Science and Mathematics 59, (1959) pp. 304-305. Reprinted in Evolution versus Creationism, J. Peter Zetterberg, ed., (ORYX Press, Phoenix AZ 1983).