新世纪研究生公共英语教材B 11 13单元.doc

B:第九单元Animal EmotionsLaura TangleySheer joy. Romantic love. The pain of mourning. Scientists say pets and wild creatures have feelings, too.1.Swimming off the coast of Argentina, a female right whale singles out just one of the suitors that are hotly pursuing her. After mating, the two cetaceans linger side by side, stroking one another with their flippers and finally rolling together in what looks like an embrace. The whales then depart, flippers touching, and swim slowly side by side, diving and surfacing in perfect unison until they disappear from sight.2. In Tanzania, primatologists studying chimpanzee behavior recorded the death of Flo, a troops 50-year-old matriarch. Throughout the following day, Flos son, Flint, sits beside his mothers lifeless body, occasionally taking her hand and whimpering. Over the next few weeks, Flint grows increasingly listless, withdrawing from the troop despite his siblings efforts to bring him backand refusing food. Three weeks after Flos death, the formerly healthy young chimp is dead, too.3.A grief-stricken chimpanzee? Leviathans in love? Most people, raised on Disney versions of sentient and passionate beasts, would say that these tales, both true, simply confirm their suspicions that animals can feel intense, humanlike emotions. For their part, the nations 61 million pet owners need no convincing at all that pet dogs and cats can feel angry, morose, elated even jealous or embarrassed. Recent studies, in fields as distant as ethology and neurobiology, are supporting this popular belief. Other evidence is merely anecdotal, especially for pets dogs that become depressed, or even die, after losing a beloved companion, for instance. But the anecdote or case study in scientific parlance has now achieved some respectability among researchers who study animal behavior. As University of Colorado biologist Marc Bekoff says, “The plural of anecdote is data.”4.Still, the idea of animals feeling emotions remains controversial among many scientists. Researchers skepticism is fueled in part by their professional aversion to anthropomorphism, the very nonscientific tendency to attribute human qualities to non-humans. Many scientists also say that it is impossible to prove animals have emotions using standard scientific methods repeatable observations that can be manipulated in controlled experiments leading them to conclude that such feelings must not exist. Today, however, amid mounting evidence to the contrary, “the tide is turning radically and rapidly,” says Bekoff, who is at the forefront of this movement.5.Even the most strident skeptics of animal passion agree that many creatures experience fear which some scientists define as a “primary” emotion that contrasts with “secondary” emotions such as love and grief. Unlike these more complex feelings, fear is instinctive, they say, and requires no conscious thought. Essential to escape predators and other dangers, fear and its predictable flight, fight, or freeze responses seems to be hard-wired into many species. Young geese that have never before seen a predator, for example, will run for cover if a hawk-shaped silhouette passes overhead. The shape of a nonpredatory bird, on the other hand, elicits no such response.6.But beyond such instinctual emotions and their predictable behavioral responses, the possibility of more complex animal feelings those that entail mental processing is difficult to demonstrate. “I cant even prove that another human being is feeling happy or sad,” says Bekoff, “but I can deduce how theyre feeling through body language and facial expression.” As a scientist who has conducted field studies of coyotes, foxes, and other canines for the past three decades, Bekoff also believes he can accurately tell what these animals are feeling by observing their behavior. He adds that animal emotions may actually be more knowable than those of humans, because they dont “filter” their feelings the way we do.7. Yet because feelings are intangible, and so tough to study scientifically, “most researchers dont even want to talk about animal emotions,” says Jaak Panksepp, a neuroscientist at Bowling Green State University in Ohio and author of Affective Neuroscience. Within his field, Panksepp is a rare exception, who believes that similarities between the brains of humans and other animals suggest that at least some creatures have true feelings. “Imagine where wed be in physics if we hadnt inferred whats inside the atom,” says Panksepp. “Most of what goes on in nature is invisible, yet we dont deny that it exists.”8. The new case for animal emotions comes in part from the growing acceptability of field observations, particularly when they are taken in aggregate. The latest contribution to this body of knowledge is a new book, The Smile of a Dolphin, which presents personal reports from more than 50 researchers who have spent their careers studying animals from cats, dogs, bears, and chimps to birds, iguanas, and fish. Edited by Bekoff, who says it will finally “legitimize” research on animal emotions, the volume has already garnered scientific attention, including a Smithsonian Institution symposium on the subject.9. One of the most obvious animal emotions is pleasure. Anyone who has ever held a purring cat or been greeted by a bounding, barking, tail-wagging dog knows that animals often appear to be happy. Beastly joy seems particularly apparent when the animals are playing with one another or sometimes, in the case of pets, with people.10.Virtually all young mammals, as well as some birds, play, as do adults of many species such as our own. Young dolphins, for instance, routinely chase each other through the water like frolicsome puppies and have been observed riding the wakes of boats like surfers. Primatologist Jane Goodall, who has studied chimpanzees in Tanzania for four decades, says that chimps “chase, somersault, and pirouette around one another with the abandon of children.” In Colorado, Bekoff once watched an elk race back and forth across a patch of snow even though there was plenty of bare grass nearby leaping and twisting its body in midair on each pass. Though recent research suggests that play may help youngsters develop skills needed in adulthood, Bekoff says theres no question that its also fun. “Animals at play are symbols of the unfettered joy of life,” he says11. Grief also seems to be common in the wild, particularly following the death of a mate, parent, offspring, or even close companion. Female sea lions witnessing their pups being eaten by killer whales are known to actually wail. When a goose, which mates for life, loses its partner, the birds head and body droop dejectedly. Goodall, who saw the young chimp Flint starve after his mother died, maintains that the animal “died of grief.”12. Elephants may be natures best-known mourners. Scientists studying these behemoths have reported countless cases of elephants trying to revive dead or dying family members, as well as standing quietly beside an animals remains for many days, periodically reaching out and touching the body with their trunks. Kenyan biologist Joyce Poole, who has studied African elephants since 1976, says these animals behavior toward their dead “leaves me with little doubt that they experience deep emotions and have some understanding about death.”13.But theres “hard” scientific evidence for animal feelings as well. Scientists who study the biology of emotions, a field still in its infancy, are discovering many similarities between the brains of humans and other animals. In animals studied so far, including humans, emotions seem to arise from ancient parts of the brain that are located below the cortex, regions that have been conserved across many species throughout evolution.14.The most important emotional site identified so far is the amygdala, an almond-shape structure in the center of the brain. Working with rats, neuroscientists have discovered that stimulating a certain part of the amygdala induces a state of intense fear. Rats with damaged amygdalas, on the other hand, do not show normal behavioral responses to danger (such as freezing or running) or the physiological changes associated with fear higher heart rate and blood pressure, for example.15. In humans, brain-imaging studies show that when people experience fear, their amygdalas, too, are activated. And just like the rats, people whose amygdalas are damaged by accident or disease seem unable to be afraid when the situation warrants it. In humans and rats, at least, amygdalas are “basically wired the same way,” says New York University neuroscientist Joseph LeDoux, whose lab conducted much of the rat research. He adds that beyond fear, “the evidence is less clear, but the amygdala is implicated in other emotions as well.”16.The case for animal emotions is also bolstered by recent studies of brain chemistry. Steven Siviy, a behavioral neuroscientist at Gettysburg College in Pennsylvania, has found that when rats play, their brains release copious amounts of dopamine, a neurochemical that is associated with pleasure and excitement in humans. In one experiment, Siviy placed pairs of rats in a distinctive plexiglass chamber and allowed them to play. After a week, he could put one animal alone in the chamber and, anticipating its upcoming play session, it would become “very active, vocalizing, and pacing back and forth with excitement.” But when Siviy gave the same animal a drug that blocks dopamine, all such activity came to a halt. Neuroscientist Panksepp has found evidence that rats at play also produce opiateschemicals that, like dopamine, are thought to be involved with pleasure in people.17.Another chemical, the hormone oxytocin, is associated with both sexual activity and maternal bonding in people. It is released, for example, when mothers are nursing their infants. Now it looks as though the same hormone affects attachment among animals, at least in the case of a mouselike rodent called the prairie vole. To investigate oxytocins role in social bonding, University of Maryland neuroscientist C. Sue Carter targeted the vole because it is one of the few mammal species known to be monogamous. She found that females, who normally spend about a day selecting a mate from a pool of eager males, will choose one within an hour often the first male they see if they have first received an injection of oxytocin. Voles given a drug that blocks oxytocin, however, will not select a mate, no matter how much time they have. Carter concludes that pair bonding in voles relies at least in part on oxytocin, which produces behavior that looks much like people who are “falling in love.”18.But is it love, really? Bernd Welsig, the Texas A&M University biologist who observed amorous right whales off the coast of Argentina, believes that, as a scientist, “I should probably call this event a mere example of an alternative mating strategy. “ But Welsig still entertains the possibility that the cetaceans behaved the way they did because “they were the right right whales for each other.”19. Skeptics remain unconvinced. “A whale may behave as if its in love, but you cant prove what its feeling, if anything,” says neuroscientist LeDoux, author of The Emotional Brain. He maintains that the question of feelings boils down to whether or not animals are conscious. And though animals “may have snapshots of self-awareness,” he says, “the movie we call consciousness is not there.” Richard Davidson, a neuroscientist at the University of Wisconsin-Madison, agrees that higher primates, including apes and chimps, are the only animals that have demonstrated self-consciousness so far. Still, he believes that there are other creatures that “may at least have antecedents of feelings.”20. Or probably more, say Bekoff and his colleagues. Their most convincing argument, perhaps, comes from the theory of evolution, widely accepted by biologists of all stripes. Citing similarities in the brain anatomy and chemistry of humans and other animals, neuroscientist Siviy asks: “If you believe in evolution by natural selection, how can you believe that feelings suddenly appeared, out of the blue, with human beings?” Goodall says scientists who use animals to study the human brain, then deny that animals have feelings, are “illogical.”21. In the end, what difference does it really make? According to many scientists, resolving the debate over animal emotions could turn out to be much more than an intellectual exercise. If animals do indeed experience a wide range of feelings, it has profound implications for how humans and animals will interact in the future. Bekoff, for one, hopes that greater understanding of what animals are feeling will spur more stringent rules on how animals should be treated, everywhere from zoos and circuses to farms and backyards.22. But if there is continuity between the emotional lives of humans and other animals, where should scientists draw the line? Michel Cabanac, a physiologist at Laval University in Quebec, believes that consciousness arose when animals began to experience physical pleasure and displeasure. In experiments with iguanas, he discovered that the animals show physiological changes that are associated with pleasure in mammals a rise in body temperature and heart rate whereas frogs and fish do not. He proposes that emotions evolved somewhere between the first amphibians and reptiles. Yet even enthusiasts dont ascribe emotions to the very bottom end of the food chain. Says Bekoff: “Were not going to talk about jealous sponges and embarrassed mosquitoes.”动 物 的 情 感 劳拉·坦利非常的开心。浪漫的爱情。悲恸的哀悼。科学家说宠物和野生动物也有情感。1.一只在阿根廷海岸附近的水域中游动的露脊鲸，在众多热烈追求她的求偶者中只选出一名幸运儿。“完婚”之后，两头露脊鲸并排在水中徜徉，它们用鳍肢相互抚摩，最后又一起在水中滚动，看上去就像在互相拥抱。然后，两头露脊鲸开始游向远方，鳍肢相互触摸，慢慢并排游动，一会潜入水中，一会又浮出水面，它们动作完美和谐，直至最终在视线中消失。2.在坦桑尼亚，致力于研究黑猩猩行为的灵长类动物学家记录了一个黑猩猩群落中享年50岁的“女族长”弗洛死后发生的一些事情。弗洛的儿子弗林特第二天一整天都坐在母亲的尸体旁边，有时还会抓住她的手发出几声呜咽。在此后的几个星期里，弗林特的情绪越来越低落，他离群索居并且不再进食，尽管他的兄弟姐妹设法想让他回到群体中来。终于，在弗洛死后的第3个星期，原本年轻健康的黑猩猩弗林特也死了。3.悲伤过度的黑猩猩？坠入情网的海洋巨兽？很多人，由于深受迪斯尼卡通片中感性多情的动物形象的影响，会说这两个真实的故事更加证实了他们认为动物有人类般强烈情感的看法。从他们的角度来看，全国六千一百万拥有宠物的人完全不需要提供什么证据来证实宠物狗和宠物猫会生气、郁闷、得意洋洋甚至会嫉妒或困窘。最近在动物行为学和神经生物学之类的边缘学科的研究证实了这种普遍看法。其他的证据只是些轶事趣闻，特别是一些有关宠物的事，例如狗会在失去心爱的同伴后，变得沮丧，甚至死去。但是轶事趣闻或用科学的术语称之为案例研究现在已经获得了研究动物行为的研究人员的重视。正如科罗拉多大学的生物学家马克·贝科夫所说：“大量的轶事趣闻就是数据。”4.但是，许多科学家仍然对动物也有情感的观点持有异议。研究人员之所以会表示怀疑，部分原因是他们出于职业习惯讨厌拟人论，因为他们认为这是一种将人类的特性强加在非人类生物身上的毫无科学根据的主观倾向。许多科学家还认为用标准的科学方法（在受控实验环境下可进行重复观察）是无法证明动物是有情感的这使他们得出结论，认为这些所谓的动物情感一定不存在。但是动物情感论的积极倡导者贝科夫指出，如今面对越来越多的相反证据，“这场运动的潮流正在根本性地迅速转向”。 5.甚至连那些对动物情感论持绝对怀疑态度的人也承认，许多动物有恐惧感一些科学家认为，恐惧是与爱和悲伤等“中级”情感相对的“初级”情感。他们认为，与较为复杂的“中级”情感相比，恐惧是一种本能，它不需要任何有意识的思维。恐惧及其可以预见的逃跑、搏斗或者呆住不动的反应，是逃避食肉动物和其他危险所必需的，它看起来好像是许多动物与生俱来的本领。例如，以前从未见过食肉动物的小鹅如果看到形状像老鹰一样的黑影从头顶掠过就会马上跑去寻找藏身处。而另一方面，非食肉鸟的形状就不会引发这样的反应。6.但是，除了这些具有本能性质的情感及其可以预见的行为反应之外，科学家很难证明动物可能拥有更