South African fossils: Between ape and human

Two fossil skeletons of early humans appear to mark a halfway stage between primitive "ape-men" and our direct ancestors.

A year of detailed study has revealed that the skeletons are a hodgepodge of anatomical features: some bones look almost human while others are chimpanzee-like.

The two fossils, an adult female and a juvenile male, were discovered in the Malapa cave system near Johannesburg, South Africa, in 2008.

Both about 1.2 metres tall, they are unusually complete and well-preserved and date from 1,977,000 years ago.

Excavated by Lee Berger of the University of the Witwatersrand in Johannesburg, and colleagues, they were given the name Australopithecus sediba.

Australopithecines were early hominids that lived between 4 and 2 million years ago: the best-known fossil example is a 3.2-million-year-old Australopithecus afarensis skeleton found in Ethiopia and nicknamed Lucy. Unlike chimpanzees and other apes, they walked on two legs, but their brains were still small. Not until Homo erectus evolved, around 1.8 million years ago, did larger brains appear.

Together with a large team of researchers, Berger has spent the last year intensively studying the two A. sediba skeletons. He says they are unusually advanced for an Australopithecus, and may show how the australopiths evolved into humans.
Brainy

One area of particular interest is the brain size. So far, the male skull has been excavated. It's also been named: South African schoolchildren chose the name Karabo, which means "answer" in the Setswana and Sotho languages of southern Africa.

Kristian Carlson of the University of the Witwatersrand and colleagues used synchrotron scans to build a detailed 3D image of the inside of the skull, allowing them to calculate the shape of Karabo's brain.

This was small even for an australopith, with a volume of just 420 cubic centimetres. A. afarensis, by contrast, averaged 459 cc, despite being an earlier species. That suggests there was no overall increase in brain size over the course of australopith evolution.

But Carlson says A. sediba's brain had been subtly reorganised. The orbitofrontal region, which sits just behind the eyes, is a different shape to those of other australopiths and apes, and may have been rewired into a more human-like design.

Carlson draws particular attention to an area called the inferior frontal gyrus, which has bulged out in A. sediba. In modern humans this area is important for language processing, hinting that A. sediba had advanced communication skills.

Carlson remains cautious, however, pointing out that spoken language relies on adaptations like vocal cords. Although neck bones were part of the find, they have not yet been studied in detail, so we don't know if A. sediba was built for speech.

We need to treat the brain studies with great caution, says Robert Barton of Durham University in the UK. "Interpretation of surface features of brains is fraught at the best of times," he says, "but on individual specimens that are merely impressions of the original brain and millions of years old to boot?"

Borneo mega-dams proposal raises fears for tribes, wildlife

A massive tract of Borneo jungle, an area the size of Singapore, will soon disappear under the waters of the Bakun dam, a multi-billion-dollar project nearing completion after years of controversy.

The dam, which forced thousands of indigenous people off their ancestral lands, has struggled through setbacks and delays since its approval in 1993, as well as fierce criticism over its environmental impact.

But even before the turbines of the 2.2 billion dollar hydro-electric facility begin to turn, activists have sounded the alarm over plans for 12 more mega-dams on Malaysia's half of Borneo which it shares with Indonesia.

Balan Balang, an elderly chief of the Penan tribe, sighs as he talks of the Murum dam, the first of the dozen dams envisioned for Sarawak state, which will drown the hunting grounds and burial sites of his people.

"This government is very bad. In the old days people would fight us using machetes or spears. But now they just sign away our lives on pieces of paper," said the headman, who sports the elongated earlobes distinctive to his tribe.

"My people never want to leave our place. We want to die in our place," he said, after a long journey from his rainforest home to seek help from indigenous lawyers in Miri, a coastal town in Malaysian Borneo.

Human rights activists are intent on avoiding a repeat of the botched relocation of some 15,000 indigenous people in the Bakun area who they say have made an unhappy transition to life in resettlement areas.

Balan Balang's village is outside the Murum resettlement area, but some 1,500 people -- mostly Penan but including another of Sarawak's tribes, the Kenyah -- will be forced to abandon their homes for an uncertain future.

The chief, who is not sure of his birth date but reckons he is "between 70 and 80 years old", has seen much hardship during his long life.

As a young boy he watched fearfully as Japanese warplanes flew overhead during the World War II occupation, while rampant logging later degraded the jungles where his people forage for food, wild game, and materials for shelter.

"Now the rivers are all polluted. The wildlife has slowly disappeared -- wild boar, deer, gibbons. Even the broad-leafed plants that we use for roofing, and rattan which we use to make mats and baskets, is gone," he said.

But what brought him to Miri are new threats to his way of life, the dam project as well as plantation firms who want to clear what is left of the jungle and grow palm oil and foreign timber species.

"Our people oppose our area being included for the dam because that's where we come from, our ancestors lived and died and were buried there. For us we have no other place, that is our only place," he said.

Your Genome is not that Precious, share it around

Your genome isn't that precious share it around - New Scientist

GENETIC tests are becoming increasingly fashionable, and it's easy to see why: they allow people to find out all kinds of things about themselves, from their family's origin to the likelihood of developing certain diseases and passing on those risks to their children. But there's a flip side: discovering you are susceptible to an illness for which there is no effective cure or treatment can be devastating. There's also the possibility that your genetic data will find its way into the wrong hands and be used against you, allegedly.

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