"You can't make a monkey out of us": Galen and genetics versus Darwin.

The views on the biological relationship between human and ape are polarized. One end is summarized by the axiom that "man is the third chimpanzee", a thesis put forward in an indirect way initially by Charles Darwin in the 19th century. The other is a very modern concept that although similar, the human and ape genomes are distinctly different. We have compared these two views on the subject with the stance of the ancient medical writer Galen. There is a striking resemblance between current and ancient opinion on three key issues. Firstly, on the fact that man and apes are similar but not identical. Secondly, on the influence of such debates on fields much wider than biology. And finally, on the comparative usefulness of apes as a substitute for human anatomy and physiology studies.