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
考研
A woman with a twin brother has fewer children. Twin brothers can leave quite an impression. The mere presence of a boy in the s
A woman with a twin brother has fewer children. Twin brothers can leave quite an impression. The mere presence of a boy in the s
admin
2019-08-01
39
问题
A woman with a twin brother has fewer children. Twin brothers can leave quite an impression. The mere presence of a boy in the same womb as his sister causes her to develop bigger teeth than she otherwise would. Girls with twin brothers perform better on spatial-ability tests. They have better ball skills than most females and are more likely to be short-sighted. Now it seems that sharingthe womb also has a harmful effect on the sexual reproduction of women with a twin brother.
Virpi Lummaa of the University of Sheffield, in Britain, and her colleagues made the claim after studying detailed data from several generations of church records from many parishes in Finland. They report that women with a twin brother were 15% less likely to get married than were women with a twin sister. Those with a male twin also had a 25% lower chance of giving birth even though they lived just as long as those with a female twin. When the researchers considered only married women, those with a twin brother on average had two fewer children during their lifetimes than did women with a twin sister. And finally—to rule out any influence of sharing a house as well as a womb—Dr Lummaa checked the results were the same for women whose twin brothers died before they were three months old. The researchers reported their findings in this week’s Proceedings of the National Academy of Sciences.
As with the teeth, the supposed cause of untypical female biology is early exposure to testosterone. This hormone is made by a male fetus’s developing testes from about seven weeks after conception and is thought to diffuse, thus influencing his sister’s growth. But the exact mechanism by which a twin brother lowers his sister’s chances of reproductive success is unclear.
Dr Lummaa’s results also suggest that, if a woman wishes to maximize the chances of passing on her genes, she would do better to avoid producing pairs of twins consisting of one boy and one girl and go for a single-sex combination instead. Mothers included in the study who produced opposite-sex twins had 19% fewer grandchildren than did mothers who gave birth to same-sex twins.
Evolutionary theory thus predicts that there should be fewer pairs of girl-and-boy non-identical twins than single-sex pairs of non-identical twins. Whether that is so requires another set of figures. Finnish church records, helpful as they are, do not distinguish non-identical same-sex twins from identical ones. In the eyes of God, unlike those of natural selection, twin girls are created equal.
The word "conception" (Para. 3) has a meaning closest to _____.
选项
A、childbirth
B、pregnancy
C、teeth-forming
D、organs’ forming
答案
B
解析
语义理解题。该段指出龙凤胎中的女性生育几率降低的原因可能与她们过早接触到了睾丸激素有关,而睾丸激素是由conception七周后a male fetus’s developing testes产生的,虽然很多考生对fetus和testes这两个单词不熟悉,但是developing一词传递出“正在形成中”的意思,结合前面提到的“过早接触”,可以推得pregnancy(受孕)最为恰当,故选B项。
转载请注明原文地址:https://kaotiyun.com/show/s12Z777K
0
考研英语一
相关试题推荐
Americanpresidentsseemtoagebeforeoureyes.Butthecommonbeliefthathigh-officestressgraysourleadersfasterthan【C1】
Americanpresidentsseemtoagebeforeoureyes.Butthecommonbeliefthathigh-officestressgraysourleadersfasterthan【C1】
Americanpresidentsseemtoagebeforeoureyes.Butthecommonbeliefthathigh-officestressgraysourleadersfasterthan【C1】
Americanpresidentsseemtoagebeforeoureyes.Butthecommonbeliefthathigh-officestressgraysourleadersfasterthan【C1】
Thedigitalattackfrome-booksandAmazon-styleonlineretailershaveputbookstoresinanexistentialdilemma.Digitalbooksa
ThebusinesspracticesofAmericawillhaveyouintheofficefromnineinthemorningtofiveintheevening,ifnotlonger.Mu
Theshortergrowingseasonsexpectedwithclimatechangeoverthenext40yearswillendangerhundredsofmillionsofalreadypo
Theshortergrowingseasonsexpectedwithclimatechangeoverthenext40yearswillendangerhundredsofmillionsofalreadypo
WhilewesterngovernmentsworryoverthethreatofEbola,amorepervasivebutfarlessharmful【C1】______isspreadingthroughth
Forthefirsttime,GeorgeBushhasacknowledgedtheexistenceofsecretCIAprisonsaroundtheworld,wherekeyterroristsuspe
随机试题
向无规定动物疫病区运输相关易感动物、动物产品,(),即分别由输出地动物卫生监督机构和输入地省级动物卫生监督机构检疫合格后,方可进人无规定动物疫病区
A.中性粒细胞增多B.淋巴细胞增多C.单核细胞增多D.嗜酸粒细胞增多E.嗜碱粒细胞增多
患者,女,28岁,平素月经规律,28~30天一次,每次持续3~4天,其末次月经是2月11日,距今已有8周,现患者感觉乏力,乳房触痛明显。实验室检查提示尿妊娠反应(+),此检查是查的体内的()
重力式挡土墙的组成有()。
现代社会中,人们是在相对统一的时间里交往活动,这有利于节约社会成本,提高社会效率,推动社会发展。但全社会的“步调一致”容易导致交通的堵塞,由此引发的一系列社会问题不容忽视。从另一方面来看,人们的需要、社会发展的需求,又对作息时间提出了不同的要求。但作息时间
甲、乙、丙三人各自独立地去破译一个密码,则密码能被破译的概率为.()(1)甲、乙、丙三人能译出密码的概率分别为.(2)甲、乙、丙三人能译出密码的概率分别为.
1958年5月,中共八大二次会议通过了“鼓足干劲、力争上游、多快好省地建设社会主义”社会主义建设总路线
在关系模式R(u)中,如果X->Y,并且对于X的任何一个真子集X’,都有X’->Y,则称
有以下程序:#include<stdio.h>#definePT3.5:#defineS(x)PT*x*x;main(){inta=1,b=2;prinff("%4.1f\n",S(a+b));}程序的运行结果是()。
从20世纪下半叶起,英语作为全球通用语盲的地位进一步得到巩固和发展。英语已经不再是非英语国家和英语国家的人们进行交流时的工具,而更多地成为非英语国家之间的人们进行沟通的共用语言。英语在非英语国家的发展已经造成了许多带有浓厚地域特色的变体,它们的诞生已经或将
最新回复
(
0
)