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 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 year 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] 本题可参照文章的第1段。身为男人，总是有危险。男女出生比率大约为105:100，但到成年时，这种比率下降，几乎达到平衡，在70岁的老年人中，女性比男性多一倍。可是男性死亡率普遍高的现象正在改变。如今的男婴同女婴和存活率一样。这意味着，男孩到了寻找伴侣的关键年龄，将第一时间出现男孩过剩现象。更重要的是，自然选择的另一个偶然性失去了作用。50年前，婴儿(尤其是男婴)存活下来的几率取决于其体重。轻一公斤或重一公斤都几乎代表着必死无疑。体重在今天几乎不起作用。由于很多差别是由基因引起的，因而又一个进化因素消失了。据此可知，以前，男性面临的危险是死亡率普遍高。C项与文章的意思相符，因此C项为正确答案。

单选题 What does the example of India illustrate?

【正确答案】 B

【答案解析】[解析] 本题可参照文章的第2段。从中可知，如今很少人像从前那样能生育了。除了在一些宗教群体，很少有妇女生15个孩子。今天所生孩子的数目就像死亡年龄一样，人人都差不多。我们大多数人家的子女数量几乎都一样多。人与人之间的差异和利用差异进行自然选择的机会再次减小。印度的情况就是这样。该国为大城市的一部分人提供财富，而其余那些仍保持群居的部落民族依然贫困。今天最大的相同点——每个人的生存机会和子女数量都一样——意味着，与部落比较，自然选择在印度中上阶层已失去80%的作用。据此可知，印度的例子说明——在印度，自然选择在穷人和富人之间所起的作用大大降低了。B项与文章的意思相符，因此B项为正确答案。

单选题 The author argues that our bodies have stopped evolving because ______.

【正确答案】 A

【答案解析】[解析] 本题可参照文章的第3段。从中可知，对于我们来说，这意味着进化已结束；生物学上的理想境界已经来临；令人奇怪的是，这种进化几乎不涉及身体的变化；过去10万年——甚至过去100年中，我们的生活发生了改变，但我们的身体却没有；我们没有进化，因为机器和社会代替我们进化了。据此可知，我们的身体已经停止进化的原因是机器和社会代替我们进化了，也就是先进的技术代替我们进化了。A项与文章的意思相符，因此A项为正确答案。

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] 从文章第1段的内容可知，如今的男婴和女婴的存活率几乎一样；这就意味着，自然选择的另一个偶然性已经被消除了；因为大部分的变异是由基因引起的，所以进化的又一个因素不存在了；从第2段的内容可知，如今，几乎没有人像过去那样能生育了；现在，出生的人数已经平均化；我们大多数人所生的子女数量几乎一样多；人与人之间的差别以及利用这种差别进行自然选择的机会都已经减少；每个人的寿命差不多，所生的子女数量也一样；从文章最后一段的内容可知，对于我们来说，这意味着进化已经结束了；生物学上的理想境界已经来临；过去10万年——甚至过去100年，我们的生活发生了变化，但我们的身体却没有改变；我们没有进化，因为机器和社会代替我们进化了；无论我们的后代感到多么惊奇，他们还是会看起来跟我们一样。据此可知，本文主要讲的是：由于一些进化因素的消失，人类的进化已经结束了。D项与文章的意思相符，因此D项为正确答案。