Quote Originally Posted by By Will Dunham

Orangutan study suggests early walking on two legs

WASHINGTON (Reuters) - The way orangutans navigate fragile tree branches in search of fruit has led scientists to propose that human ancestors with similar lifestyles may have begun walking on two legs earlier than previously thought.

Three British scientists, writing on Thursday in the journal Science, suggested that bipedal walking arose in arboreal apes 17 to 24 million years ago, rather than between 4 and 8 million years ago as a leading hypothesis indicates.

Upright walking on two legs is seen as a defining human characteristic.

Evolution is cooler than you think.