The ancient ancestors of humans were tree dwellers, rather than the often depicted knuckle-dragging apes who slowly raised themselves up and evolved into walking humans, claim North American scientists.

Researchers believe that early human ancestors never used their knuckles to walk like gorillas but evolved from other apes that spent most of their time in trees.

They found that although our wrists were capable of 'knuckle walking', our predecessors were more likely to be hanging in trees.

But a new study, published in the journal Proceedings of the National Academy of Sciences, argues that we were more likely to dwell in trees and came down on two feet.