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
Twins to Impaired Fertility of Women A woman with a twin brother has fewer children. Twin brothers can leave quite an impres
Twins to Impaired Fertility of Women A woman with a twin brother has fewer children. Twin brothers can leave quite an impres
admin
2013-01-10
55
问题
Twins to Impaired Fertility of Women
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 sharing the 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. Lu-mmaa 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。[D]项正好与事实相悖;而[A]、[B]项则是对双胞胎姐妹及双胞胎兄弟数目的比较,文中并未提及。
转载请注明原文地址:https://kaotiyun.com/show/2DhK777K
0
专业英语四级
相关试题推荐
SomecallittheSmartShooter,anewrifleforAmericaninfantrytroopsthatistwoweaponsinone,isaccurateupto1,000yar
SomecallittheSmartShooter,anewrifleforAmericaninfantrytroopsthatistwoweaponsinone,isaccurateupto1,000yar
SomecallittheSmartShooter,anewrifleforAmericaninfantrytroopsthatistwoweaponsinone,isaccurateupto1,000yar
Iflifeexpectancywereamarathon,youcouldsaythattheUnitedStatesisfadingfromthepack.Althougheveryoneislivinglo
Whywasthespeedlimitfirstreducedto55miles-per-hour?
AccordingtonewresearchreleasedthisweekfromMiller-Williams,e-commercecustomersfeelthatover80percentoftheirdecis
BasictoanyunderstandingofCanadainthe20yearsaftertheSecondWorldWaristhecountry’simpressivepopulationgrowth.F
"Mirrorworlds"isonlyoneofDavidGelernter’sbigideas.Anotheris"lifestreams"—inessence,vastelectronicdiaries."Every
BlackBerrymakerResearchinMotion(RIM)hascomebottomofalistoftheworld’sgreenestelectronicsfirms.TheCanadian-base
______,mostofwhomwerewomenandchildren.
随机试题
大肠杆菌群报告阳性的现象不包括()。
先天性并指畸形最常累及________。
治疗风寒湿痹、顽麻、痿弱无力、半身不遂等病证,可选用的灸法有
下面对于财产清查类型表述错误的是()。
我国最早使用“教育”一词的是【】
在正四棱锥P—ABC中,AB=2,点M、N分别是AB、BC的中点,求异面直线CM与PN所成的角.
Ofallthesebooks,doyouthink,whichoneis______?
艾滋病被称为“20世纪的瘟疫”,艾滋病病毒将人体内的血红蛋白作为攻击目标。()
ThepoliceofficerstoppedDavidwhenhewasdrivinghomeand______himofspeeding.
BoththeSenateandHousehealthcarebillsproposeincentivestoboostcorporatewellnessprogramsthataimtohelpemployeess
最新回复
(
0
)