Table 4.

Periods of dependency and times to maturity for selected species.

SpeciesTerm of PregnancySexual MaturityPhysical MaturityTime Span of Female’s Reproductive Life
Human280 days13 years21 years*
Chimpanzee9 years12 years
  • *Women mature by about 18, or even earlier. Some studies have shown that girls are having first menses (menarche) at ages 10 and 11.