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How humans became most successful species Mystery behind wrinkles revealed TRENDS
Plants are good at maths, say scientists New Atlantis exhibit gives close-up of space flight Prof Yash
Pal THIS UNIVERSE |
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How humans became most successful species
THE ability to throw objects fast and accurately helped to turn humans from a second-rate primate into one of the most successful species on the planet, a study suggests. Throwing enabled the ancestors of modern humans to defend themselves against dangerous predators, hunt big game, expand their diet, boost brain power and colonise almost every corner of the globe, scientists said. The skills that today enable top-class bowlers to deliver cricket balls at up to 100 mph are the result of key evolutionary adaptations to the torso, shoulders and arms which began nearly 2 million years ago, the researchers said. “We think that throwing was probably most important early on in terms of hunting behaviour, enabling our ancestors to effectively and safely kill big game,” said Neil Roach of George Washington University in Washington DC. “Eating more calorie-rich meat and fat would have allowed our ancestors to grow larger brains and bodies and expand into new regions of the world — all of which helped make us who we are today,” said Dr Roach, the lead author of the study published in the journal Nature. The researchers tracked the upper-body movements of American college baseball pitchers using 3-D cameras and computer animations. This revealed how the human shoulder acts much like a slingshot during a throw by storing and then suddenly released large amounts of energy. They found that compared to a chimpanzee, which can only throw objects at less than a third of the speed of a 12-year-old child, the human anatomy is finely tuned for the act of throwing. Dr Roach and his colleagues found that three crucial adaptations — a wide waist, a lower position of the shoulders on the torso and the ability to twist the upper arm bone — all occurred as early as nearly 2 million years ago, during the time of Homo erectus, our hominin ancestor. These three changes to the human anatomy enabled our early relatives to throw projectiles, such as rocks or wooden spears, at incredible speeds by storing and releasing energy in the tendons and ligaments crossing the shoulder. “This energy is used to catapult the arm forward, creating the fastest motion the human body can produce, and resulting in very rapid throws,” Dr Roach said. “When humans throw, we first rotate our arms backwards away from the target. It is during this ‘arm-cocking’ phase that humans stretch the tendons and ligaments crossing their shoulder and store elastic energy,” he said. “When this energy is released, it accelerates the arm forward, generating the fastest motion the human body produces, resulting in a very fast throw,” he added. The scientists believe that these evolutionary changes, which occurred long after the human and chimpanzee lineage diverged from the last common ancestor about 7.5 million years ago, were crucial to the subsequent development of humans into a large-brained creature with language and advanced tool-making skills. “Humans are remarkable throwers, and the only species that can throw objects fast and accurately. Chimpanzees, our closest living relatives, throw very poorly, despite being incredible strong and athletic,” Dr Roach said. “Adult male chimps for instance can only throw objects at about 20 mph, one-third of the speed of a 12-year-old little league pitcher,” he said. Homo erectus most likely used his new throwing skills to hunt big game and defend valuable carcasses against other predators. This expansion of diet enabled humans to build bigger brains, develop language and expand their geographic ranges. “Hunting had profound effects on our biology. For example, by improving diet quality our ancestors were able to grow larger brains leading to cognitive changes such as the origins of language,” Dr Roach said. “We think that hunting also probably changed the way our ancestors interacted with the world around them. For the first time, male and females likely divided their labour differently and shared food-getting tasks,” he said. “Surpluses of meat from a large kill could be shared or eaten over a number of days, freeing time for other activities. As our ancestors became more reliant on hunting they would also have been free to move into new environments that previously would not have had enough fruits and vegetables to sustain them. “This ability to move into new environments and thrive would have been crucial as our ancestors migrated out of Africa and spread throughout the world,” Dr Roach added. However, our innate throwing prowess is not to be abused. Premier league cricketers and baseball players throw far more frequently than our ancestor would ever have done during hunting and practising. This can lead to stretching and strains the human body is not able to cope with, Dr Roach explained. “At the end of the day, despite the fact that we evolved to throw, when we overuse this ability it can end up injuring us,” he said. — The Independent |
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Mystery behind wrinkles revealed BIOLOGISTS at the University of Sheffield have found an explanation as to how our skin constantly regrows. The research — conducted in collaboration with cosmetics firms — has implications for combating the effects of aging and perhaps even skin cancer. The team developed an “in silico” (computer) model of human skin biology, capturing how the outer layers of the skin are developed and maintained over time. This model simulation or “virtual” skin was then used to test the three most popular theories of how skin cells function to regenerate our skin, the largest human organ, over a three-year period. When the simulation was run according to two of the theories, the virtual skin failed to fully regenerate. Only one theory enabled the virtual skin to still be in good shape after three years, as Dr Xinshan Li (University of Sheffield Faculty of Engineering) and Dr Arun Upadhyay (P&G), the lead co-authors explained in their research. “The theory which seems to fit best says that skin has a population of ‘sleeping’ stem cells, which sit in the lowest layer of the skin but don’t constantly divide to make new cells,” Dr Li said. “However, these sleeping cells can be called into action if the skin is damaged, or if the numbers of other types of more mature skin cells decrease, ensuring that the skin can be constantly regenerated under all conditions,” the researcher said. The model showed that we gradually lose these sleeping stem cells over time, which would explain why our ability to regenerate our skin reduces as we age. “Each time we wake up these cells, to heal a wound or replenish stocks of other cells, a few of them don’t go back into sleep mode, so the population slowly reduces,” Dr Li said. “This explains why older skin is slower to heal and in part why our skin changes as we age. By understanding this mechanism better, it might be possible to find ways to combat the effects of aging on our skin,” Dr Li added. Computer modelling of skin biology is the latest step in the evolution of skin science. With the development of in silico models, scientists can predict for the first time what happens in skin as it ages year by year even as it ages decade by decade. The research is published in Nature Scientific Reports.
— ANI |
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Plants are good at maths, say scientists LONDON: Plants do complex arithmetic calculations to make sure they have enough food to get them through the night, new research published in journal eLife shows. Scientists at Britain’s John Innes Centre said plants adjust their rate of starch consumption to prevent starvation during the night when they are unable to feed themselves with energy from the sun. They can even compensate for an unexpected early night. “This is the first concrete example in a fundamental biological process of such a sophisticated arithmetic calculation,” mathematical modeler Martin Howard of John Innes Centre (JIC) said. During the night, mechanisms inside the leaf measure the size of the starch store and estimate the length of time until dawn. Information about time comes from an internal clock, similar to the human body clock. “The capacity to perform arithmetic calculation is vital for plant growth and productivity,” JIC metabolic biologist Alison Smith said. “Understanding how plants continue to grow in the dark could help unlock new ways to boost crop yield.”
CAPE CANAVERAL, Florida:
In deciding how to exhibit the space shuttle Atlantis, which goes on display from June 29, the Kennedy Space Center Visitor Complex in Florida opted for a perspective that would allow the public a rare view. “One of the ideas that developed very early was to show the orbiter as only astronauts had seen it — in space," said Bill Moore, chief operating officer with Delaware North Companies Parks and Resorts, which operates the visitors center for NASA at Cape Canaveral. The developers of the exhibit raised the 68,000-kg spaceship 30 feet into the air and tilted it 43 degrees over on its left side, simulating the vehicle in flight.
— Reuters |
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THIS UNIVERSE
Since Mercury is the nearest planet to the Sun, why is Venus called as the hottest planet? Mercury is a small planet without any atmosphere, or with a very thin atmosphere. Because of its closeness to the sun, the sunlit side gets extremely hot, but the other side quickly cools down and remains cool till it faces the sun again. Therefore, mercury does not retain the heat because of the lack of an atmosphere, does not get as uniformly hot as Venus which has a rather thick atmosphere. Venus is the prime example showing planets not to cover themselves with thick blankets of atmospheres, if they want a pleasant climate. What is the meaning of life? I think life is something that makes wonderful people like you ask me such profound questions. Thanks for being so alive. It is said that asteroids are the broken pieces of a planet that was not formed due to gravitational pull of Jupiter. Then, how was Saturn formed? I do not know whether to blame Jupiter for the break-up of a forming planet into the asteroidal belt but some such celestial accident was probably the cause. However, I do not see how we could blame Jupiter for engaging in all destructive happenings in its neighborhood. In any case, Saturn is too far and a bit too defuse. Readers can e-mail questions to Prof Yash Pal at palyash.pal@gmail.com |
