Courtesy of Zeresenay Alemseged, Dikika Research ProjectThe fossilized shoulder blades of a 3.3 million-year-old hominin, Australopithecus afarensis, suggest that it spent a lot of time climbing trees, despite being able to walk upright. The new evidence, published today (October 25) in Science, adds fuel to a 30-year-old debate over whether these direct ancestors of Homo species abandoned their forest canopy retreats to spend their lives on the ground—and the heated discussion continues.
“This contribution adds usefully to the growing evidence that early hominins remained partially arboreal or at least retained 'arboreal adaptations' for a long time,” primate evolutionary biologist Robin Huw Crompton of the University of Liverpool wrote in an email to The Scientist.
Australopithecus afarensis’s anatomy falls halfway between that of an ape and that of a human, and the species “is a testament to the progressive, gradual process of evolution,” said senior author Zeresenay Alemseged, an anthropologist at the California Academy of Sciences.
The new data come from a 3.3 million-year-old skeleton of a 3-year old girl, known as “Selam,” which Alemseged discovered in 2000 in Dikika, Ethiopia. After spending 11 years painstakingly extracting the skeleton from sandstone, Alemseged and his collaborator, anatomist David Green ...
