 Darwin was initially reluctant to publish on human origins. While he did not discuss human evolution in his Origin of Species, he promised, “Light will be thrown on the origin of man and his history” (1859: 487). Huxley (1863) wrote Man’s Place in Nature, the first book on human evolution from a Darwinian point of view which discussed fossil evidence, such as the then recently uncovered Neanderthal fossils from Gibraltar. Darwin’s (1871) Descent of Man identified Africa as the likely place where humans originated, and used comparative anatomy to demonstrate that chimpanzees and gorillas were closely related to humans. In the twentieth century, paleoanthropologists debated whether humans separated from the other great apes (at the time wrongly classified into the paraphyletic group Pongidae) about 15 million years ago, or about 5 million years ago. Molecular clocks—first immune responses (e.g., Sarich &amp; Wilson 1967), then direct genetic evidence (e.g., Rieux et al. 2014)—favor the shorter chronology.