II.

Classification

Homo sapiens is identified, for purposes of classification, as an animal (kingdom Animalia) with a backbone (phylum Chordata) and segmented spinal cord (subphylum Vertebrata) that suckles its young (class Mammalia); that gestates its young with the aid of a placenta (subclass Eutheria); that is equipped with five-digited extremities, a collarbone, and a single pair of mammary glands on the chest (order Primates); and that has eyes at the front of the head, stereoscopic vision, and a proportionately large brain (suborder Anthropoidea). The species belongs to the family Hominidae, the general characteristics of which are discussed below.