the-BA : Science News Digest

Cheetahs live up to their name (image copyright: istockphoto.com)

In the science news this week: scientists reconsider how the way we walk evolved, DNA catches cheating cheetahs and new breast cancer genes are identified. Plus, the cow that delivers skimmed milk straight from her udders and the race for human ‘hibernation’…

The conventional view of how our human ancestors evolved to walk upright on two legs needs to be revised, according to a new study published in the journal Science.

The tradition theory is that man’s ancestors came down from the trees and went through a stage of knuckle-walking on all fours before evolving into a straight-backed two-legged runner. But 3,000 observations of the movements of wild orangutans among forest treetops, along with fossil evidence, suggests instead that a common ancestor of all great apes evolved upright walking while living among the trees, which helped it forage for food in the small branches of tropical forests.

The researchers think that this ability then helped human ancestors adapt to walking on two feet when they started living on the ground, reported the Times.

Another heated debate has erupted with regards to a fossil that provided support for the theory that birds evolved from dinosaurs, the Daily Telegraph reported. Discovered in 1994, the Sinosauropteryx fossil showed fibre-like structures that its Chinese researchers claimed were primitive feathers. The new row follows the discovery of another Sinosauropteryx fossil specimen that has been studied under a high-powered microscope.

Professor Theagarten Lingham Soliar, who led the research, claims that the structures that were proclaimed as early feathers instead show a striking similarity to dermal collagen – such as that found on the skin of sharks and reptiles today.

’The wider question of whether or not birds originate from dinosaurs does not concern the present study,’ emphasized Professor Lingham Soliar. But questioning the general reliability of original protofeather investigations, he stressed that ‘scientific rigour is called for’, since the evolution of the feather is such an important moment in the history of life.

Cheetahs really do live up to their name, it seems: genetic testing has revealed evidence of extensive infidelity among the big cats.

The discovery, reported in the Times, comes as a result of a nine-year study by the Zoological Society of London and overturns the assumption that among wild cats a single male fathers a litter and only the male is promiscuous. Rather, genetic analysis of cheetah litters in the Serengeti National Park of Tanzania, using DNA extracted from their droppings, showed that 43 per cent of litters contained cubs with different fathers.

Although this strategy of mating with multiple partners places female cheetahs at greater risk of catching sexually transmitted diseases, or even being killed by lions or hyenas as they roam miles searching for another mate, it ensures the genetic diversity of the cubs. It may also reduce the risk of adult males killing the young.

Scientists have uncovered a new weapon which could protect humans against a global bird flu pandemic. An international team of researchers found specific antibodies found in the blood of four avian flu survivors that, when reproduced, proved effective at neutralising infection of the H5N1 virus in mice. Importantly, mice survived well even when treatment was delayed by three days. The findings were published in the journal PLoS Medicine.

Wellcome Trust researcher Dr Cameron Simmons told the Daily Telegraph: ’We are optimistic that these antibodies, if delivered at the right time and at the right amount, could also provide a clinical benefit to humans with H5N1 infections.

’In particular, we found that it was possible to administer the treatment up to 72 hours after infection. This is particularly important as people who have become infected with the virus do not tend to report to their local healthcare facilities until several days after the onset of illness.’

The Guardian announced what it called ‘the most significant advance in the understanding of breast cancer for a decade’: the discovery of four genes that can increase the risk of developing the disease by 60 per cent. The genes were found following a genome-wide search, using techniques similar to those that helped uncover obesity-linked genes in April.

Only up to one in ten breast cancers have a genetic element, and the newly implicated genes only account for four per cent of these – responsible for up to 179 of the 44,000 diagnosed each year. However, scientists are excited by the discovery because three of the genes are involved in cell processes that have never been linked to breast cancer before, opening the door to new research directions.

In the same week that the discovery of these breast cancer genes were announced, the Daily Telegraph reported that binge drinking on alcohol can more than double the risk of developing the disease.

The study, which monitored the lifestyles of 17,647 nurses from 1993 onwards, revealed that women who drink between 16 and 21 units in just two days – the equivalent of two bottles of wine in a weekend – have a 151 per cent higher chance of developing breast cancer than those who don’t drink excessively. Experts believe that increased alcohol consumption is primarily to blame for the increased incidence of breast cancer in the UK.

The Daily Telegraph also reported on the intriguing possibility that our gut bacteria could be playing a role in our struggle with obesity...

The Times revealed that the EU is funding research to enable the reintroduction of animal remains into farm feed for pigs and chickens. The use of animal proteins in animal feed was banned seven years ago following the BSE crisis.

The statutory advisory committee to the EU, the European Economic and Social Committee, says that the studies currently underway clearly show that the use of meat meal from nonruminants (i.e. excluding cows) can be used in pig and poultry feed without posing any danger to human health.

Aberdeen University bacteriologist Hugh Pennington, who is an expert in BSE and its human form, vCJD, commented: ‘There needs to be a rigourous scientific assessment of any plans to reintroduce meat meal to pigs and chickens, which would have to be entirely independent of the EU. We will have to find out about the risks of influenza and salmonella being passed from pig to chicken, or vice versa. The biggest problem will be to win over public opinion.’

A New Zealand biotech company, ViaLactia, has discovered cows that naturally produce skimmed milk and milk low in saturated fats that could be used to make butter that is spreadable straight from the fridge. The cows were found after the company screened the milk compositions of its entire four million strong herd of cattle.

One cow, identified as Marge, produces milk that is not only ‘skimmed’ but also contains omega 3 oils. A spokesman for the company told Chemistry & Industry magazine: ‘The eureka moment was when we found her daughters produced milk just like her mother.’

The company is now likely to develop a commercial herd, although it is unknown how long this will take, reported the Daily Telegraph. The herd could help meet the demands of a growing number of health-conscious consumers without creating an excess of surplus fat that is currently a side product of converting full-fat milk into skimmed and semi-skimmed.

Other news in brief:

The total number of planets known beyond our solar system has increased to 236, after 28 new planets, all gas giants, were detected.
(BBC News)

Crucial talks are being held about the future of Europe’s Mars rover mission, set to be launched in 2013. European Space Agency scientists are asking member states, including the UK, to approve a more expensive, upgraded design which would yield more data and also remove reliance on US spacecraft for communications with Earth.
(BBC News)

In the run up to next month’s G8 summit, the charity Oxfam has said that the UK needs to pay a further 1.2 billion pounds to help poorer countries cope with climate change, on top of the 20 million pounds already pledged.
(BBC News)

Meanwhile, it seems that efforts to orchestrate a global agreement on greenhouse gas emissions at the G8 summit will not have the support of India, despite a year-long diplomatic campaign by Britain to engage the country on the global warming issue.

The nation’s environment minister, Pradipto Ghosh, said India will oppose any attempts to set legal limits on emissions as these would adversely impact the GDP growth of developing countries such as theirs, along with their attempts to alleviate poverty. Although not a member of G8, India, along with Brazil, China, Mexico and South Africa, has been invited to the summit.
(Daily Telegraph)

Following the reintroduction of Golden Eagles to Glenveagh National Park in Ireland six years ago, the country has seen its first hatching of a wild chick for nearly a century.
(BBC News)

Leading fertility expert Robert Winston spoke out at the Guardian Hay festival about his concerns regarding the UK’s IVF industry: that it has become a massive commercial industry in the UK and that that money is corrupting the whole technology. He believes couples are being exploited – paying thousands for tests on the false promise that they will increase their chances of conceiving.

He highlighted the differences between IVF in London and Melbourne; both cities have comparative success rates but treatment in London can cost 10 times more.
(The Guardian)

Scientists have found an association between particular variants of two genes and the type of language spoken: tonal (such as Chinese) or non-tonal (such as English). The finding suggests that the development of particular languages could have been influenced by genetic differences between human populations around the world – although more work is needed to confirm a causal effect.
(The Times)

And finally...

The Times announced that the race is on to become the first to successfully test induced human hibernation, where people are chilled into a state of suspended animation.

NASA abandoned work on induced human hibernation as a way to help astronauts survive long space missions 20 years ago, but money for research in America has started flowing again after a Japanese man survived 24 days in a frozen coma after falling down a snowy mountain and breaking his hip. The European Space Agency has also been funding such research since 2004.

Now,the first human trial is set to begin in the US before the end of the year and aims to increase the survival chances of trauma victims seriously hurt in a car crash. By using a plasma solution to rapidly cool the body temperature of seriously wounded individuals at the scene of injury, their metabolic rate could be slowed, the damage from wounds limited and the onset of shock delayed. Replacing the plasma with warm blood would then revive the patient when safe to do so.

Experiments in pigs by trauma specialist Hasan Alam, a surgeon at Massachusetts general hospital, have already demonstrated the potential of such a treatment. Heart and electrical brain activity were stopped for two hours and the animals successfully revived with no apparent long-term effects.

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