viernes, 22 de abril de 2011

Is This Fossil a New Species of Humans? Some Experts Say "Yes"

Is This Fossil a New Species of Humans? Some Experts Say "Yes"


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This spooky image shows the  controversial cranium of Malapa Hominid 1, Holotype of Australopithecus sediba unearthed in April 2010 in a South African cave. Fossils of the bones of the young male and  adult female suggests a controversial new species,  that walked upright and shared many physical traits with the earliest known human Homo species.


Lee Berger from the University of the Witwatersrand and his team discovered the skeletal remains of the two specimens they determined to be a new species of human. The two partial skeletons may belong to a previously unclassified species of pre-human dating back almost 2 million years and may shed new light on human evolution.


The finding of the pre-human, or hominid, fossils -- which scientists say are between 1.78 and 1.95 million years old -- was published in the journal Science and where believed to possibly answer some key questions about where humans came from.


The skeletons had characteristics of previous species of Australopithecus, but also of Homo, leading the researchers to believe they may have found an evolutionary connection between the two, which evolved into a classic academic battle, with many believing there was no connection to Homo and that what they had discovered was really an ancestor of later Homo species.

At the annual meeting of the Paleoanthropology Society on April 12 and again on April 16 at the annual meeting of the American Association of Physical Anthropologists, Berger and his team presented new findings on their most recent bone analysis.

Kristian J. Carlson discussed the size and shape of A. sediba's brain, showing that by synchrotron scanning of the interior brain case, they were able to determine the estimated capacity to be around 420 cubic centimeters, which led to a very small brain size and is the reason researchers first determined these new skeletal findings to be in the Australopithecus genus.

However, they also discovered that the frontal lobe of this small brain contained organization more similar to that of humans, showing that contrary to what was previously thought, organization and brain size with human characteristics may not have been a simultaneous change. The pelvis of the A. sediba is what researchers believe show the strongest link toward the beginning of an evolutionary change to the Homo.

Researchers have always linked the larger brain size of the Homo to the evolutionary change in the pelvic structure between the two. However, even with the small brain size and cranial structure of A. sediba, the pelvic structure has changed from previous Australopithecus to much closer to that of Homo.


Provided by The Daily Galaxy 
Image credit: Photo by Brett Eloff, courtesy Lee Berger and the University of the Witwatersrand.