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
One of the paradoxes of human biology is that the rich world has fewer children than the poor world. In most species, improved c
One of the paradoxes of human biology is that the rich world has fewer children than the poor world. In most species, improved c
admin
2015-10-21
67
问题
One of the paradoxes of human biology is that the rich world has fewer children than the poor world. In most species, improved circumstances are expected to increase reproductive effort, not reduce it, yet as economic development gets going, country after country has experienced what is known as the demographic transition; fertility(defined as the number of children borne by a woman over her lifetime)drops from around eight to near one and a half. That number is so small that even with the reduced child mortality which usually accompanies development it cannot possibly sustain the population.
This reproductive collapse is particularly worrying because it comes in combination with an increase in life expectancy which suggests that, by the middle of the century, not only will populations in the most developed countries have shrunk(unless they are propped up by historically huge levels of immigration)but also that the number of retired individuals supported by each person of working age will increase significantly. If Mikko Myrskyla of the University of Pennsylvania and his colleagues are correct, though, things might not be quite as bad as that. A study they have just published in Nature suggests that as development continues, the demographic transition goes into reverse.
Dr. Myrskyla compared two things. One was the total fertility rate(the number of children that would be born to a woman in a particular country over the course of her life if she experienced the age-specific fertility rates observed in that country during the calendar year in question). The other was the human development index for that country. The HDI, a measure used by the United Nations, has three components: life expectancy; average income per person; and level of education. Its maximum possible value is one.
Back in the 1970s, no country got anywhere near one. Of the 107 places the researchers looked at, the best was Canada, with an HDI of 0.89. By 2005, however, things had improved markedly. Two dozen of what were now 240 countries had HDIs above nine—and something else remarkable had happened. Back in 1975, a graph plotting fertility rate against the HDI fell as the HDI rose. By 2005, though, the line had a kink in it. Above an HDI of 0. 9 or so, it turned up, producing what is known in the jargon as a "J-shaped" curve(even though it is the mirror image of a letter J). In many countries with really high levels of development(around 0.95)fertility rates are now approaching two children per woman. There are exceptions, notably Canada and Japan, but the trend is clear.
Why this change has come about, and why the demographic transition happens in the first place, are matters of debate. There are lots of social explanations of why fertility rates fall as countries become richer. The increasing ability of women in the developed world to control their own reproductive output is one, as is the related phenomenon of women entering the workplace in large numbers. The increasing cost of raising children in a society with more material abundance plays a part. So does the substitution of nationalised social-security systems for the support of offspring in old age. Falling rates of child mortality are also significant. Conversely, Dr. Myrskyla speculates that the introduction of female-friendly employment policies in the most developed countries allows women to have the best of both worlds, and that this may contribute to the uptick.
No doubt all these social explanations are true as far as they go, but they do not address the deeper question of why people’s psychology should have evolved in a way that makes them want fewer children when they can afford more. There is a possible biological explanation, though.
What does the word " uptick" at the end of the 5th paragraph refer to?
选项
A、Longer life expectancy.
B、Rising survivability of children.
C、More and more women pursuing their own career.
D、Increasing fertility rates in countries with HDI above 0.9.
答案
D
解析
语义题。第五段解释了发生“人口转变”(即国家越发达生育率越低)的原因,该段最后一句的“Conversely”显示此处行文发生转折,转而解释另一个现象,即第四段介绍的“J形”分布:一些国家在发展到当HDI超过0.9时,生育率不降反升。按照迈斯基拉博士的观点,一些最发达国家实施了有利于妇女的就业政策,使得妇女可以多生孩子而无后顾之忧。因此选[D]。
转载请注明原文地址:https://kaotiyun.com/show/FFKO777K
0
专业英语八级
相关试题推荐
WhichisthelargestfreshwaterlakeintheUnitedStates?
Decisionscanbemadequickly,ortheycanbemadeaftercarefulthought.Doyouagreeordisagreewiththefollowingstatement?
EffectiveNote-takingThedifficultyoftakingnotes:Note-takingrequiresahighlevelofabilityduetothe【B1】______ofsp
EffectiveNote-takingThedifficultyoftakingnotes:Note-takingrequiresahighlevelofabilityduetothe【B1】______ofsp
Hawaii’s【N1】______isgivingschoolchildrensomereasontosmile.PublicschoolsaregonnabeclosedmostFridaysforthe【N2】__
MadonnafeltmorallyobligedtohelpchildrenintheAfricannationofMalawibecause
ScientistsinBrazilhaveusedfrogskinto
HowtoUsetheLibraryThebooksinalibrarycanbeclassifiedundertwomain【1】—fictionandnonfiction.Whendoingresearch
Experimentsonmonkeyswereviewedmuchmorenegativelythanthoseinvolvingmouse.Indeed,onlyexperimentstodevelop【M1】_____
Experimentsonmonkeyswereviewedmuchmorenegativelythanthoseinvolvingmouse.Indeed,onlyexperimentstodevelop【M1】_____
随机试题
女性,35岁,产后哺乳期,右乳红肿,1周来已扩展至全乳,体温36.8℃。右乳皮肤红肿、边界不清、乳房发硬、无压痛,未触到肿物,无波动感,右腋下触及直径约1cm大小的肿大淋巴结,尚活动、无压痛。(2007年)该病人明确诊断后,应采取的最恰当治疗是
卡那霉素的主要不良反应:氨苄西林的主要不良反应:
A.鸡内金B.山楂C.神曲D.莱菔子E.麦芽善消肉食积滞的药物是
早产儿,男,出生第4天,因体温下降、拒乳10小时入院。查体:体温35℃,皮肤呈暗红色、凉、双小腿皮肤又硬又肿。该患儿最可能发生了
某项目当折现率i1=12%时,财务净现值FNPV1=2800万元,当i2=13%时,FNPV2=-268万元,用试差法计算财务内部收益率为()%。
背景资料 某地新建—水库,其库容为3亿m3,土石坝坝高75m。批准项目概算中的土坝工程概算为1亿元。土坝工程施工招标工作实际完成情况如下表:根据《水利水电土建工程施工合同条件》(GF-2000-0208),发包人与投标人A签订了施工合同。其中
下列关于消防控制室值班要求的表述,错误的是()。
在订单匹配原则方面,各国证券交易所普遍使用()原则作为第一优先原则。
关于法治国家,下列论述正确的有()。
游客乘电梯从底层到顶层观光,电梯于每个整点的5分、25分、55分从底层上行,设一游客早上8点X分到达底层,且X在[0,60]上服从均匀分布,求游客等待时间的数学期望.
最新回复
(
0
)