(Press-News.org) A team of scientists has pieced together how the hominid Australopithecus sediba (Au. sediba) walked, chewed, and moved nearly two million years ago. Their research, which appears in six papers in the latest issue of the journal Science, also shows that Au. sediba had a notable feature that differed from that of modern humans—a functionally longer and more flexible lower back.
Together, the studies offer a comprehensive depiction of some of the most complete early human ancestral remains ever discovered.
Since its discovery in August 2008, the site of Malapa—located about 30 miles northwest of Johannesburg—has yielded more than 220 bones of early hominins representing more than five individuals, including the remains of babies, juveniles, and adults. The evidence published in Science is based on two individuals from the site. The fossils from the site date to 1.977 to 1.98 million years in age.
"The abundance and remarkable preservation of fossils from Malapa provide unique insights into the way this fascinating extinct species interacted with and moved around in its environment," said New York University anthropologist Scott Williams, the lead author of one of the six papers appearing in Science.
Williams, part of NYU's Center for the Study of Human Origins, and his colleagues authored a paper describing Au. sediba's vertebral column. The work is the first to analyze elements of the cervical, thoracic, lumbar, and sacral regions of the vertebral column in Au. sediba. Their analysis was based on partially complete spines of the two Au. sediba skeletons.
Their study reveals that Au. sediba had a human-like curvature of the lower back, but it was functionally longer and more flexible than that of modern humans.
"They probably walked in a way that we might find strange—a 'compromise' form of bipedalism indicative of a hominin that still partially relied on climbing trees," Williams explained.
He noted that "the adult female is the first early hominin skeleton that preserves an intact terminal thoracic region and this provides critical information on the transition in inter-vertebral joints, and, by inference, mobility of the lower back."
"The bony spine of Au. sediba likely had the same number of vertebrae as that of modern humans," Williams added. "However, it differed in one primary aspect of its configuration—the transition in inter-vertebral articular facets occurred at a higher level of the spine that than normally occurs in modern humans. In combination with other features, a functionally longer lower back would have allowed for a more flexible spine in Au. sediba relative to that of modern humans."
In addition, morphological indicators of strong lumbar curvature suggest that Au. sediba evolved in this regard relative to Au. africanus, which lived between 3.03 and 2.04 million years ago, and closer to the more recent Nariokotome Homo erectus skeleton—to date, the most complete early human skeleton discovered.
The research was conducted at the Evolutionary Studies Institute (ESI) at the University of the Witwatersrand (Wits) in South Africa, where Au. sebida's remains were discovered in 2008.
Overall, the fossils provide an "unprecedented insight into the anatomy and phylogenetic position of an early human ancestor," observed Professor Lee Berger, the project leader from the Wits Evolutionary Studies Institute. "This examination of a large number of associated, often complete and undistorted elements, gives us a glimpse of a hominin species that appears to be mosaic in its anatomy and that presents a suite of functional complexes that are both different from that predicted for other australopiths, as well as that for early Homo.
"Such clear insight into the anatomy of an early hominin species will clearly have implications for interpreting the evolutionary processes that affected the mode and tempo of hominin evolution and the interpretation of the anatomy of less well preserved species."
###
For images, background material, audio or video clips, download the media pack from http://www.wits.ac.za or contact: Vivienne Rowland, Senior Communications Officer, University of the Witwatersrand, Johannesburg: +27-11-717-1017 (tel.), +27-83-395-1239 (cell), vivienne.rowland@wits.ac.za.
New research reveals how human ancestor walked, chewed, and moved
2013-04-12
ELSE PRESS RELEASES FROM THIS DATE:
Molecular techniques are man's new best friend in pet obesity research
2013-04-12
CHAMPAIGN, Ill. — According to the World Health Organization, more than two-thirds of Americans are overweight or obese. And it's not just humans who are packing on the pounds. Our furry companions are plagued by an obesity epidemic of their own. More than 50 percent of the dogs and cats in the United States are overweight or obese.
In a new paper on pet obesity in the Journal of Animal Science, University of Illinois professor of animal and nutritional sciences Kelly Swanson and his colleagues describe how nutrients and biological compounds in foods can affect gene expression ...
How Alzheimer's could occur
2013-04-12
A new hypothesis has been developed by researchers in Bochum on how Alzheimer's disease could occur. They analysed the interaction of the proteins FE65 and BLM that regulate cell division. In the cell culture model, they discovered spherical structures in the nucleus that contained FE65 and BLM. The interaction of the proteins triggered a wrong signal for cell division. This may explain the degeneration and death of nerve cells in Alzheimer's patients. The team led by Dr. Thorsten Müller and Prof. Dr. Katrin Marcus from the Department of Functional Proteomics in cooperation ...
NASA sees sun emit an M6.5 flare
2013-04-12
The M6.5 flare on the morning of April 11, 2013, was also associated with an Earth-directed coronal mass ejection (CME), another solar phenomenon that can send billions of tons of solar particles into space and can reach Earth one to three days later. CMEs can affect electronic systems in satellites and on the ground. Experimental NASA research models show that the CME began at 3:36 a.m. EDT on April 11, leaving the sun at over 600 miles per second.
Earth-directed CMEs can cause a space weather phenomenon called a geomagnetic storm, which occurs when they connect with ...
NASA satellite image sees Cyclone Victoria looking like a 'J' from space
2013-04-12
When NASA's Aqua satellite flew over Cyclone Victoria in the Southern Indian Ocean it captured a visible image of the storm and it appeared to look like the letter "J." A band of thunderstorms wrapping into the center from the east of low-level center of circulation extended north, creating the appearance of the letter.
NASA's Aqua satellite passed over Tropical Cyclone Victoria on April 11 at 0320 UTC (April 10 at 11:20 p.m. EDT). The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard Aqua captured the visible image that showed strong thunderstorms ...
Why we buy music
2013-04-12
A new study reveals what happens in our brain when we decide to purchase a piece of music when we hear it for the first time. The study, conducted at the Montreal Neurological Institute and Hospital – The Neuro, McGill University and published in the journal Science on April 12, pinpoints the specific brain activity that makes new music rewarding and predicts the decision to purchase music.
Participants in the study listened to 60 previously unheard music excerpts while undergoing functional resonance imaging (fMRI) scanning, providing bids of how much they were willing ...
Ice cloud heralds fall at Titan's south pole
2013-04-12
An ice cloud taking shape over Titan's south pole is the latest sign that the change of seasons is setting off a cascade of radical changes in the atmosphere of Saturn's largest moon. Made from an unknown ice, this type of cloud has long hung over Titan's north pole, where it is now fading, according to observations made by the Composite Infrared Spectrometer (CIRS) on NASA's Cassini spacecraft.
"We associate this particular kind of ice cloud with winter weather on Titan, and this is the first time we have detected it anywhere but the north pole," said the study's lead ...
UCLA study suggests potential therapy for HIV
2013-04-12
UCLA scientists have shown that temporarily blocking a protein critical to immune response actually helps the body clear itself of chronic infection. Published in the April 12 edition of Science, the finding suggests new approaches to treating persistent viral infections like HIV and hepatitis C.
The research team studied type-1 interferons (IFN-1), proteins released by cells in response to disease-causing organisms that enable cells to talk to each other and orchestrate an immune response against infection. Constant IFN-1 signaling is also a trademark of chronic viral ...
ACP and FSMB encourage doctors to 'pause before posting' and not 'friend' patients in policy paper
2013-04-12
April 11, 2013 -- The creation and use of information online and the widespread use of the Internet offer exciting new opportunities for patient care, but also require physicians to consider how to best protect patient interests and apply principles of professionalism to online settings, the American College of Physicians (ACP) and the Federation of State Medical Boards (FSMB) said today in a newly released policy paper, "Online Medical Professionalism: Patient and Public Relationships."
"Digital communications and social media use continue to increase in popularity among ...
New research helps place modern temperatures into a more complete statistical framework
2013-04-12
Harvard researchers are adding statistical nuance to our understanding of how modern and historical temperatures compare.
Through developing a statistical model of Arctic temperature and how it relates to instrumental and proxy records derived from trees, ice cores, and lake sediments, Martin Tingley, a research associate in Harvard's Department of Earth and Planetary Sciences and Peter Huybers, Professor of Earth and Planetary Sciences, have shown that the warmest summers in the last two decades are unprecedented in the previous six centuries. Their work is described ...
Most effective PTSD therapies are not being widely used, researchers find
2013-04-12
Post-traumatic stress disorder affects nearly 8 million adults in any given year, federal statistics show. Fortunately, clinical research has identified certain psychological interventions that effectively ameliorate the symptoms of PTSD. But most people struggling with PTSD don't receive those treatments, according to a new report published in Psychological Science in the Public Interest.
In the report, internationally renowned trauma expert Edna Foa of the University of Pennsylvania and a team of distinguished psychological scientists review studies describing interventions ...