 Paleoanthropologists who rejected the classification of SK 847 as "Homo" referred to the single species hypothesis, which states that because of competitive exclusion, two species of hominids could not occupy the same niche.Therefore, all hominids from Swartkrans were of the same species and SK 847 is simply a small robust australopithecine.However, the single species hypothesis is no longer valid or accepted as true by anthropologists.