Date:

Chimpanzees Shed Light on Origins of Human Walking

A research team led by Stony Brook University investigating human and chimpanzee locomotion have uncovered unexpected similarities in the way the two species use their upper body during two-legged walking.

The results, reported in Nature Communications , indicate that our early human ancestors, including the famous fossil ‘Lucy’ (a species known as Australopithecus afarensis), may have been able to use their torsos to increase walking efficiency in the same way as modern humans.

- Advertisement -
This image depicts pelvis and ribcage rotations during bipedal locomotion. Despite differences in overall motion, there is as much mobility between the pelvis and ribcage in humans as in chimpanzees, suggesting more human-like abilities in our earliest ancestors than previously thought.  Credit: Nathan Thompson, Lucille Betti-Nash, and Deming Yang.
This image depicts pelvis and ribcage rotations during bipedal locomotion. Despite differences in overall motion, there is as much mobility between the pelvis and ribcage in humans as in chimpanzees, suggesting more human-like abilities in our earliest ancestors than previously thought. Credit: Nathan Thompson, Lucille Betti-Nash, and Deming Yang.

The torso (the part of the body that includes the ribcage, belly and pelvis) of chimpanzees has long been thought to be a rigid block, best suited for a life of tree climbing. Humans, on the other hand, have long and flexible torsos that aid in walking by allowing us to rotate our upper body in the opposite direction of our lower body. The findings from the paper, titled “Surprising trunk rotational capabilities in chimpanzees and implications for bipedal walking proficiency in early humans,” changes the evolutionary view of how early human ancestors walked and what they were able to do.

“During walking, we actually observed as much rotation within the torsos of chimpanzees as in humans,” said Nathan Thompson, lead author and a PhD student in the Department of Anatomical Sciences at Stony Brook University. “This means that the widely accepted assumptions in the scientific community about how the chimpanzee torso works based on the skeleton alone are incorrect. Our results also point to the notion that a limitation to upright walking that we thought affected Lucy and other early human ancestors probably was not a limitation at all.”

The research team used high-speed cameras to track and compare how the torsos of humans and chimpanzees actually moved during bipedal walking. They studied the movements by way of three-dimensional kinematic analyses and computer-generated comparisons.

They discovered that the main difference between human and chimpanzee bipedalism is that chimps swing their hips much more.

- Advertisement -

“Only when our early ancestors were able to reduce this hip rotation were their upper bodies able to play a human-like role in promoting efficient bipedal walking,” said Thompson. “When this actual transition occurred is still an open question.”

There is a continuing debate about how the hips of our ancestors worked compared to ours.

“For instance, depending on who you ask, the 3.2 million-year-old Lucy fossil either rotated her pelvis exactly like modern humans or up to 2.5 times more,” he explained.

Given this uncertainty, the research team modeled the transition from a more chimp-like pattern of the upper body movement to that of a more human-like pattern. They found that even if Lucy rotated her pelvis 50 percent more than modern humans, her upper body would have functioned essentially like ours. This means that even as early as 3.2 million years ago Lucy might have been able to save work and energy in much the same way as humans do today.

“As we get a better idea of how our closest living relatives move, we are able to learn much more about the isolated piles of early human bones that the fossil record leaves us,” added Thompson. “Only then can we paint a complete picture of how we evolved into what we are today.”

Co-authors on the paper include Susan Larson, Brigitte Demes, and Nicholas Holowka of Stony Brook University, and Matthew C. O’Neill of the University of Arizona.

STONY BROOK UNIVERSITY

 

 

- Advertisement -

Stay Updated: Follow us on iOS, Android, Google News, Facebook, Instagram, Twitter, Threads, TikTok, LinkedIn, and our newsletter

spot_img
Mark Milligan
Mark Milligan
Mark Milligan is a multi-award-winning journalist and the Managing Editor at HeritageDaily. His background is in archaeology and computer science, having written over 8,000 articles across several online publications. Mark is a member of the Association of British Science Writers (ABSW), the World Federation of Science Journalists, and in 2023 was the recipient of the British Citizen Award for Education, the BCA Medal of Honour, and the UK Prime Minister's Points of Light Award.
spot_img
spot_img

Mobile Application

spot_img

Related Articles

Soldier’s wrist purse discovered at Roman legionary camp

Archaeologists have discovered a fragment of a soldier's wrist purse at the site of a temporary Roman camp in South Moravia, Czech Republic.

Lost equestrian sculpture found buried in Toul

Archaeologists from the National Institute for Preventive Archaeological Research (Inrap) have discovered an equestrian sculpture during excavations in Toul, France.

Roman-Era settlement unearthed in Alès

A recent excavation led by Inrap has uncovered a remarkably well-preserved Roman-era settlement on the slopes of the Hermitage hill overlooking Alès, southern France.

Excavations in Olympos reveal ancient mosaics and sacred inscriptions

Excavations in Olympos, Antalya province, have uncovered mosaic floors and inscriptions within a 5th-century church, part of a year-round project backed by Türkiye’s Ministry of Culture and Tourism.

Mammoth bones uncovered during road construction works

The Construction of the S17 Piaski–Hrebenne highway near the Arabunie village in Zamość County has revealed the remains of what is believed to be either a woolly mammoth or a forest elephant.

Hidden Medieval tower unearthed in Lublin reveals forgotten chapter of city’s past

Archaeologists have uncovered the remains of a previously undocumented medieval tower within the grounds of the former Pobernardine monastery complex, near the Church of the Conversion of Saint Paul on Bernardyńska Street.

Sinkhole reveals lost remains of medieval hospital

A sinkhole that formed outside the York Theatre Royal has led to the discovery of what could be one of England’s largest medieval hospitals.

Chalcolithic cultural treasures unearthed in Caucasus

Archaeologists from the Institute of Archaeology of the Russian Academy of Sciences have uncovered 13 Chalcolithic-era sites, each yielding a wealth of cultural artefacts and material evidence.