Blue wildebeest
This species of wildebeest seems to have evolved around 2.5 million years ago. The black wildebeest is believed to have diverged from the blue wildebeest to become a distinct species around a million years ago, in the mid- to late Pleistocene. Fossil evidence suggests that blue wildebeest were quite common in the Cradle of Humankind in the past. Apart from eastern Africa, fossils are commonly found in Elandsfontein, Cornelia, and Florisbad.
Black wildebeest
The black wildebeest is currently included in the same genus as the blue wildebeest ("Connochaetes taurinus"). This has not always been the case, and at one time the latter was placed under a separate genus of its own, "Gorgon". The black wildebeest lineage seems to have diverged from the blue wildebeest in the mid- to late Pleistocene, and became a distinct species around a million years ago. This evolution is quite recent on a geologic time scale.