Hirsutism body hair, particularly in locations where women normally do not develop terminal hair during puberty (chest, abdomen, back, and face). The medical term for excessive hair growth that affects any gender is hypertrichosis. Hirsutism can be caused by either an increased level of androgens, the male hormones, or an oversensitivity of hair follicles to androgens. Male hormones such as testosterone stimulate hair growth, increase size and intensify the growth and pigmentation of hair. Other symptoms associated with a high level of male hormones include acne, deepening of the voice, and increased muscle mass. The condition is called hyperandrogenism. Growing evidence
Neoteny in humans Australia, said that he agrees that neoteny in humans may have become "accelerated" through "two-way sexual selection" whereby females have been choosing smart males as mates and males have been choosing smart females as mates. Neoteny has been important to human evolution, because it has increased the maturation period and the size of the human brain. Two to three million years ago, there was an "incomplete segmental duplication of [the] ancestral SRGAP2" gene in the ancestors of humans. This new gene, SRGAC2, slowed spine maturation and allowed for more neuronal migration. As a result, the dendrite spines increased in number