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Nature, nurture... or neither? New tool lowers dinosaur weight estimates Arctic ice melt prelude to severe winters Prof Yash
Pal
THIS UNIVERSE
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Nature, nurture... or neither? IT is a shibboleth of family life — that every individual is the product of their genes and environment, the one an immutable inheritance, the other a mutable array of influences and pressures with unpredictable outcomes. But new research has demonstrated that genes can change, identical twins with the same genetic inheritance can turn out completely different and the impact of environmental influences can be passed down the generations. The new science of epigenetics has shown that in addition to nature and nurture, what makes us who we are is also determined by biological mechanisms that can switch genes on or off. These epigenetic (above the gene) “light switches” can affect characteristics as fundamental as autism and sexual orientation. But they are also subject to environmental influences and thus, in theory, are within our control. Professor Tim Spector, head of the department of twin research at Kings College, London, who has undertaken the most detailed twin studies in the world, cited the case of Iranian twins Ladan and Laleh, who were joined at the head and shared identical genes and environment and yet had different personalities. The differences led him to question the influence of genes. “Up to a few years ago I believed genes were the key to the universe. But over the last three years, I have changed my mind,” he said at the launch of his book Identically Different: Why You Can Change Your Genes, which challenges the view that an individual’s genetic inheritance is immutable. Studies of the effects of famines in Holland in the 1940s, in China in the 1950s and in the United States over a century ago show they changed the lifespan and obesity rates in subsequent generations. They switched on genes that increased the accumulation of body fat in times of plenty, in order to improve survival chances in times of famine. In the modern world, with calorie-dense fast foods more freely available than at any time in history, the seeds of the current obesity epidemic may thus have been sown in the 19th century. “The risk of obesity can come not just from your own environment or your mother’s but higher up (the ancestral chain),” he said. Four drugs with epigenetic effects that can switch genes on or off are already on the market and 40 more are in development, he said. But there are other, natural, ways of controlling them, too. Exercise has been shown to switch off the FTO gene, a key driver of obesity. Diet can also affect gene expression. “We and our genes are more flexible than we thought,” he said. —
The Independent
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New tool lowers dinosaur weight estimates They discovered that the animals had almost exactly 21 per cent more body mass than the minimum skeletal “skin and bone” wrap volume, and applied this to a giant Brachiosaur skeleton in Berlin’s Museum fur Naturkunde, the journal Biology Letters reported. Previous estimates of this Brachiosaur’s weight have varied, with estimates as high as 80 tonnes, but the Manchester team’s calculations reduced that figure to just 23 tonnes. The team says the new technique will apply to all dinosaur weight measurements, according to a university statement. Bill Sellers from Manchester said: “One of the most important things palaeobiologists need to know about fossilised animals is how much they weighed. This is surprisingly difficult, so we have been testing a new approach. “We laser scanned various large mammal skeletons, including polar bear, giraffe and elephant, and calculated the minimum wrapping volume of the main skeletal sections. “We showed that the actual volume is reliably 21 per cent more than this value, so we then laser scanned the Berlin Brachiosaur, Giraffatitan brancai, calculating the skin and bone wrapping volume and added 21 per cent. “We found that the giant herbivore weighed 23 tonnes, supporting the view that these animals were much lighter than traditionally thought,” said Sellers. Sellers, based in Manchester’s Faculty of Life Sciences, explained that body mass was a critical parameter used to constrain biomechanical and physiological traits of organisms. —IANS
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Arctic ice melt prelude to severe winters THE dramatic melt-off of Arctic sea ice due to climate change could lead to severe winter outbreaks, reveals a study.
Charles H. Greene, Professor of Earth and Atmospheric Sciences at Cornell University, Ithaca, New York (USA), and colleague Bruce C. Monger, senior research associate, detail this phenomenon, the journal Oceanography reported. “Everyone thinks of Arctic climate change as this remote phenomenon that has little effect on our everyday lives,” Greene said. “But what goes on in the Arctic remotely forces our weather patterns here.” A warmer Earth increases the melting of sea ice during summer, exposing darker ocean water to incoming sunlight. This causes increased absorption of solar radiation and excess summertime heating of the ocean — further accelerating the ice melt, according to a university statement. The excess heat is released to the atmosphere, especially during the autumn, decreasing the temperature and atmospheric pressure gradients between the Arctic and middle latitudes. “What’s happening now is that we are changing the climate system, especially in the Arctic,” Greene said. “It’s something to think about given our recent history.” This past winter, an extended cold snap descended on central and Eastern Europe in mid-January, with temperatures approaching minus 22 degrees Fahrenheit and snowdrifts reaching rooftops. There were also the record snowstorms fresh in the memories of residents from several eastern US cities, as well as many other parts of the Eastern Seaboard during the previous two years. —
IANS
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THIS UNIVERSE Jet planes fly at an altitude, where outside temperature is of the order of Why don’t planets prefer a circular path? You have a question on the shape of planetary orbits. You have to realise that the shape is not decided by a supreme being on the basis of a whim. It is the result of what happens when a randomly moving planet goes through a gravitational field of the kind generated by the sun-planet interaction. I agree that the idea of beauty does enter, but ellipses are quite beautiful. You know, of course, that a circle is an ellipse in which the major and minor axes are equal.
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Trends AUSTIN, Texas: When Texas geologist Earle McBride visited Omaha Beach in Normandy, France, in 1988, four decades after D-Day, the visible remnants of the Allied Forces' invasion there had long ago vanished. But he and a colleague would later discover the history of the June 6, 1944, invasion of Normandy’s beaches — which marked a turning point in World War II — lingered in the sand in the form of tiny pieces of shrapnel only visible under a microscope. Gene secrets of opium poppy unlocked LONDON: Scientists have unravelled exactly how opium poppies produce a non-addictive compound that can both suppress coughs and kill tumour cells, paving the way for improved production of the medicine. Opium poppies, the source of illicit heroin, are also important for producing medical painkillers such as morphine and codeine, along with noscapine, which has been used for decades as a cough suppressant. —
Reuters
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A combination of genes and our environment makes us what we are. Or so we always thought...
Scientists have developed a tool to measure the weight and size of dinosaurs precisely and discovered they are not as heavy as previously thought.
Biologists used lasers to measure the minimum amount of skin required to wrap around the skeletons of modern-day mammals, including reindeer, polar bears, giraffes and elephants.