Missing link?

From The Sunday Times, April 4, 2010
.

Fossil from cave is a ‘missing

link’

By Brendan Bourne

A FOSSIL skeleton of a child discovered in a cave system known as the Cradle of Humankind may represent a previously unknown stage in the evolution of man.

The skeleton, which is almost complete despite being 2m years old, is believed to belong to one of the hominid groups that includes humans. Hominid fossil finds are usually little more than small bone fragments. Scientists hope such a complete find will help them to work out what our ancestors looked like and to determine key dates in their evolution from ape-man to man-ape. Experts who have seen the skeleton says it resembles Homo habilis, the first species of advanced human.

The skeleton was found by Professor Lee Berger, reader in human evolution and the public understanding of science at the University of the Witwatersrand, South Africa, as he explored cave systems in Sterkfontein, a Unesco world heritage site. The caves are the site of one of the world’s longest-running archeological excavations and are regarded as palaeontological treasure troves. Jacob Zuma, the South African president, has visited the university to view the find, which is to be announced this week.

The new fossil skeleton was found with a number of other partially complete fossils, encased within breccia sedimentary rock inside a limestone cave known as Malapa cave.

Scientists believe that a group of apelike hominids known as australopithecus, which first emerged in Africa around 3.9m years ago, gradually evolved into the first Homo species.

Over time the species lost its more apelike features as it started to stand upright and its brain capacity increased. Around 2.5m years ago Homo habilis, the first species to be described as distinctly human, began to appear, although only a handful of specimens have been found.

It is thought the new fossil will be identified as a species that fits somewhere between australopithecus and Homo habilis.

Dr Simon Underdown, an expert on human evolution at Oxford Brookes University, said: “A find like this could really increase our understanding of our early ancestors at a time when they first started to become recognisable as human.”

The discovery is the most important find from Sterkfontein since an almost complete fossil of a 3.3m-year-old australopithecus was found in 1994.

___________________________________________________________

From The Times, April 5, 2010

Bones in South African cave

establish new link in chain of

mankind

By Hannah Devlin

A species of early human has been discovered in a South African cave, shedding light on a critical period during which our ancestors began to walk upright, use tools and develop a capacity for language.

Scientists say the two million-year-old fossilised skeleton is from a previously unknown type of hominid, the evolutionary branch of primates that led to humans. The new species could be an intermediate stage between ape-like hominids and the first species of advanced humans, Homo habilis.

The child’s skeleton and bones belonging to several adults were found by experts from the University of the Witwatersrand. Lee Berger and his colleagues made the discovery while exploring cave systems in the Sterkfontein area, near Johannesburg.

President Zuma of South Africa has visited the university to view the fossils. But within the scientific community Professor Berger’s team have kept the find under wraps, and only a few scientists have viewed the specimens.

//

Phillip Tobias, an eminent human anatomist and anthropologist at the university, who was one of those who in 1964 identified Homo habilis as a new species of human, said that the latest discovery was exciting.

“To find a skeleton as opposed to a couple of teeth or an arm bone is a rarity,” Professor Tobias said. “It is one thing to find a lower jaw with a couple of teeth, but it is another thing to find the jaw joined to the skull, and those in turn uniting further down with the spinal column, pelvis and the limb bones.

“It is not a single find, but several specimens representing several individuals. The remains now being brought to light by Dr Berger and his team are wonderful.”

Kevin Kuykendall, a palaeoanthropologist at the University of Sheffield, said that the full details of the find were keenly awaited. “According to what is being said, what’s particularly spectacular is that there is a fairly complete skeleton and also specimens from more than one individual,” he said.

If the fossils include pelvis and complete limb bones, scientists would be able to infer the posture and gait used by the extinct species. Hand bones could show the species’ dexterity and capacity for tool use, while the presence or absence of an opposable big toe would indicate whether or not the species had permanently abandoned the trees for land.

The human and chimpanzee ancestral branches diverged six million years ago, and the first upright walking hominids emerged about 3.9 million years ago. However, the fossil record suggests that early hominids continued to spend much of their time in the trees and that it was only about 2.5 million years ago that more sophisticated human-like traits emerged.

Homo habilis, which dates from this period, is the first species to be described as distinctly human, but only a handful of specimens have ever been found, many of which consist of a few scattered bone fragments.

When, and why, our ancestors first adopted a fully bipedal lifestyle and lost features such as an opposable big toe and long ape-like arms remain a contentious issue.

“With my students I talk about hominid evolution and human evolution,” said Simon Underdown, of Oxford Brookes University, a specialist in human evolution. “The question is when do we see the real human traits appearing, when did complex stone tool use and language emerge? This fossil appears to be just on the cusp of that and it could help us fill in that big gap.

“More and more finds are coming out of South Africa. It’s increasingly seen as an important location,” Dr Underdown said.

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~ von Panther Ray - April 4, 2010.

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