the-BA : Science News Digest

Walking vs taking the bus (Image copyright: istockphoto.com)

In the science news this week: a significant step towards creating artificial life, the benefits of relaxing your brain and why it’s a mistake not to wait for the bus...

The discovery by Chinese archaeologists of a fossilised skull that includes a rare membrane is being hailed their biggest find in almost 80 years, reported the Guardian. Thought to date back 80,000 to 100,000 years, the skull may reveal important details about ancient man’s nervous system and could help shed light on the contentious issue of whether most of China’s 1.3 billion population are mainly indigenous, descended from people who originated in Africa, or are intermixed.

Scientists outside of China shared the excitement. Dennis Etler, a palaeoanthropologist at Cabrillo College, California commented: ‘This is a crucial period in human evolutionary history, but we know almost nothing about it. Anything coming from that period is of great interest to the outside world. This sounds like a breakthrough.’

The Xuchang Man skull, named after the city in where it was found in the central Henan province, consists of 16 fragments and shows protruding eyebrows and a small forehead.
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Other Chinese skeleton fossil samples have revealed that people have been wearing shoes for at least 40,000 years. Shoes alter the way a person walks and so differences can be observed between the toe bones of shoe-wearers and non-shoe-wearers. The latest study compared the toe bones of modern Americans’ feet and late-prehistoric Native Americans and Inuits, with those from a 40,000-year-old skeleton discovered in a Tianyuan cave near Beijing.

Mr Trinkaus, one of the researchers, said: ‘Modern shoe-wearing Americans have wimpy little toes. Barefoot native Americans have strong, large toes. Shoe wearing Inuits lie somewhere in between.’

Since the Tianyuan toe bones were found to be most similar to the Inuits’, it suggests they regularly wore shoes, the Telegraph reported.
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American scientists have taken the next step towards creating a fully-replicating, man-made organism. Led by Craig Venter, well-known for his work sequencing the human genome, researchers completely chemically synthesized the entire genome of a free-living micro-organism.

The successful manufacture of the 582,970 nucleotide sequence of Mycoplasma genitalium takes the group one step closer to their ultimate aim of making artificial life forms that can help solve some of the world’s urgent environmental problems. For instance, the scientists hope one day to be able to use such organisms to produce green biofuels, break down toxic waste and absorb carbon dioxide from the atmosphere.

Dr Venter emphasized that safety precautions would ensure any new microbes created would be incapable of infecting other organisms. Self-destruct mechanisms would also be built into their DNA so that they would be incapable of surviving outside of the laboratory.
(Read more in the Independent)
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In a letter to the Times this week, a group of leading scientists called on the Government to accept amendments to the Human Fertilisation and Embryology Bill that is currently passing through Parliament, saying that new consent laws planned will seriously delay life-saving medical research. The 29 biomedical research and administration signatories included Nobel medicine laureates Sir Martin Evans, Sir Paul Nurse and Sir John Sulston, as well as stem-cell experts such as Sir Ian Wilmut, Dame Julia Polak, Professor Stephen Minger and Professor Robin Lovell-Badge.

They warn that new consent laws requiring all tissue used to create cloned embryonic stem cells to have the explicit consent of its donor will deny stem-cell scientists the use of valuable tissue banks for studying diseases such as muscular dystrophy, Parkinson’s and diabetes. While they agree that it is proper to obtain explicit consent from patients donating tissue or eggs in the future, they argue that the rules shouldn’t be applied retrospectively to samples donated with general consent for unspecified medical research.

Another provision in the Bill seeks to block the use of any tissue from children, even if their parents give consent. This already has implications for some of Professor Minger’s research. An American colleague has offered the use of cells collected from children with spinal muscular atrophy, a rare genetic wasting condition.

‘We want to use these to produce stem cells to study SMA, and we cannot get this genetic material any other way,’ said Professor Minger. ‘Children with the worst form of this condition do not live to adulthood. It is impossible to wait until they are old enough to give their own consent.’

Amendments to both measures, tabled by the chairman of the UK Stem Cell Network Steering Committee, Lord Patel of Dunkeld, were being debated in the House of Lords.

However, the Government and some campaigners argue that some patients may not have donated their cells for research had they known the work could involve embryos.

Dr Calum MacKellar, of the Scottish Council on Human Bioethics told the Telegraph: ‘For scientists to clone human embryos without the consent of cell donors, which contains the genetic material, would be completely unethical. It would be like creating an identical twin embryo of a person by using his or her cells without consent. A certain amount of humility is required from the scientists who have signed this letter. They need to realise that it is not because the research is acceptable to them that is it not extremely offensive to many patients and a large section of the UK general public.’
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An international consortium announced the ‘1000 Genomes Project’ that will sequence the genomes of at least 1000 people around the world, creating the most detailed picture to date of human genetic variation. Not only will the project accelerate the search for genetic variants implicated in the susceptibility to common diseases, but also potentially provide valuable new information significant to both medicine and basic human biology. Genetic information will be collected from numerous different populations.

Dr Gil McVean, one of the co-chairs of the consortium’s analysis group told the Telegraph: ’This project will examine the human genome in a detail that has never been attempted – the scale is immense. At six trillion DNA bases, the 1000 Genomes Project will generate 60-fold more sequence data over its three-year course than have been deposited into public DNA databases over the past 25 years.’
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Dr Rob Jenkins, who gave one of the Award Lectures at last year’s BA Festival of Science, has published work in the journal Science showing that a ‘face averaging’ technique can dramatically improve the success rate of computer face-recognition systems.

His work is based on the principle that people are able to recognise familiar faces much better than ones they’ve not seen before. By making a composite image that averages 10 images of the same person’s face, his software removes variations caused by things such as different lighting or camera angles. ‘These things affect the image a great deal but they don’t tell you anything about who it is,’ he said. ‘It is like you are extracting the essence of that person’s face.’

He tested his technique using the face recognition software FaceVACS. The system is being tested at Sydney airport, but is already used on the website MyHeritage.com in a celebrity lookalike service which matches images of users to the most alike celebrity featured within their database of more than 31,000 photographs.

Dr Jenkins and colleagues submitted 459 celebrity images to the system, all of who were within the database. The FaceVACS system matched them correctly 54 per cent of the time. However, when they resubmitted averaged images that they had created, the accuracy increased to 100 per cent.

’One thing I really like about this approach is we are proposing a technique, not a device,’ he told the Guardian. ‘We are saying, you can keep the same machines, but if you can change the input you can radically improve their performance.’
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Origami masters have used their talents to help design a new kind of spacecraft – an eight inch paper airplane that will be launched from the International Space Station.

Professor Shinji Suzuki, from the University of Tokyo’s Department of Aeronautics and Astronautics, who worked on the project with the Japan Origami Airplane Association, hopes that the project could inspire new designs of lightweight re-entry vehicles or upper atmosphere exploratory planes.

A successful test last week suggests the plane, which is made of folded silicon treated heat resistant paper and has a rounded nose, could survive the descent to Earth, reports the Telegraph. It is expected to travel at Mach 20 (20-times the speed of sound) when released, but slow to Mach 7 within the Earth’s atmosphere.

’We hope the space station crew will write a message of peace on the plane before they launch it,’ Professor Suzuki said. ‘We don’t know where in the world the plane will land, but it would be nice to send a message to whoever finds it.’ He also plans to include a message, written in many different languages, asking the person who finds it to return it to the Japan Origami Airplane Association.
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We’re more likely to have a ‘Eureka!’ moment (where the solution to a vexing problem falls into place suddenly) when our brain is relaxed and open to ‘free-floating ideas’. This is according to scientists who studied the brain rhythms of volunteers tackling verbal problems.

They monitored 21 volunteers who needed to generate a solution word that would form a valid compound word or phrase with each of three test words. For example, ‘lamp’ is the solution to ‘head, shade, post’.

The scientists were able to predict whether the subject would succeed or fail according to their brain rhythm. They found that excessive gamma brain rhythm (indicative of focussed attention) was often associated with a mental block. A higher alpha brain rhythm (linked with a relaxed brain with free-floating ideas) in the right side of the brain would lead to the correct solution.
(Read more in the Telegraph)
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And finally...

The Times announced good news for the lazy among us: it almost always makes mathematical sense to wait for the next bus for a short journey rather than walk to your destination.

Only when a bus isn’t due for an hour or more and your destination is less than a kilometre away is it worth walking, according to a group of American mathematicians who decided to take a logical approach to the common conundrum faced by those whose journey coincides with a bus route.

Their paper, ‘Walk versus wait: the lazy mathematician wins’, explains their formula, which incorporates journey variables such as distance, number of bus stops, walking speed and bus speed.

’Many mathematicians probably ponder this on their way to work, but never get round to working it out,’ said Scott Kominers, of Harvard University. ‘It certainly has changed the way I travel.’