AUSTIN, Texas // Scientists working on the fossil bones of the ancient human ancestor from Ethiopia dubbed Lucy determined that she was adept at climbing trees and walking.
Researchers last week announced the results of an intensive analysis of the 3.18-million-year-old fossils of Lucy, a member of a species early in the human evolutionary lineage known as Australopithecus afarensis.
Scans of Lucy’s arm bones showed they were heavily built, like those of chimpanzees, indicating this species spent significant time climbing in trees and used their arms to pull themselves up in the branches.
Australopithecus afarensis had a combination of apelike and human-like traits. Scientists knew its feet were adapted for walking upright on two legs but wondered if it still spent time in trees. The researchers performed high-resolution scans on Lucy’s fossils at the University of Texas and compared the findings to data on the bones of modern humans and chimpanzees.
“The debate about whether or not Lucy climbed trees has raged since her discovery 42 years ago and our study brings that debate to a close,” said John Kappelman, University of Texas palaeoanthropologist. The study was published in the journal Plos One.
The 1974 discovery of Lucy shed light on early stages of human evolution. Our species, Homo sapiens, appeared in Africa 200,000 years ago.
“Our analysis required well-preserved upper and lower limb bones from the same individual, something very rare,” said the study’s lead author Christopher Ruff, professor of functional anatomy and evolution at Johns Hopkins University School of Medicine.
The findings fit nicely with a study published in August by Dr Kappelman and other researchers that based on fractures in the fossils, said Lucy may have died after a fall from a tree.
Dr Kappelman hypothesised that Lucy, about 1.07 metres tall, foraged on the ground and sought nightly refuge in trees. Her injuries indicated she fell from a height of more than 12m.
“It may seem unique from our perspective that early hominins like Lucy combined walking on the ground on two legs with a significant amount of tree climbing, but Lucy didn’t know she was unique,” he said.
* Reuters