歷年考研英語閱讀理解2000年02

[00:03.87]2000 Passage2 [00:07.51]Being a man has always been dangerous. [00:10.94]There are about 105 males born for every 100 females, [00:17.09]but this ratio drops to near balance at the age of maturity, [00:21.84]and among 70-year-olds there are twice [00:24.16]as many women as men. [00:27.18]But the great universal of male mortality is being changed. [00:32.34]Now, boy babies survive almost as well as girls do. [00:37.40]This means that, for the first time, [00:39.91]there will be an excess of boys in those crucial years [00:43.24]when they are searching for a mate. [00:46.06]More important, another chance for natural selection [00:49.58]has been removed. [00:51.60]Fifty years ago, the chance of a baby [00:54.93](particularly a boy baby) surviving depended on its weight. [01:00.98]A kilogram too light or too heavy meant [01:04.00]almost certain death. [01:06.01]Today it makes almost no difference. [01:09.04]Since much of the variation is due to genes, [01:12.26]one more agent of evolution has gone. [01:16.49]There is another way to commit evolutionary suicide: [01:20.36]stay alive, but have fewer children. [01:24.28]Few people are as fertile as in the past. [01:27.30]Except in some religious communities, [01:30.22]very few women have 15 children. [01:33.55]Nowadays the number of births, [01:35.87]like the age of death, has become average. [01:39.80]Most of us have roughly the same number of offspring. [01:43.62]Again, differences between people [01:46.45]and the opportunity for natural selection to [01:49.17]take advantage of it have diminished. [01:51.99]India shows what is happening. [01:54.97]The country offers wealth for a few in the great cities [01:59.02]and poverty for the remaining tribal peoples. [02:02.35]The grand mediocrity of today [02:04.77]--everyone being the same in survival [02:07.20]and number of offspring [02:09.00]--means that natural selection has lost 80% of [02:12.03]its power in upper-middle-class India [02:15.16]compared to the tribes. [02:17.78]For us, this means that evolution is over; [02:21.86]the biological Utopia has arrived. [02:24.99]Strangely,it has involved little physical change. [02:29.52]No other species fills so many places in nature. [02:33.45]But in the past 100,000 years [02:36.38]--even the past 100 years [02:38.70]--our lives have been transformed [02:40.82]but our bodies have not. [02:42.92]We did not evolve, because machines [02:45.36]and society did it for us. [02:48.38]Darwin had a phrase to describe those ignorant of evolution: [02:53.01]they "look at an organic being as a savage looks at a ship, [02:57.56]as at something wholly beyond his comprehension." [03:00.90]No doubt we will remember a 20th century way of life [03:04.78]beyond comprehension for its ugliness. [03:07.71]But however amazed our descendants may be [03:10.13]at how far from Utopia we were, [03:12.75]they will look just like us.

00:00

00:00

MP3下載 文本下載