Man's ancestor was slow to grow up, just like gorillas

One of our closest ancestors had more in common with gorillas than previously thought, with males of the species taking far longer to reach maturity than females, scientists said yesterday.

Males of Paranthropus robustus - an extinct relative of humans that lived almost 2 million years ago - continued to grow well into adulthood, before a lucky few finally established "harems" of females for breeding.

The result was a big difference in size between males and females.