The study "The Evolution of the Human Breast" (2001) proposed that the rounded shape of a woman's breast evolved to prevent the sucking infant offspring from suffocating while feeding at the teat; that is, because of the human infant's small jaw, which did not project from the face to reach the nipple, he or she might block the nostrils against the mother's breast if it were of a flatter form (cf. common chimpanzee). Theoretically, as the human jaw receded into the face, the woman's body compensated with round breasts.