2018专四阅读理解练习：人类进化已结束

2017-08-24 15:05:08来源：网络

2018专四阅读理解练习：人类进化已结束

2018专四阅读理解练习汇总

　　Being a man hasalways been dangerous. Thereare about 105 males born for every 100 females,butthis ratio drops to near balance at the age ofmaturity, and among70-year-olds there are twice asmany women as men. But the great universalofmale mortality is being changed. Now, boy babiessurvive almost as well as girlsdo. This means that, for the first time, there will be an excess ofboys inthose crucial years when they are searching for a mate. More important, anotherchancefor natural selection has been removed. Fifty years ago, the chance of ababy(particularly a boybaby) surviving depended on its weight. A kilogram toolight or too heavy meant almost certaindeath. Today it makes almost nodifference. Since much of the variation is due to genes, onemore agent ofevolution 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 insome religious communities, very few womenhave 15 children. Nowadays thenumber of births, like the age of death, has become average. Most of us haveroughly the same number of offspring. Again, differences between people andtheopportunity for natural selection to take advantage of it have diminished.India shows whatis happening. The country offers wealth for a few in the greatcities and poverty for theremaining tribal peoples. The grand mediocrity oftoday―everyone being the same in survivaland number of offspring meansthat natural selection has lost 80% of its power in upper-middle-class Indiacompared to the tribes。

　　For us, this means that evolution is over; the biological Utopiahas arrived. Strangely, it hasinvolved little physical change. No otherspecies fills so many places in nature. But in the past 100,000 years—even thepast 100 years—our lives have been transformed but our bodies havenot. We did notevolve, because machines and society did it for us. Darwin had a phrasetodescribe those ignorant of evolution: “they look at anorganic being as average looks at aship, as at something wholly beyond hiscomprehension。” No doubt we will remember a 20thcentury way of life beyondcomprehension for its ugliness. But however amazed ourdescendants may be athow far from Utopia we were, they will look just like us。

　　15. What used to be the danger in being a man according to thefirst paragraph?

　　[A]A lack of mates。

　　[B]A fierce competition。

　　[C]A lower survival rate。

　　[D]A defective gene。

　　16. 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 thetribes。

　　[D]India is one of the countries with a very high birth rate。

　　17. The author argues that our bodies have stopped evolving because____。

　　[A]life has been improved by technological advance