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
30
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
Advertisinghasgrowntobeanindustryworthmanybillionsofdollarsacrosstheworld.Almostallpublicspacehassomeadvert
GovernmentsAreTryingA1990UnitedNationssurveyrevealedthatthemorehighlydevelopedcountriesspendanaverageof2t
Aninternationalteamofastronomershasdiscovered11newplanetsoutsidethesolarsystem,raisingfreshspeculationaboutthe
D英国文学之作家概况。前三位作家都是19世纪英国浪漫主义的代表人,只有JamesJoyce活跃于20世纪。JamesJoyce是爱尔兰小说家,代表作有Ulysses(《尤里西斯》),APortraitoftheArtistasaYoung
MadonnafeltmorallyobligedtohelpchildrenintheAfricannationofMalawibecause
EngineersintheUnitedStatessaythey’vecreatedacheaperandmore【N1】______formof【N2】______skin,whichisalmostas【N3】__
Whichofthefollowingisnottheprincipleofspeechacttheory?
Hawthornegenerallyconcernedhimselfwithsuchissuesas______inhisfictions.
Scientistsalreadyknewthatbilingualyoungadultsandchildrenperformbetterontasksdictatedbythebrain’sexecutivecontr
WhoistheauthorofTheRivals?
随机试题
配制好的Na2S2O3应立即标定。()
细菌性阴道病不符合细菌性阴道病的是
青春期女孩的第二性征表现不包括()。
A市利达信用社系自主经营、独立核算的股份制城市集体金融企业,其理事会是经营决策权力机构,实行理事会领导下的主任负责制,主任是信用社的法定代表人,由理事会聘任并报被告中国人民银行A市分行批准。2005年l1月15日,该信用社主任冯某因受贿罪被逮捕,由副主任宋
w房地产开发公司拟在某市H乡的一处废旧厂房区建设商品房,向社会出售,该废旧厂房及土地属于H乡集体所有。根据土地使用权出让合同约定,w公司获得的这块土地只能建设住宅。W公司在对当地房地产市场形势进行了多次分析研究后,决定调整最初确定的开发方案,减少住宅用地,
在售后租回销售方式下,企业不应当确认收入和结转销售成本。()
车船使用税的纳税地点是()。
由于被告人的犯罪行为使家庭财产、集体财产遭受损失的,人民检察院在提起公诉时,可以()。
决定局域网特性的主要技术要素包括网络拓扑结构、介质访问控制方法与()。
A、Theyboughtsomeworthlesssouvenir.B、Theydidsomemanualwork.C、Theywentonacompanytrip.D、Theywroteaguidebook.C
最新回复
(
0
)