Humanity’s most complete hominid skeleton ever found to date, a bipedal dubbed “Lucy”, appears to have spent a lot of time in the trees, announced researchers Wednesday.
The latest installment to a years-old debate was published in the scientific journal PLoS One, suggesting that Lucy had likely been hanging from trees due to her extremely powerful arms.
This notion comes despite the fact that Lucy was also bipedal, meaning she has characteristics that enabled her to walk upright the way modern humans do.
The 3.2-million-year-old Australopithecus portrays evidence of both bipedalism, such as her long legs and bent knees, and a more arboreal lifestyle, as indicated by her long arms and curved, chimp-like fingers.
So What Was She?
Lead author Christopher Ruff, a biological anthropologist at Johns Hopkins School of Medicine, said “This is what makes Lucy so fascinating. She had crossed a lot of thresholds on the path to becoming human, but not all of them.
“We have to look at traits that changed during her life depending on how she used that part of her skeleton — that’s real evidence of what someone was actually doing.”
Ruff admitted that the features could be a result of primitive retention, or characteristics that stay in organisms well after they are no longer being used.
However, CT scans taken at the University of Texas in 2008 showed evidence of heavy use of the arms, likely due to tree-climbing.
“We know she was not playing tennis.”
Ruff explained that heavy use of a bone results in “strength characteristics”, and these features can be seen on the skeleton using micro CT scans.
Researchers at the University of texas took cross sections of Lucy’s, humeri, or upper arm bones, and her left femur, comparing it to those of a modern human’s. They found that Lucy portrayed significant strength characteristics- not as much as chimps, but significantly more than a human.