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
94
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.
According to the last paragraph, in the future, there are probably more _____.
选项
A、twin sisters than twin brothers
B、twin brothers than twin sisters
C、single-sex twins than boy-and-girl twins
D、boy-and-girl twins than single-sex twins
答案
C
解析
推理判断题。定位在最后一段。该段提到进化理论预测,与同性异卵双胞胎相比,异性异卵双胞胎应该会越来越少,可以合理推断同性双胞胎应该会比异性双胞胎数量多,故选C项。
转载请注明原文地址:https://kaotiyun.com/show/722Z777K
0
考研英语一
相关试题推荐
Americanpresidentsseemtoagebeforeoureyes.Butthecommonbeliefthathigh-officestressgraysourleadersfasterthan【C1】
Americanpresidentsseemtoagebeforeoureyes.Butthecommonbeliefthathigh-officestressgraysourleadersfasterthan【C1】
Thedigitalattackfrome-booksandAmazon-styleonlineretailershaveputbookstoresinanexistentialdilemma.Digitalbooksa
Theshortergrowingseasonsexpectedwithclimatechangeoverthenext40yearswillendangerhundredsofmillionsofalreadypo
Theshortergrowingseasonsexpectedwithclimatechangeoverthenext40yearswillendangerhundredsofmillionsofalreadypo
Themajortaskfacingadolescentsistocreateastableidentity.Therearesomedevelopmentaltasksthatenablethemtocreate
Themajortaskfacingadolescentsistocreateastableidentity.Therearesomedevelopmentaltasksthatenablethemtocreate
Sugarposesenoughhealthrisksthatitshouldbeconsideredacontrolledsubstancejustlikealcoholandtobacco,argueateam
Themorepeoplehearhisdementedrants,themoretheyseethatheisaterrorist______.
Horribletoilets.Stagnantpuddlesbuzzingwithdengue-spreadingmosquitoes.Collapsingmasonry.Laxsecurity.Aterroristattac
随机试题
对于石方开挖工程,机械与设备组合的最好选择是()。
从所给的四个选项中,选择最合适的一个填入问号处,使之呈现一定的规律性()。
(2004年第146题)下列选项中,属于B细胞淋巴瘤的有
四格表资料卡方检验的检验假设是
A.止咳B.止汗C.止泻D.止血E.止遗
A.心阴不足B.心阳不足C.心肾阳虚D.气虚血瘀E.水气凌心射肺风湿性心脏瓣膜病患者,症见:心悸喘促,不能平卧,四肢水肿,形寒肢冷,便溏尿少,舌淡苔白,脉沉细弱。其证型是
如建筑物的高度相同,则其平面形式为()时体型系数最小,随着体型系数的增加,单位面积的传热量也相应加大。
已知2010年A公司甲产品的市场销售额为2400万元,A公司的最大竞争对手是B公司。B公司的市场销售额为2100万元,甲产品近年的平均市场增长率为15%。假设市场增长率和相对市场占有率分别以10%和100%作为高低的界限标准。要求:对A公司的甲产品进行
区域的发展一般可以分为三个阶段:初期阶段、成长阶段和衰落阶段。结合下图,完成下列问题。在区域发展的初期阶段,下列关于区域内的产业结构及产业特征的说法,正确的是()。
龙涎香龙涎香是一种名贵的动物香料,有“天香”“香料之王”等美誉。它与麝香的香韵一样,几乎是所有高级香水和化妆品中必不可少的配料。龙涎香的香味清灵而温雅,既含有麝香气息,又微带壤香、海藻香、木香和苔香,有着一种特别的甜气和莫可名状的奇异香气。其留香
最新回复
(
0
)