Study proposes the famed hominin fell to her death 3.18 million years ago.
Lucy the Australopithecus was around 15 years old when she died 3.18 million years ago, in what is now Ethiopia. Just about the size of a five-year-old modern human at the time, her well-preserved bones show a mix of ape-like and human-like traits, sparking debate over whether Lucy was primarily a ground-dweller or an avid tree-climber.
But new research published in the journal Nature proposes that it was a tumble from a tree that left Lucy with nasty compression fractures, and ultimately killed her.
“Lucy has been at the centre of a vigorous debate about the role, if any, of arboreal locomotion in early human evolution,” the authors write. “It is therefore ironic that her death can be attributed to injuries resulting from a fall, probably out of a tall tree, thus offering unusual evidence for the presence of arborealism in this species.”
CT scans of her bones revealed a series of compression fractures, which occur when the hand hits the ground to break the impact of a fall, and this force pushes the bones against each other so hard that parts of the upper arm bone break.
Study lead author John Kappelman, an anthropology and geological sciences professor at the University of Texas at Austin, consulted with an orthopaedic surgeon, who confirmed that the injuries were consistent with a fall from a considerable height. The researchers believe that Lucy was either foraging or sleeping in the tree when she fell from a height of more than 12 meters (40 feet), landing on her feet before falling forward onto her arms, and “death followed swiftly.”
But the science community is far from convinced.
Tim White, a paleoanthropologist at the University of California in Berkeley, tells The Guardian that fossils tend to accumulate damage over time, so these types of cracks are common. “If paleontologists were to apply the same logic and assertion to the many mammals whose fossilised bones have been distorted by geological forces, we would have everything from gazelles to hippos, rhinos, and elephants climbing and falling from high trees,” he says.
"It's an elaborate story," Bernard Wood, a professor of human origins at George Washington University, tells The Washington Post. "It's not science."
Check out this video of Kappelman and other members of the team discussing their research: