Featured Research

from universities, journals, and other organizations

Walk this way: New research suggests human ancestors may have used different forms of bipedalism during the plio-pleistocene

Date:
April 11, 2013
Source:
Boston University College of Arts & Sciences
Summary:
According to a new study, our Australopithecus ancestors may have used different approaches to getting around on two feet. The new findings represent the culmination of more than four years of research into the anatomy of Australopithecus sediba (Au. sediba). The two-million-year-old fossils, discovered in Malapa cave in South Africa in 2008, are some of the most complete early human ancestral remains ever found.

BU anthropologist Jeremy DeSilva with Au. sediba skull.
Credit: Boston University

According to a new study, our Australopithecus ancestors may have used different approaches to getting around on two feet. The new findings, co-authored by Boston University researchers Jeremy DeSilva , assistant professor of anthropology, and Kenneth Holt, assistant professor of physical therapy, appear in the latest issue of the journal Science in an article titled "The Lower Limb and Mechanics of Walking in Australopithecus sediba." The paper is one of six published this week in Science that represent the culmination of more than four years of research into the anatomy of Australopithecus sediba (Au. sediba). The two-million-year-old fossils, discovered in Malapa cave in South Africa in 2008, are some of the most complete early human ancestral remains ever discovered.

The locomotion findings are based on two Malapa Au. sediba skeletons. The relatively complete skeletons of an adult female and juvenile male made possible a detailed locomotor analysis, which was used to form a comprehensive picture of how this early human ancestor walked around its world.

The researchers hypothesize this species walked with a fully extended leg (like humans do), but with an inverted foot (like an ape), producing hyperpronation of the foot and excessive rotation of the knee and hip during bipedal walking. These bipedal mechanics are different from those often reconstructed for other australopiths and suggest that there may have been several forms of bipedalism throughout human evolution.

Australopithecus sediba has a combination of primitive and derived features in the hand, upper limb, thorax, spine, and foot. It also has a relatively small brain, a human-like pelvis, and a mosaic of Homo- and Australopithecus-like craniodental anatomy. The foot in particular possesses an anatomical mosaic not present in either Au. afarensis or Au. africanus, supporting the contention that there were multiple forms of bipedal locomotion in the Plio-Pleistocene. (The recent discovery of an Ardipithecus-like foot from 3.4-million-year-old deposits at Burtele, Ethiopia, further shows that at least two different forms of bipedalism coexisted in the Pliocene.)

"Our interpretation of the Malapa skeletal morphology extends the variation in Australopithecus locomotion," says DeSilva. "As others have suggested, there were different kinematic solutions for being a bipedal hominin in the Plio-Pleistocene. The mode of locomotion suggested by the Malapa skeletons indicates a compromise between an animal that is adapted for extended knee bipedalism and one that either still had an arboreal component or had re-evolved a more arboreal lifestyle from a more terrestrial ancestor." DeSilva adds that there is some evidence that the South African species Au. africanus may have been more arboreal than the east African Au. afarensis. "A hypothesized close relationship between Au. africanus and Au. sediba, along with features in the upper limbs of the latter thought to reflect adaptations to climbing and suspension, is consistent with a retained arboreal component in the locomotor repertoire of Au. sediba."

Co-authors of this study are Kristian J. Carlson, Evolutionary Studies Institute, University of the Witwatersrand, South Africa and the Department of Anthropology, Indiana University, Bloomington, IN; Christopher S. Walker, Department of Evolutionary Anthropology, Duke University, Durham, NC; Bernhard Zipfel, Evolutionary Studies Institute, University of the Witwatersrand, South Africa and Bernard Price Institute for Palaeontological Research, School of Geosciences, University of the Witwatersrand, , South Africa; and Lee R. Berger, Evolutionary Studies Institute, University of the Witwatersrand, South Africa.


Story Source:

The above story is based on materials provided by Boston University College of Arts & Sciences. Note: Materials may be edited for content and length.


Journal Reference:

  1. J. M. DeSilva, K. G. Holt, S. E. Churchill, K. J. Carlson, C. S. Walker, B. Zipfel, L. R. Berger. The Lower Limb and Mechanics of Walking in Australopithecus sediba. Science, 2013; 340 (6129): 1232999 DOI: 10.1126/science.1232999

Cite This Page:

Boston University College of Arts & Sciences. "Walk this way: New research suggests human ancestors may have used different forms of bipedalism during the plio-pleistocene." ScienceDaily. ScienceDaily, 11 April 2013. <www.sciencedaily.com/releases/2013/04/130411142710.htm>.
Boston University College of Arts & Sciences. (2013, April 11). Walk this way: New research suggests human ancestors may have used different forms of bipedalism during the plio-pleistocene. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2013/04/130411142710.htm
Boston University College of Arts & Sciences. "Walk this way: New research suggests human ancestors may have used different forms of bipedalism during the plio-pleistocene." ScienceDaily. www.sciencedaily.com/releases/2013/04/130411142710.htm (accessed October 21, 2014).

Share This



More Fossils & Ruins News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Fish Fossil Shows First-Ever Sex Was Done Side By Side

Fish Fossil Shows First-Ever Sex Was Done Side By Side

Newsy (Oct. 19, 2014) A 380-million-year-old fish may be the first creature to have copulative sex - and it was side by side with arms linked, like square dancers. Video provided by Newsy
Powered by NewsLook.com
As Sweden Hunts For Sub, "Cold War" Comparisons Flourish

As Sweden Hunts For Sub, "Cold War" Comparisons Flourish

Newsy (Oct. 19, 2014) With Sweden on the look-out for a suspected Russian sub, a lot of people are talking about the Cold War, but is it an apt comparison? Video provided by Newsy
Powered by NewsLook.com
So, Kangaroos Didn't Always Hop

So, Kangaroos Didn't Always Hop

Newsy (Oct. 16, 2014) Researchers believe an extinct kangaroo species weighed 500 pounds or more and couldn't hop. Video provided by Newsy
Powered by NewsLook.com
1000-Year-Old Viking Treasure Hoard Found in Scotland

1000-Year-Old Viking Treasure Hoard Found in Scotland

Reuters - Light News Video Online (Oct. 14, 2014) A hoard of Viking artifacts dating back over 1,000 years is discovered by a treasure hunter with a metal detector in Scotland. Elly Park reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins