It’s obvious that humans are fundamentally different from other animal species. It’s not so easy, though, to identify the traits that make human beings so special. Scientists realized long ago that other animals make tools, play jokes and even have a sense of justice and altruism—all things we once thought were unique to our species.
Now a paper in the journal Current Biology has added another behavior to the list of what other animals share with us—and this one isn’t quite so charming. After years of field observations in Uganda’s Kibale National Park, John Mitani of the University of Michigan and several colleagues have concluded that chimps wage war to conquer new territory.
"We already knew that chimps kill each other," says Mitani. "We’ve known this for a long time." What scientists didn’t know for certain, at least in cases in which groups of chimps banded together to kill others, was why. One hypothesis, advanced more than a decade ago by anthropologist Richard Wrangham, was the idea of territorial conquest; circumstantial evidence from both Gombe and Mahale national parks in Tanzania bolstered the theory.
In Mahale, for example, male members of one group mysteriously vanished, and another group then expanded into what had been their land. In Gombe, an existing group dissolved into civil war, resulting in killings and land takeovers.
What’s especially chilling about the observation is that the murder rate appears to be so high. The anthropologists couldn’t be certain of how big a band the victims belonged to because they weren’t used to a human presence and thus couldn’t be accurately counted. But even a conservative estimate suggests that the death rate is significantly higher than you would see in war between human hunter-gatherer groups.
Mitani isn’t oblivious to the lesson some people might draw from the study. "Invariably, some will take this as evidence that the roots of aggression run very deep," he says, and therefore conclude that war is our evolutionary destiny. "Even if that were true," says Mitani, "we operate by a moral code that chimps don’t have."
Apart from that, he points out, the Pan troglodytes chimps he studies are one of two subspecies. The other is called Pan paniscus, also known as bonobos, and, says Mitani, "the latter, as far as we know, aren’t nearly as aggressive with respect to intergroup relations. Yet they’re equally close to us." That means that if we’re wired for warfare, we’re wired for peace too. Ultimately, the route we choose is still up to us.
John Mitani concludes that chimps（）
A. are hard to approach under some circumstances
B. tend to be aggressive against others on some occasions
C. have many similar traits as human beings
D. may kill each other for some reasons unknown
参考答案：B
解析：
[试题类型] 具体信息题。
[解题思路] 根据题干关键词John Mitani concludes定位到文章第二段未句。该句指出，三谷(Mitani)和他的几位同事得出结论：为了占领新领地，黑猩猩也会开战(chimps wage war to conquer new territory)，由此可见，选项[B]“黑猩猩在某些时候会对其他成员具有攻击性”与原文意思相符，故为答案。
[干扰排除] 原文中三谷得出的结论是黑猩猩在某些情况下会开战，而不是在某些情况下难以接近(hard to approach)，故排除选项[A]。由文中第二段可知，三谷及其同事经过若干年野外观察，发现了黑猩猩与人类近似的一种行为，即会为了占领新领地而发动战争，这只是三谷发现的黑猩猩同人类共有的一个习性，至于黑猩猩与人类是否有很多相似的特性(many similar traits)，从三谷的研究中无法推知，故排除选项[C]。文章第二段未句提到，三谷提出结论：黑猩猩开战的原因是为了占领新领地，故选项[D]“黑猩猩杀害彼此的原因不详”不符合题干。