3.2 Million-Year-Old Human Ancestor Walked like Us

 

New research using advanced 3D muscle modeling has shed light on our ancient ancestor “Lucy,” who lived 3.2 million years ago.

The findings indicate that Lucy, belonging to the extinct species Australopithecus afarensis, had the ability to stand and walk upright, just like modern humans.

This discovery supports the growing consensus among scientists that Lucy’s species walked in an upright manner rather than adopting a hunched, chimpanzee-like posture.

The analysis of Lucy’s reconstructed pelvis and leg muscles also suggests another intriguing capability: tree climbing.

It appears that Lucy and her kind were skilled climbers, which implies that they thrived in a variety of environments, including both forests and grasslands in East Africa, between 3 to 4 million years ago.

New research suggests that the world's most famous early human ancestor, nicknamed Lucy, could walk fully upright as well as living in trees.
The individual, from the species Australopithecus Afarensis, was discovered in Ethiopia in 1974, with 40% of her skeletal bones. pic.twitter.com/4sG4321wUD

— Ambassador Teferi Melesse Desta 🇪🇹🇬🇧 (@EthioAmbUK) June 14, 2023

Ashleigh Wiseman, a research associate at the McDonald Institute for Archaeological Research at the University of Cambridge in the United Kingdom, conducted the muscle modeling study on Lucy.

Wiseman explains that Lucy’s muscles provide evidence that she possessed the same level of skill in walking upright as modern humans.

Additionally, the research suggests that Lucy was also comfortable in tree-dwelling environments. Wiseman further adds that Lucy would have been capable of effectively utilizing both habitats – the ground and the trees.

Lucy’s fossils are the best-preserved Australopithecus remains

Lucy’s fossils hold a special distinction among Australopithecus remains, as they are remarkably well-preserved.

Unearthed in the Hadar region of Ethiopia in the mid-1970s, these fossils provide valuable insights into our ancient ancestors. Approximately 40% of Lucy’s skeleton was recovered from this excavation, according to Live Science.

In a recent study published on June 14 in the journal Royal Society Open Science, Ashleigh Wiseman employed an innovative digital modeling approach. This method allowed her to recreate and examine 36 muscles in each of Lucy’s legs.

Age 32,00,000 years: the oldest human ancestor uncovered ever. “Lucy” was the first Australopithecus afarensis skeleton found. Discovered in 1974 by paleontologist Donald C. Johanson in Hadar. National Museum of Ethiopia 🇪🇹 pic.twitter.com/mPj4fXvJ8y

— Shahid Choudhary (@listenshahid) March 10, 2023

The reconstruction of Lucy’s muscles indicates that Lucy had the ability to straighten her knee joints and extend her hips, much like modern humans.

So, this suggests that she possessed the capacity to stand and walk upright, a significant characteristic shared with our species.

Lucy’s muscle resembles the bonobo’s in composition

The muscle modeling reveals intriguing details about the composition of Lucy’s legs. Her leg muscles exhibited a distinct proportion of fat and muscle, which differed from that of modern humans.

Moreover, Lucy’s legs were found to be significantly more muscular compared to a typical modern human’s legs. Their composition closely resembled that of the bonobo, a pygmy chimpanzee.

To put it in perspective, while a human thigh consists of approximately 50% muscle, Lucy’s thigh muscles were estimated to be around 74% muscle and less fatty. Additionally, certain calf and thigh muscles took twice as much space in Lucy’s legs as they do in modern human legs.