单选题
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 have 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 changes. No other species fills so many places in nature. But in the past 100,000 years even the past 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 "look at an organic being as average looks at a ship, as at something wholly beyond his comprehension". 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.
单选题
What used to be the danger in being a man according to the first paragraph?
【正确答案】
C
【答案解析】[解析] 文章第一段开头是答题的关键:Being a man has always been dangerous...But the great universal of male mortality is being changed. 可见,男性的出生率高于女性,但是随着年龄增加,男女比例呈明显下降趋势。作者试图用这些数据表明,生为男人的危险并不是在于寻找配偶的困难,而是男性的死亡率(male mortality)远远高于女性。
单选题
What does the example of India illustrate?
【正确答案】
B
【答案解析】[解析] 根据第二段最后两句话“The country offers wealth for a few...in upper-middle-class India compared to the tribes. ”(这个国家为少数大城市的人提供了大量的财富,而其他的部落人却很贫穷。今天每个人都有大体相同的存活率和后代人数,这就意味着与部落相比,自然选择在中高阶级印第安人中已经失去了80%的效力。)这与B中“Natural selection hardly works among the rich and the poor”的意思相吻合。
单选题
The author argues that our bodies have stopped evolving because ______.
【正确答案】
A
【答案解析】[解析] 在第三段中作者写道:“We did not evolve, because machines and society did it for us. ”换言之,机器的使用、社会的进步使我们的生活发生了变化,即A“技术的进步提高了生活质量”。
单选题
The word "Utopia" in Paragraph 3 most closely means ______.
【正确答案】
B
【答案解析】[解析] Utopia的意思是“完美的社会”。
单选题
Which of the following would be the best title for the passage?
【正确答案】
D
【答案解析】[解析] 全文主旨题。文章最后一段对全文内容进行了总结:“For us, this means that evolution is over; the biological Utopia has arrived. (这意味着进化已经结束。)”最后作者说,“But however amazed our descendants may be at how far from Utopia we were, they will look just like us. ”这进一步说明,人类的进化早已经停止。