Sewall Wright, the inventor of Fst (fixation index, a method of measuring genetic differentiation between populations) said "there is no question" that human races should "be considered to be of different subspecies."

Many animal species have lower Fst (less genetic differentiation between subpopulations) than humans.

Humans (5 or 6 subspecies) = ~0.15
African buffalo (5 subspecies) = 0.059

"It does not require a trained anthropologist to classify and array of Englishmen, West Africans, and Chinese with 100% accuracy by features, skin color, and type of hair, in spite of such much variability within each of these groups that every individual can easily be distinguished from every other."