【正文】 ren.” 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 there’s no question that it’s also fun. “Animals at play are symbols of the unfettered joy of life,” he says 11. Grief also seems to be mon in the wild, particularly following the death of a mate, parent, offspring, or even close panion. 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 bird’s 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 nature’s bestknown 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 animal’s 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 “l(fā)eaves me with little doubt that they experience deep emotions and have some understanding about death.” there’s “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. most important emotional site identified so far is the amygdala, an almondshape 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, brainimaging 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.” 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 uping play session, it would bee “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 opiates–chemicals that, like dopamine, are thought to be involved with pleasure in people. 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 oxytocin’s 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.” is it love, really? Bernd Welsig, the Texas Aamp。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 ‘a(chǎn)lternative 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 it’s in love, but you can’t prove what it’s 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 selfawareness,” he says, “the movie we call consciousness is not there.” Richard Davidson, a neuroscientist at the University of WisconsinMadison, agrees that higher primates, including apes and chimps, are the only animals that have demonstrated selfconsciousness 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, es from the theory of evolution, widely accepted by biologists of all stripes. C