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.
Which of the following would be the best title for the text（）
A. Chimps Going to War Too
B. Higher Death Rate among Chimps
C. Differences between subspecies of Chimps
D. Traits Unique to Human Beings
参考答案：A
解析：
[试题类型] 主旨要义题。
[解题思路] 纵观全文，文章第一段首先指出人类与其他动物物种有着根本的不同，接着笔锋一转，第二段就提出了人类与黑猩猩共有的一种行为：为了争夺领地而战。第三段到第七段说明了科学家们得出这一结论的过程：首先提出假设，然后用实例证明假设，最后得出结论。由此可见，整篇文章都是围绕黑猩猩开战展开的，这也是文章的主题，选项[A]的含义与此相符。
[干扰排除] 文章第五段提到了黑猩猩互相残杀时的高谋杀率(murder rate appears to be so high)，但这只是科学家在研究黑猩猩之间战争时的发现之一，不足以概括文章大意，故排除选项[B]。文章在最后一段提到了黑猩猩的两个亚种(two subspecies)，普通黑猩猩和倭黑猩猩，并对其好战性进行了比较，但这属于文章细节，不是主要讨论的内容，故排除选项[C]。选项[D]的含义为“人类特有的特征”，全文论述的中心为黑猩猩，而非人类，故排除该选项。