the-BA : Science News Digest

Brainwaves could help predict mistakes (image copyright: istockphoto.com)

In the science news this week: how the human line almost ‘split in two’, Italian researchers claim to be the first to find dark matter, and the ability to predict mistakes before we make them…

A fascinating DNA study suggests that at one time the human line was on course to evolve into two separate species. A ‘family tree’ compiled of different mitochondrial DNA groupings found on the African continent revealed that, while modern-day Africans are now all one population, a genetic split occurred as long as 150,000 years ago and that distinct populations then lived in isolation for as much as 100,000 years before reuniting.

‘We don't know how long it takes for hominids to fission off into separate species, but clearly they were separated for a very long time,’ said Dr Spencer Wells, Director of the Genographic Project which tracks human migrations via DNA analysis. ‘They came back together again during the Late Stone Age - driven by population expansion.’

Some scientists say it is too early to derive a meaningful picture of our ancestors’ early history in Africa. However, the researchers involved in the study believe the most likely scenario is that two populations separated early on in our evolutionary history and the resulting communities in the south and east remained isolated for an extended period of time, possibly due to climate conditions.

The research, published in the American Journal of Human Genetics and reported by BBC News, also supports the idea that humankind came close to extinction. Numbers may have dropped as low as 2,000 before rising in the Late Stone Age.
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For the first time, sophisticated molecular sequencing of proteins obtained from fossils has confirmed that dinosaurs such as T. rex are closely related to modern birds, while elephants are indeed the closest living relatives of the mastodon, reported the Guardian.

While the conclusions aren’t that surprising, fitting with existing evidence, the key advance, according to researcher Dr Chris Organ from Harvard University, is the proof that it possible to understand detailed relationships between extinct and living species using intact proteins from fossils.
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An archaeologist from University College London believes that images pressed into Mesopotamian bottles stops some 5000 years ago were the first examples of logos, so common in brand identification these days.

Think of any particular product – cola, trainers, washing powder… – and companies that have been particularly effective at developing their brand jump to mind. Dr David Wengrow claims that the practice of product branding first emerged in what is now Iraq, when the start of urbanisation brought increasing numbers of strangers with products of uncertain origin, and mass production of alcoholic drinks, textiles and dairy products began.

Personalised stone seals had been used to make impressions on food and drink caps and stoppers by villagers as long as 8000 years ago. But they later came to play an important role in communicating the quality and origins of products such as oils and wine – developing into recognisable logos that could reassure the buyer.
(newscientist.com)
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New research suggests that a woman’s diet around the time of conception may influence her baby’s gender. Researchers from the Universities of Exeter and Oxford asked 740 first-time pregnant mothers in the UK to provide records of their eating habits before and during early pregnancy. The data indicates that high-calorie diets and regular breakfasts might increase the chances of having a boy – 56 per cent of women with the highest energy intake around the time of conception gave birth to boys, compared to 45 per cent of those with the lowest energy intake. Women who had girls consumed an average of 2,283 calories a day, compared to an average of 2,413 among women with sons.

The study also found that those with a son were more likely to have eaten breakfast, and consumed more nutrients such as potassium, calcium and vitamins C, E and B12, reported BBC News.
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Scientists have been searching for elusive ‘dark matter’ since it was first postulated in the 1930s to account for the huge gravitational pull apparently holding distant galaxies together. Now, reports the Guardian, researchers at the University of Rome claim to have detected signs of it using a giant detector underneath an Italian mountain. They made the announcement at a physics conference in Venice. US astrophysist Frank Halzen, who heard the talk, said afterwards: ‘We are pretty sure now that this is not a statistical fluke. We should pay attention to this.’

Underground laboratories are used for experiments to detect dark matter so that they are shielded from other particles that could mask the relevant signals. British researchers joined the hunt for dark matter earlier this year, using a laboratory inside an old Yorkshire salt mine.
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Stunning images of galaxies colliding, captured by the Hubble Space Telescope, were released by NASA this week to celebrate the 18th anniversary of the telescope’s launch. They show various aspects of the interstellar collision process. Read more and view the images in the Independent.
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Scientists investigating the potential impacts of ambitious geoengineering plans put forward to tackle climate change by reducing the amount of sunlight reaching the planet’s surface warn that ‘trying to artificially cool off the planet could have perilous side effects’.

Dr Simone Tilmes of the National Centre for Atmospheric Research in Boulder, Colorado, co-author of the study published in Science, says: ‘While climate change is a major threat, more research is required before society attempts global geoengineering solutions.’

Various strategies have been proposed to help cut surface temperatures. One such technique is the injection of sulphate particles into the atmosphere, to mimic the effects caused by major volcanic eruptions. Dr Tilmes and Dr Rolf Müller of the Jülich Research Centre, Germany, looked at what impact this could have on the protective ozone layer above the Earth’s poles. They concluded that the approach could destroy between about one- and three-quarters of the ozone layer above the Arctic over the next few decades because, while the sulphates themselves don’t cause direct destruction of ozone, they provide a surface on which chlorine gases in the cold polar lower stratosphere can become activated, leading to damaging chemical reactions.
(The Telegraph)
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And finally…

Researchers have found that our brains have a tendency to switch to autopilot when performing monotonous tasks and that it’s possible to predict upcoming mistakes up to 30 seconds before they’re made, based on brain activity patterns.

In the study, participants were asked to respond quickly to visual cues, while their brains were scanned using functional magnetic resonance imaging. The researchers observed that mistakes were preceded by reduced prefrontal cortex activity and increased activity in an area more active in states of rest, reported BBC News.

The discovery leads to the intriguing possibility that, if more portable EEG devices are able to detect the changes, an early-warning system could be designed to measure brain signals and alert individuals to refocus and be more careful. This could improve performance in tasks where focus can be hard to maintain, such as driving, passport control and x-ray analysis.

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