Early human ancestors were still climbing trees three million years ago, according to a new study which contradicts previous assumptions that they spent most of their lives on the ground.
Fossilised shoulder bones from a forerunner of humans known as Australopithecus afarensis , the species of the famous "Lucy" skeleton, suggest that their bodies were shaped by a life spent clinging on to branches with their hands.
From the shape of the species' feet it has long been clear that they could walk on two legs, but experts have been unable to prove whether, like their contemporary apelike species, they also spent part of their lives in trees.
A study published last year claimed that A. afarensis's foot structure was ill-suited to grasping branches and showed that by this stage in human evolution, our ancestors had already abandoned climbing behaviour.
But the new research, by experts from the
California Academy of Sciences and
Midwestern University, suggests that the transition from trees to a permanent life on solid ground occurred later than previously thought...
