首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Being a man has always been dangerous. There are about 105 males born for every 100 females , but this ratio drops to near balan
Being a man has always been dangerous. There are about 105 males born for every 100 females , but this ratio drops to near balan
admin
2011-05-16
93
问题
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, boy 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 change. 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 a savage looks at a ship, as at some-thing 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.
What does the example of India illustrate?
选项
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.
答案
B
解析
本文第二段最后两句话表示这个国家给大城市的一部分人提供了财富,而其余的部落民族却一贫如洗。今天众多的普通人,每个人在存活子女的数量方面都一样,这意味着:与部落相比,自然选择在印度的中上阶层已失去了80%的效应。这与B中的“自然选择在富人与穷人中已很难起作用”的意思相吻合,故应选B。A富人生的孩子没有穷人生得多,与上面的表述相矛盾。C中等阶层的人口比部落人口少80%和D印度是个高出生率的国家,文中都未提及。
转载请注明原文地址:https://kaotiyun.com/show/axxd777K
本试题收录于:
公共英语四级笔试题库公共英语(PETS)分类
0
公共英语四级笔试
公共英语(PETS)
相关试题推荐
Scholarsandstudentshavealwaysbeengreattravellers.Theofficialcasefor"academicmobility"isnowoftenstatedinimpres
(61)Beautyhasalwaysbeenregardedassomethingpraiseworthy.Almosteveryonethinksattractivepeoplearehappierandhealthi
(61)Beautyhasalwaysbeenregardedassomethingpraiseworthy.Almosteveryonethinksattractivepeoplearehappierandhealthi
(61)Beautyhasalwaysbeenregardedassomethingpraiseworthy.Almosteveryonethinksattractivepeoplearehappierandhealthi
Manyayoungpersontellsmehewantstobeawriter.Ialwaysencouragesuchpeople,butIalsoexplainthatthere’sabigdiff
Manyayoungpersontellsmehewantstobeawriter.Ialwaysencouragesuchpeople,butIalsoexplainthatthere’sabigdiff
随机试题
将下列乐谱移高纯四度记谱。
女性,56岁,高血压、糖尿病史3年,突发胸前区疼痛3小时入院。心电图标准12导联是Ⅱ、Ⅲ及aVFST段抬高,病理性Q波,血压85/60mmHg,心率110次/分,心脏三尖瓣区可闻及SM2~3/6反流样杂音,双肺呼吸音清,颈静脉怒张,肝肋下1cm。该例目前
糖原累积病1型患儿纠正酸中毒时禁用
A.失调症、帕金森综合征和不随意运动B.失语、失用和失认C.血压和体温调节障碍D.瘫痪初期出现肌张力下降,反射消失,不能维持自主活动的弛缓状态E.首先恢复的最简单的反射如腱反射变为亢进中枢神经损伤后初期的休克状态是
三棱针针刺方法不包括
下列关于桩的承载力的叙述,其中不恰当的一项是:
专业监理工程师应及时建立()完成工程量和工作量统计表。
宣告一次审核的结束的标志是_________。
王霸字元伯,颍川颍阳人也。汉兵起,光武过颍阳,遂从击破王寻、王邑于昆阳。及光武为大司马,以霸为功曹令史,从度河北。宾客从霸者数十人,稍稍引去。光武谓霸曰:“颍川从我者皆逝,而子独留。努力!疾风知劲草。”及王郎起,光武在蓟,郎移檄购光武。光武即南驰至下曲阳。
设向量β可由向量组α1,α2,…,αm线性表出,但不能由向量组(I):α1,α2,…,αm-1线性表出.记向量组(Ⅱ):α1,α2,…,αm-1,β,则().
最新回复
(
0
)