26 ноября 2002 г.
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Новости науки и техники в "Scientific American"
26 ноября 2002 г. |
DNA STUDY TRACES FIDO'S FAMILY TREEThe dog has long been considered man's best friend. Now new findings may explain just when humans first domesticated canines. Today's dogs, it seems, originated from East Asian wolves about 15,000 years ago.TOP SCITECH GIFTS 2002Still haven't found presents for the science fans on your list? Before you brave the cold and the holiday crowds again, take a look at our favorite 20 geek gifts to give and get this year.BOOKSTORE: THE EMERGENCE OF EVERYTHING: HOW THE WORLD BECAME COMPLEX by H.J. MorowitzWhen the whole is greater than the sum of the parts - indeed, so great that the sum far transcends the parts and represents something utterly new and different - we call that phenomenon emergence. When the chemicals diffusing in the primordial waters came together to form the first living cell, that was emergence. When the activities of the neurons in the brain result in mind, that too is emergence. In The Emergence of Everything, one of the leading scientists involved in the study of complexity, Harold J. Morowitz, takes us on a sweeping tour of the universe, a tour with 28 stops, each one highlighting a particularly important moment of emergence.WELL WATER ARSENIC TESTS GO AWRY IN BANGLADESHArsenic contamination of well water in Bangladesh is a widespread problem, the enormity of which came to light in 1998 at an international conference that determined that tens of millions of people had suffered exposure that put their health at risk. As a result, individual wells were tested to determine whether the water they provide is safe to drink. New research suggests that close to a third of the wells were labeled incorrectly.SECOND PIECE OF FOSSIL FORGERY IDENTIFIEDDiscovered in 1999, the fossil Archaeoraptor was briefly believed to be the missing link between dinosaurs and birds. Shortly after its unveiling, however, it was determined that Archaeoraptor was instead a fake, probably comprised of up to five specimens of two or more different species. In 2000, scientists identified its tail as that of a Microraptor dinosaur from the early Cretaceous period. New work classifies the rest of the faked fossil as the remains of a fish-eating bird.WASPS TAMPER WITH PLANT CHEMISTRY TO WOO MATESA tiny wasp no bigger than a flea can change the chemistry of plants to help it land a mate, according to a new study. Researchers have discovered that the gall wasp (Antistrophus rufus) alters the ratio of certain compounds within a plant's stem to attract members of the opposite sex.ASK THE EXPERTS: WHY DOES A SHAKEN SODA FIZZ MORE THAN AN UNSHAKEN ONE?Chemist Chuck Wight of the University of Utah explains.