Man evolved to throw punches
Did the human hand evolve so that early man could punch his love rivals in the face? The received wisdom is that shorter palms and fingers, and longer, stronger thumbs, made early man better able to
manipulate tools, and that it was this that drove their evolution. But scientists at the University of Utah have run a gruesome study to back the theory that these proportions also confer another
advantage – the ability to throw a powerful punch. For the study, the researchers took arms from nine
cadavers, and attached fishing wire to the tendons in the hands. Tightening or slackening these wires enabled them to create either an open hand for slapping, or a closed fist for punching. Then, using
a pendulum, they swung the dead arms towards a force-measuring pad. Their results showed that a punch with a clenched fist has twice the force of a slap with an open hand, and also that the strain on the metacarpal bones is greatly reduced when the fist is clenched. “An individual who could strike with a clenched fist was better able to fight for mates, and thus more likely to reproduce,” said Professor David Carrier, the study’s author.
A dry January does work
Countless people gearing up for the Christmas party season will be pencilling in a dry, or teetotal, January, in the hopes it will undo some of the damage wrought by festive drinking. And it could work, says The Daily Telegraph: a study at University College, London, found that abstaining from
the party life style for four weeks heals the liver, and improves blood pressure and cholesterol levels. The researchers tracked 102 people who had all drunk heavily in December, then went teetotal for January. After the four-week break, their liver “stiffness” – an indication of damage – was reduced by 12.5%, on average; while resistance to insulin – a marker for diabetes risk – was down by 28%. The participants also typically lost 3kg in weight. Their blood pressure and cholesterol levels dropped, and many said they were finding it easier to sleep and to concentrate. The study is a larger version of one involving 10 journalists at New Scientist magazine, which got similar results earlier this year.
However, neither study established how long the effects last if (or when) abstainers return to their former drinking levels.
Life on early Earth
In the first 700m years after the Earth’s formation, scientists have long believed, our planet was a hellish realm devoid of life – with asteroids raining down on a landscape riddled with volcanoes, molten rock, and poisonous gases. But new research suggests that life may have taken root in the Earth’s turbulent youth – 300 million years earlier than previously suspected, reports HuffingtonPost .com. Our planet formed roughly 4.5bn years ago, and was heavily volcanic for eons as it slowly cooled. The earliest fossil records date to about 3.8bn years ago, when single-celled creatures began to appear. But by studying tiny crystals that form in magma, called zircons, geochemists at the University of California at Los Angeles found microscopic flecks of pure carbon with a signature indicating it had been left behind by living organisms 4.1bn years ago. “Life on Earth may have started almost instantaneously,” says study co-author Mark Harrison. “With the right ingredients, life seems to form very quickly.” He said the study suggests that simple life-forms may be quite common
throughout the universe.
The plastic in your fish
Scientists have long suspected that waste dumped into the ocean would ultimately find its way into the seafood that ends up on dinner tables. A new study provides evidence that this is more than just a
theory, reports PopularScience.com. After analysing fish caught off the coasts of California and Indonesia and sold in local markets, researchers found 25% contained man-made debris. All of the fragments found in Indonesian fish were plastic, while textile fibres accounted for 80% of the debris found in fish from California. The study’s authors say this difference reflects the waste management strategies in each region. Indonesia often dumps garbage directly onto beaches and into rivers. The United States has more advanced waste-processing systems, including plastic recycling, but effluent
from washing machines sent to wastewater treatment plants is laden with synthetic fibres. In each case, the waste is becoming part of marine habitats. “This is a wakeup call,” says the study’s author, Chelsea Rochman, warning that waste dumped into oceans “might be coming back to haunt us through the food chain.” So far, researchers have found plastic and fibre in the fishes’ guts, not their flesh. But they noted that further research is needed.
Is Earth two planets in one?
Around four and a half billion years ago, a small planet, named Theia, collided with a bigger one, the early Earth, blasting debris into orbit that became the moon – so thetheory goes. But while conventional wisdom has it that Theia merely sideswiped Earth and then carried on into space, scattering debris in its wake, new research suggests it actually smashed headon into Earth, fusing
the two planets together. Researchers from the University of California analysed the moon rocks brought back by the Apollo missions, and volcanic rock from Earth’s mantle, to compare their oxygen isotopes. As rocks on each planetary body in the Solar System have a unique oxygen isotope ratio, they expected to find significant differences between those from Earth and those from the Moon, which would be expected to be made up largely of Theia. In fact, the isotopes turned out to be indistinguishable – suggesting that Theia and Earth became one, and the moon was made from both.
Eat fruit to keep the weight off
Eating more fruit could help people stave off middleaged spread, a new study has found. The researchers looked at data on more than 124,000 people who had been tracked over 24 years, and found that typically, they put on a kilo or two every four years in middle age. However, those who had eaten diets rich in flavonoids – found in grapes, strawberries, blueberries, apples, pears and
oranges, as well as peppers and onions – had tended not to gain any weight, despite consuming similar amounts of calories, while some had lost weight. “People tend to put on weight as they get older,” Aedin Cassidy, from the University of East Anglia, told The Times. “But we found that people
who ate a few portions of flavonoidrich fruits and vegetables a week maintained a healthy weight and even lost a little.” Professor Cassidy conceded that she could not prove that it was the flavonoids that had kept people trim, but said that her team had tried to account for their general diet, as well
as their exercise levels.
A simple test for Alzheimer’s
A simple test of spatial awareness could be used to predict the onset of Alzheimer’s disease up to two years before symptoms appear, reports the Daily Mail. The Four Mountains test involves asking patients with mild cognitive impairment to look at a picture of a mountain. They are then shown
three similar landscapes, one of which is the same one as in the original picture, but taken from a slightly different angle: the challenge is to identify that picture. According to researchers at Cambridge University, trial results suggest the test, developed a decade ago, can predict Alzheimer’s with 85% accuracy in people aged 60 to 79, making it nearly twice as accurate as current memory
tests, and as accurate as expensive brain scans and lumbar punctures.
Why women yawn more than men
It is well established that yawning is contagious. Now researchers have found that it’s more “catching” among women – reinforcing the theory that contagious yawning is rooted in empathy. The team, from Italy’s Pisa University, observed more than 100 people – at work, in social situations, and elsewhere – over the course of five years, and noted how often they yawned, reports The Independent. They found both men and women yawned spontaneously at about the same rate; and that both sexes were more likely to “catch” a yawn from someone they were close to, or familiar with, than from a stranger. However, women were significantly more prone to contagious yawning than men. The researchers suggest this is because women have evolved to be more empathetic on account of their maternal role. However, previous studies have failed to find a gender link, and other
experts said further evidence was needed.
Why aliens aren’t saying hello
For decades, astronomers have searched in vain for signals from extraterrestrial life, and now planetary scientists in Australia suggest there’s a good reason why aliens are so hard to find: They didn’t last long enough to develop intelligence. Most theoretically inhabitable planets have unstable
environments, the researchers say; like Mars and Venus, planets can have an early temperate period but then be transformed into frozen wastelands with thin atmospheres or blistering worlds with boiling oceans. The microbial life that arises on these worlds almost always becomes extinct. “The universe is probably filled with habitable planets, so many scientists think it should be teeming
with aliens,” author Aditya Chopra, an astrobiologist at Australian National University, told CBSNews.com. “But early life is fragile, so we believe it rarely evolves quickly enough to survive.” Since intelligent life appears to require billions of years of evolution on a planet with an unusually stable environment, he theorises, it may be extremely rare – and perhaps even unique to Earth.