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 statements is true according to the passage（）
A. Mankind has moral restraints concerning fighting wars
B. Aggressive behaviors among chimps are due to genetic factors
C. Human beings are worrying about choosing between peace and war
D. Some chimps are much milder in temper than human beings
参考答案：A
解析：
[试题类型] 推理引申题。
[解题思路] 第六段中Mitani指出，有些人会从对黑猩猩的研究中得出结论：侵略的本性根深蒂固(the roots of aggression run very deep)，战争是进化的必然结果(war is our evolutionary destiny)，但他接着指出，人类依照道德行为准则行事，而黑猩猩没有这种准则(we operate by a moral code that chimps don’t have)，故选项[A]“在战争问题上，人类受到道德标准的约束”正确。
[干扰排除] 对于黑猩猩互相残杀的原因，文中仅提及了一种假设，即为了占领领地，并朱提及基因因素(genetic factors)，故排除选项[B]。选项[C]是对文章末段最后两句的曲解，此处提到，我们与战争及和平都是紧密相连的，而我们选择何种路线仍由我们自己决定(the route we choose is still up to us)，但并不能过度推出人类对选择和平还是战争感到忧虑，故排除选项[C]。文章最后一段仅比较了两种黑猩猩的好战程度，并指出，倭黑猩猩在处理群间关系时远没有普通黑猩猩那样具有攻击性(the latter...aren’t nearly as aggressive...)，由此可见，文中作者将两种黑猩猩的脾气进行了比较，并没有将人类与某些黑猩猩进行比较，选项[D]“有些黑猩猩在性情上比人类要温和得多”未提及，故排除。