By Bruce Bower
The ancient hominid known as Lucy is getting shouldered into the trees by a recently uncovered fossil child. But scientific onlookers disagree about whether Lucy’s long-extinct species mixed tree climbing with walking.
Apelike shoulder blades from the ancient skeleton of a roughly 3-year-old girl that belonged to Australopithecus afarensis — the same species as Lucy, a famous 3.2-million-year-old partial female skeleton found in 1974 — suggest that these early members of the human evolutionary family split time between scrambling up trees and walking on the ground, say paleobiologist David Green of Midwestern University in Downers Grove, Ill., and anthropologist Zeresenay Alemseged of the California Academy of Sciences in San Francisco.
Scientists have argued for more than 30 years about whether A. afarensis was built mainly for walking or possessed physical attributes suitable for ascending trees as well. Shoulder blades of a fossil child discovered in 2000 in Dikika, Ethiopia, indicate that Lucy’s crew could indeed scale trees beginning early in life, Green and Alemseged report in the Oct. 26 Science.