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| SCIENCE & TECHNOLOGY |
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Was ‘Hobbit’ for real? Prof Yash
Pal
THIS UNIVERSE
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Was ‘Hobbit’ for real? She was either a new species of miniature “Hobbit-like” human, just three feet tall, who lived 18,000 years ago on a remote Indonesian island among giant rats, pygmy elephants and massive, dragon-like reptiles. Or she was just another member of our own species - Homo sapiens - who was unfortunate enough to suffer from a severe congenital disorder that meant she developed an unusually small braincase, stunted body and shortened limbs. If the latter is ever proved to be the case, it will come as a huge embarrassment to the scientists behind a study published in the journal Nature in 2004, claiming that Homo floresiensis truly represents a new species of miniature human being. The latest salvo in the dispute over the bones has come in a study published in the current issue of the journal Proceedings of the National Academy of Science, which backs up claims that the “hobbit” is nothing more than a small-brained member of our own species. The authors of the study claim that the original assessment of the remains was wrong, and that there is no evidence for the existence of a miniature species of human who hunted pygmy rats and who was in turn hunted by giant Komodo dragons. The dispute over the bones of the “hobbit” broke out almost as soon as the details of its existence emerged in a groundbreaking piece of research that, it is fair to say, set the world of palaeo-anthropology alight. A team of Indonesian and Australian scientists had found a partial skeleton of a creature they labelled LB1, the first human from Liang Bua cave on the island of Flores. What was unique and utterly amazing about the individual — apparently an adult female, although the original artist’s impression that accompanied the research, was drawn depicting a male — was that she must have lived with a skull containing a braincase no bigger than a grapefruit — about a third of the size of that of modern-day humans. She would have also stood barely three feet high. Being this height is not in itself unusual. Some modern-day pygmies are this height, a dwarfism that results from lacking the typical adolescent growth spurt of non-pygmy humans. But the head size — and braincases — of modern pygmies still fall within the normal range of the other members of Homo sapiens. But the “hobbit”, as the female at Liang Bua cave was nicknamed, had a far smaller head that was more in proportion with her body. Prof Mike Morwood of the University of New South Wales in Armidale, a leading member of the team, said at the time that he could not believe what he and his colleagues had found — especially given that the carbon dating pointed to the creatures still living on Flores as recently as 13,000 years ago. “It is a new species of human who actually lived alongside us, yet were half our size. They were the height of a three-year-old child, weighed around 25 kilos [4 stones] and had a brain smaller than most chimpanzees,” Professor Morwood said in 2004. “Even so, they used fire, made sophisticated stone tools and hunted stegadon — a primitive type of elephant — and giant rats. We believe that their ancestors may have reached the island using bamboo rafts. The clear implication is that, despite tiny brains, these little humans were intelligent and almost certainly had language,” Professor Morwood said. For evolutionary biologists, the discovery pointed to the first case of endemic island dwarfism in humans. Animals isolated on a remote island can evolve into giants — like the Flores rat — or pygmies, such as the stegadon. “Although a common feature of large mammals in insular environments, this has never been recorded for a human relative before,” said Peter Brown of the University of New England, another leading member of the
team. Archaeological evidence suggests that the Liang Bua cave was inhabited by early humans of some description for about 800,000 years. Archaeologists have also found relatively sophisticated stone tools in the cave that appear similar to those made at other sites in the world by an earlier species of human called Homo erectus. However, the crucial difference between Homo erectus tools and those at Liang Bua is that the Flores cave artifacts are far smaller — suggesting that they were honed by the tiny hands of the miniature humans. “Finding these hominins on an isolated island in Asia, and with elements of modern human behaviour in tool-making and hunting, is truly remarkable and could not have been predicted by previous discoveries,” Professor Brown
said. By arrangement with The Independent, London |
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Woolly mammoth may come back
The woolly mammoth and other creatures long extinct may be set to make a comeback on earth and not just in Hollywood films like ‘Jurassic Park’. Research has indicated that sperm recovered from mice frozen for 15 years is still capable of producing babies. The finding could help fertility researchers using animal models and those attempting to create libraries of endangered species by giving them a simpler, more effective method to put DNA in a deep freeze. It could even offer hope to those attempting to reawaken creatures such as the woolly mammoth, says Nature magazine. Researchers currently harvest sperm by dissecting dead animals and isolating sperm from the epididymis, the site of sperm storage in the testes. The sperm is then purified and frozen in solution along with various chemicals that help to protect the cells’ structure from the trials of freezing. When the time comes, samples are thawed out and injected into eggs for fertilisation. The procedure works reasonably well even though the sperm is not alive and swimming, Nature reported. Much the same storage technique can be used for human sperm — some samples have been frozen for more than 20 years and still produced healthy babies. The procedure is not ideal, however. It can get somewhat arduous when dealing with masses of frozen animal sperm, and freezing can sometimes damage the valuable DNA cargo. Success rates vary from less than 1 per cent to 30 per cent.
— PTI |
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THIS UNIVERSE
How do power saver lamps differ from tungsten filament lamps or the fluorescent tubes that require a
special holder and starter? Please explain in a simple language so that a matriculate can understand. A tungsten filament bulb depends on the light emitted by its very hot filament of tungsten wire. Most of the energy consumed by the lamp goes into heat. That is the primary reason for the fact that they consume so much power. The fluorescent tubes were the first attempt to get more light from the same amount of power consumption. These tubes are gas discharge tubes with some mercury vapour inside. The gas discharge produces mostly ultra violet radiation that, falling on the phosphor coated on the inner walls of the tube, produces light. In order to start the discharge, we need a “ballast” that gives a high voltage initiating pulse. After the discharge starts, the electron-emitting filament is kept hot by the impact of discharge ions. The ballast used for these tubes is traditionally magnetic. This is responsible for the flicker during start up and some noise during operation. The modern high efficiency lights are also discharge tubes, but the ballast is electronic and very compact. It is often hidden in the base of the lamp. There is no flicker and we get a quick start. If I move an iron nail slowly near to a magnet, at some point the nail will leap forward and stick to the
magnet. Where does the energy come from to overcome inertia and friction and move the nail? I would advise you to think of a stone lying on an inclined plane and restrained by your hand. When you let go, the ball starts rolling in the downward direction. Where does the energy come from to overcome inertia and the friction? You would immediately reply it is the potential gravitational energy. In simple words, there is an attraction between the ball and the Earth and the ball wants to get as close to the center of the Earth as it can. The potential energy is converted into kinetic energy. If you want to move the ball back to its original position you will have to do work. Similarly, the iron nail and the magnet attract each other. At some distance, the attraction might be too little to lift the nail, but when the distance between the two is reduced, the attractive force is enough to make the iron nail fly towards the magnet, the force between them getting stronger as these approach each other. Here also if you want to move the nail back to its original position, you will have to exert some force. The laws of force might be different, but the dynamics is similar. |
It is either the most important discovery in human evolution for decades, or one of the biggest blunders of modern science — and there’s not much room for anything in between.