2000年考研英语56题

Passage 2
Being a man has always been dangerous. There are about 105 males born for every 100 females, but this ratio drops to near balance at the age of maturity, and among 70-year-olds there are twice as many women as men. But the great universal of male mortality is being changed. Now, by babies survive almost as well as girls do. This means that, for the first time, there will be an excess of boys in those crucial years when they are searching for a mate. More important, another chance for natural selection has been removed. Fifty years ago, the chance of a baby (particularly a boy baby) surviving depended on its weight. A kilogram too light or too heavy meant almost certain death. Today it makes almost no difference. Since much of the variation is due to genes one more agent of evolution has gone.
There is another way to commit evolutionary suicide: stay alive, but have fewer children. Few people are as fertile as in the past. Except in some religious communities, very few women has 15 children. Nowadays the number of births, like the age of death, has become average. Most of us have roughly the same number of offspring. Again, differences between people and the opportunity for natural selection to take advantage of it have diminished. India shows what is happening. The country offers wealth for a few in the great cities and poverty for the remaining tribal peoples. The grand mediocrity of today everyone being the same in survival and number of offspring means that natural selection has lost 80% of its power in upper-middle-class India compared to the tribes.
For us, this means that evolution is over; the biological Utopia has arrived. Strangely, it has involved little physical change No other species fills so many places in nature. But in the pass 100,000 years even the pass 100 years our lives have been transformed but our bodies have not. We did not evolve, because machines and society did it for us. Darwin had a phrase to describe those ignorant of evolution: they %26quot;look at an organic being as average looks at a ship, as at something wholly beyond his comprehension.%26quot; No doubt we will remember a 20th century way of life beyond comprehension for its ugliness. But however amazed our descendants may be at how far from Utopia we were, they will look just like us.
56.What does the example of India illustrate?
〔A〕Wealthy people tend to have fewer children than poor people.
〔B〕Natural selection hardly works among the rich and the poor.
〔C〕The middle class population is 80% smaller than that of the tribes.
〔D〕India is one of the countries with a very high birth rate

我认为没有答案……
印度的例子只能说明“富人当中自然选择作用不大”，不能说明穷人的情况。还有，如果c选项的The middle class population 改成The upper-middle class population 以与原文一致，那么它就是正确的。理由：自然选择在富人中的作用是穷人中的80%，而人口越多自然选择的效果就越明显，所以如果只考虑文中提到的因素，中上等阶级人口比穷人少80%的结论是靠得住的。
打错字了，我想说的是：
“‘自然选择在富人中的作用比穷人中的少80%’，而人口越多自然选择的效果就越明显，所以如果只考虑文中提到的因素，中上等阶级人口比穷人少80%的结论是靠得住的。”
至于参考答案b，自然选择在穷人中不起作用的论据是什么呢？根据natural selection has lost 80% of its power in upper-middle-class India compared to the tribes这句是得不到这种结论的。

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