In the quest to understand how and why early humans started walking on two legs, scientists are now looking to chimpanzees living in dry, open savannah-like environments for clues. A new study reveals that these chimpanzees, despite the open terrain, still frequently climb trees to gather fruit and other foods found high in the canopy. Their behavior suggests that bipedalism may not have evolved purely as a response to ground-based travel, but also for safe and efficient movement within trees.