Two-million-year-old hominid sheds light on evolution

Two skeletons of a new hominid species dating back two million years and found in South Africa have shed light on a previously unknown stage in human evolution, scientists said Thursday.

Baptised Australopithecus sediba, the partially fossilized specimens -- an adult female and a juvenile male -- were found in 2008 in a cavern 40 kilometres (24 miles) from Johannesburg.

"They, ladies and gentlemen, are potentially a Rosetta stone into the past," Lee Berger, a paleo-anthropologist at the University of Witwatersrand, told a press conference at the Cradle of Humankind World Heritage Site.

"They represent a completely new and unexpected species of human ancestor to science. Something we did not think was there."

The 1.9-million-year-old hominids are in "extraordinary condition", would have known each other, and were possibly related. The adult female was aged in her late 20s or early 30s and the boy between 11 and 13, he said.

"What we have found are arguably the most complete early hominid skeletons ever discovered. Each individual is far more complete than the famous Lucy fossil from Ethiopia."

The hominids walked upright and share a number of traits with the first known species of homo sapiens, having long arms like apes but short and powerful hands, according to a paper to be published in the journal Science.

They have evolved pelvises, small teeth and long legs that would enable them to run like a human. It is also probable that they could climb trees.

"Australopithecus sediba appears to present a mosaic of features demonstrating an animal comfortable in both worlds," said Berger, the principal author of the paper, in an earlier telephone press conference.

Both specimens were about 1.27 metres (4 feet two inches) in height. The female weighed about 33 kilos (72.6 pounds) and the young male 27 kilos.

The species had small brains, measuring about a third of the volume of those of modern humans.

But Berger noted that the shape of their brains appears to have evolved from other species of australopithecus.

"Australopithecus sediba appears to present a mosaic of features demonstrating an animal comfortable in both worlds," said Berger, the principal author of the paper.

The new species had many physical characteristics similar to those of early hominids that would help to explain what it means to be human, he said.

The skeletal structure of the two fossils is similar to those of the first Homo species, but the new examples appear to have employed it in the same way as "Lucy," perhaps the world's most famous fossil.

Found in 1974, Lucy dated back 3.2 million years and was considered the common ancestor of humanity until the discovery of the 4.4-million-year-old "Ardi", which points to a common ancestor with the chimpanzee.

Berger said it was not possible to establish the "precise" position of the new species in relation to early man.

"We can conclude that this new species shares more derived features with early Homo than any other known australopith species, and thus represents a candidate ancestor for the genus," he said.

The site of the discovery is rich in fossils and at least two other specimens of sediba have been excavated and are being analysed, Berger said.

The searchers have also identified the fossils of at least 25 other animal species, including a hyena, a wild dog, antelopes and a horse.

Thai forces use tear gas, water cannon on protesters

Thai security forces used tear gas and water cannon Friday against anti-government protesters who stormed a television station on the outskirts of Bangkok, an AFP reporter witnessed.

The authorities said about 12,000 demonstrators massed outside the broadcaster to try to put an anti-government TV channel back on air, triggering a tense standoff with thousands of security personnel.

Some of the protesters managed to force their way into the compound of Thaicom, which was protected by barbed wire.

The Red Shirt protesters have defied a state of emergency announced by Prime Minister Abhisit Vejjajiva, vowing to keep up their almost month-long mass rallies in the Thai capital.

US-China held constructive yuan talks: report

US Treasury Secretary Timothy Geithner held constructive talks on the yuan in China, prompting optimism that Beijing could soon move to change its exchange rate policy, a report said Friday.

Geithner made a quick visit to Beijing late Thursday for a meeting with Chinese Vice Premier Wang Qishan, the cabinet official in charge of economic and financial issues, that lasted for more than an hour.

The two sides issued nearly identical brief statements after the talks, saying they had discussed economic relations and the global financial situation, but neither country specifically mentioned the Chinese currency.

An unnamed US official however told The Wall Street Journal that the issue had been discussed, qualifying the talks as "constructive".

The official said the US side, while not expecting a specific pledge of action from Beijing given its concerns about being seen as bowing to US pressure, was encouraged that China would soon take action, the report said.

But the official emphasised that no breakthroughs were reached.

The yuan has been effectively pegged at 6.8 to the dollar since mid-2008.

The United States and China's other key trading partners have been piling pressure on Beijing to allow the yuan to appreciate, saying it is undervalued and gives the Asian nation an unfair advantage by making its exports cheaper.

US lawmakers had been pushing the US Treasury to label China a "currency manipulator" -- a move that would open the door to sanctions.

But a week ago, the Treasury announced the delay of a report that had been expected in mid-April and which could have slapped China with the "manipulator" tag, with Geithner saying there were better ways to advance US interests.

Geithner and Wang discussed other issues on Thursday, including the concerns of US companies about Beijing policies they say put them at a disadvantage in the Chinese marketplace, the Wall Street Journal said.