Time of onset of sperm production in boys

Abstract

Puberty is defined in the Oxford English Dictionary as the state or condition of having become functionally capable of procreating offspring, suggesting that it is a discrete event that occurs at a particular point in time. Whilst it is easy to determine the age at puberty in animals from the time of completion of spermatogenesis in the male, or the first ovulation in the female, these are particularly difficult criteria to evaluate in our own species. Thus human puberty is generally described in terms of a sequence of changes in secondary sexual characteristics occurring over an extended period of time, and these have been reviewed in detail by Marshall & Tanner (1974).