Not necessarily literally (at least in the early chapters), but most certainly in a figurative sense. Take the fabled chimera as one example. First mentioned by Homer in the Iliad, the chimera is a fire breathing lion in the front, a goat in the middle and a snake for a tail. Kaplan ponders how such a “morphological mess” could be imagined by the ancient Greeks. He eliminates any possible genetic mutations or atavisms and discusses the possible origins of the beast as a collection of mixed species fossils before settling on remains from a tar pit. The problem of there being no tar pits in Greece is resolved by noting that the Greeks had colonies on the Black Sea, which has oil reserves required for a tar pit. Conclusive? Certainly not, but a viable theory that also explains the origins of other hybrid creatures such as the pegasus or sphinx.