the-BA : Science News Digest

Elephant (Image copyright: istockphoto.com)

In the science news this week: our African ancestors who enjoyed a shellfish meal 164,000 years ago, the discovery by amateur stargazers that our universe could be ‘lopsided’, and ‘space diving’, the latest extreme sport...

The Telegraph reported a discovery that has pushed back the origins of the evolution of modern human behaviour.

The remains of shellfish found in a cave at Pinnacle Point on the Cape of South Africa are thought to be the earliest evidence to date of humans using marine resources and coastal habitats. Researchers discovered the material buried in 164,000-year-old sediments.

Along with findings suggesting that humans were eating mussels, clams and sea snails, scientists discovered pigments, in particular red ochre, that the team believed were used symbolically – suggesting that modern language may have been used. They also found tools – tiny blades less than 10 millimetres wide – that significantly predate the earliest blade technology found so far.

‘Archaeologists have had a hard time finding material residues of these earliest modern humans,’ explained Professor Curtis Marean, who led the work published in Nature. ‘The world was in a glacial stage 125,000 to 195,000 years ago, and much of Africa was dry to mostly desert; in many areas food would have been difficult to acquire.

‘For millions of years, our earliest hunter-gatherer relatives only ate terrestrial plants and animals. Shellfish was one of the last additions to the human diet before domesticated plants and animals were introduced.’

It is thought small bands of hunter-gatherers were driven to towards the sea when Africa was mostly desert. Studies of ancient climates suggested to Professor Marean that there were only five or six places in the whole of Africa where humans could have survived. He narrowed down which site to explore on the basis of data such as ocean currents, climate and geology.
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Elephants have demonstrated an impressive ability to distinguish between different human tribes based on the smell and colour of their clothing, reported the Independent.

Whereas members of the Kamba tribe pose little threat to elephants, young male members of the Maasai tribe are known to sometimes spear elephants to prove their virility. Anecdotal evidence had suggested the elephants might be able to tell the tribes apart, so scientists from the University of St Andrews and the Amboseli Trust for Elephants in Nairobi decided to devise an experiment to test this.

Herds of elephants in the Amboseli National Park in Kenya were exposed to garments of the two tribes, some worn, some not. The researchers observed that the animals reacted more aggressively to the red colour of the traditional Maasai clothing than to white clothing. They were most relaxed in the presence of unworn clothes, and became significantly more nervous in the presence of Maasai clothing compared to Kamba garments, moving away more quickly. The reaction was observed even when the clothing was out of sight, indicating the reaction was based on smell.

‘We think this is the first time that it has been experimentally shown that any animal can categorise a single species of potential predator into subclasses based on such subtle cues,’ said study author Professor Richard Byrne.
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Amateur stargazers helping professional astronomers to classify galaxies in the universe at a phenomenal speed have uncovered an apparent lopsidedness to the universe.

The Galaxy Zoo project, run from Oxford University’s physics department, asked the public to sort galaxies into two types: spirals (circular pinwheels like the Milky Way) and elliptical (rugby ball shaped). More than 100,000 people worldwide have logged on to the website to study 30 million images taken by a robot telescope in New Mexico for the Sloan Digital Sky Survey. Their contribution has meant that a preliminary analysis has taken months instead of years to complete.

Dr Chris Lintott, part of the Oxford team, explained that the human eye is much better than computers at classifying the galaxies because of their complex shape. To ensure accuracy, each image was shown to multiple web visitors, and the scientists were struck by how well the amateurs classified them.

Traditionally, galaxies have been expected by astronomers to spin either clockwise or anticlockwise in equal proportion. Remarkably, reports the Telegraph, these preliminary findings suggest that, from the viewpoint of Earth, spiral galaxies are predominantly rotating anticlockwise. If the analysis holds true, ‘you will have to throw away the standard model of cosmology,’ says Dr Lintott.
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James Watson, who won a Nobel prize for his contribution to the discovery of the structure of DNA in 1953, provoked outrage this week when he claimed in an interview with the Sunday Times that black people are less intelligent than white people. He was widely criticised by the scientific community, who said he was out of his depth scientifically and that there was currently no way to accurately test intelligence.

Dr Watson arrived in Britain on Thursday to promote his latest book with a speaking tour. However, various engagements have since been cancelled. The Science Museum, where he was due to speak on Friday, said his comments had ‘gone beyond the point of acceptable debate’. On Tuesday, the Science Museum’s Dana Centre had held a discussion on the history of scientific racism.

BBC News revealed that he has now been suspended from the Cold Spring Harbor Laboratory in New York, where he is Director, ‘pending further deliberation by the board [of trustees]’.

Speaking at a book launch at the Royal Society on Thursday evening, Dr Watson, apologised unreservedly. ‘I cannot understand how I could have said what I am quoted as having said. I can certainly understand why people reading those words have reacted in the ways they have,’ he said. He added that there is no scientific basis for a belief that Africa, as a continent, is somehow genetically inferior, and that is not what he meant. According to the Times, the interview with Dr Watson had been recorded and the Sunday Times stood by their story.
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A number of news stories came out of the annual meeeting of the American Society for Reproductive Medicine, taking place in Washington this week. Research was presented suggesting that men whose fertility problems stem from genetic damage to their sperm would benefit from regular ejaculation. Another study provided the first strong evidence that chlamydia reduces male fertility as well as that of women. Read more in the Times and the Guardian.
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The Guardian also reported that scientists are working on a ‘genetic contraceptive’ that, if it works, would be the first serious advance in chemical contraception since the developments nearly 60 years ago that led to the pill.

The work focuses on the gene ZP3. During ovulation, the gene produces a protein that coats the outside of the egg, a coating which is essential for sperm to be able to attach to the egg. Researchers from Harvard Medical School found that animals bred with the ZP3 gene knocked out were healthy but completely infertile. Using a technique called RNA interference – which uses fragments of genetic material to target specific genes and block their activity – they were able to temporarily block 95 per cent of ZP3 activity in human cells.

Dr Zev Williams, part of the team conducting the research, said: ‘If you could block this in women you could prevent pregnancy from occurring. For women who use the pill just as a contraceptive, a non-hormonal approach would be wonderful. You could get all the benefits without the nausea, the headaches, the mood alterations, and the raised risk of thrombosis, stroke and heart attacks.’
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Chemicals found in the sweat of nursing mothers can increase the sex drive of other women, other research presented at the conference found.

A group of women were asked to complete a daily questionnaire about their mood and sexual desire and asked twice daily to sniff a pad that had been scented with sweat from a breast-feeding mother. Those with partners experienced a 24 per cent increase in sexual desire, reported the Times, while those without partners reported a 17 per cent increase in sexual fantasies. This compared to a control group in which women without partners reported a 28 per cent decrease in sexual fantasies.

The findings, published in the journal Hormones and Behaviour, raise the possibility that an aphrodisiac drug could be developed using these chemical cues to increase women’s libido.
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A site in Argentina known to be a rich source for palaeontologists has yielded one of the largest skeletons ever found, reported the Telegraph. The skeleton, over 105 feet long, could prove to be a new species.

The long-necked plant-eater roamed what is now northern Patagonia about 80 million years ago and has been named Futalgnkosaurus dukei. It measured between 105 and 112 feet from head to tail and was over 43 feet tall. The first bones were found in 2000 and the spinal column alone weighed about nine tons.

The two other largest dinosaurs yet found – Argentinosaurus (approximately 115 feet long) and Puertasaurus reuli (115 to 131 feet long) – were also discovered in Patagonia.
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BBC News announced the discovery of 315 million-year-old fossilised footprints that provide the earliest evidence for the existence of reptiles. The tracks, discovered in sea cliffs at New Brunswick, Canada, suggest reptiles evolved between one and three million years earlier than previously thought.

The evolution of reptiles, in particular of a their shell-protected eggs, meant that four-legged animals no longer had to return to water to lay eggs.

This latest fortuitous discovery was made by Dr Howard Falcon-Lang from the University of Bristol. He says that without shadows caused by a low Sun he probably would have missed the footprints on a slab of rock revealed by a recent rock fall.

’The prints showed that the hands had five fingers and scales, sure evidence they were made by reptiles and not amphibians,’ said Professor Mike Benton, co-author of the study published in the Journal of the Geological Society of London.

The most likely species to have made the prints is thought to be Hylonomus lyelli, a lizard-like reptile. Skeletal fossils of the creature found in 1859 were, until now, the oldest evidence for reptiles. The new material was found in the same general area of rock formation as that discovery but, since the tracks occurred almost a kilometre below, Dr Falcon-Lang says we ‘can be confident the footprints are older than the skeletons’.
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And finally…

Adrenaline junkies could soon enjoy a new thrill-seeking opportunity – skydiving from the edge of space. Entrepreneurs and extreme sports enthusiasts are preparing jumps from an altitude of 22 miles, to break a 1960 record set when Captain Joe Kittinger of the US Air Force jumped from 20 miles. Back then, a speed of around 700 miles per hour was reached during a 13 minute descent. The new challengers intend to build up to a 57 mile altitude to conduct the first true space jump and, if all goes to plan, paying customers could potentially try the daredevil stunt for themselves as soon as 2009.

More seriously, space diving will require the development of special equipment and strategies that could protect future space travellers should they find themselves in emergency situations. These include space suits that can cope with frigid temperatures and near vacuum conditions and contain a circulating liquid cooling system to cope with air friction heating the suit as the jumper plummets towards Earth, as well as a jumping posture that will help avoid an uncontrolled spin that could result in unconsciousness.

Rick Tumlinson co-created the company Space Diver with a team that includes Jonathan Clark, whose wife Laurel was killed in 2003 when the Columbia shuttle disintegrated during re-entry. Ultimately, reports the Telegraph, Tumlinson aims to ‘develop technology that will allow astronauts to eject from orbiting craft and return safely to Earth, for instance in small inflatable “lifeboats”’.

The company plans to begin low-altitude tests with dummies and then people early next year, to test that a diver can eject from a vehicle safely, using a computer controlled craft that will return to Earth automatically following the jump.

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