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
2015-10-20
31
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 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 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—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/fkzZ777K
0
考研英语一
相关试题推荐
Itistheworld’sfourth-most-importantfoodcrop,aftermaize,wheatandrice.Itprovidesmorecalories,morequickly,usingl
Shemanagedtosave______shecouldoutofherwagestohelpherbrother.
Youaresupposedtoputforwardsomerulesforjob-seekersandyoumayofferyoursuggestionsintermsofthefollowingpoints:
Sportpsychologyresearchhasdocumentedtheimportantroteofsignificantadultssuchasparentsandcoachesinyouthparticipa
Brothersandsistersfight,butwhenthebickeringevolvesintophysicaloremotionalabuse,it’sbullying.Ordinaryargumentso
Brothersandsistersfight,butwhenthebickeringevolvesintophysicaloremotionalabuse,it’sbullying.Ordinaryargumentso
Awomanwithatwinbrotherhasfewerchildren.Twinbrotherscanleavequiteanimpression.Themerepresenceofaboyinthes
Awomanwithatwinbrotherhasfewerchildren.Twinbrotherscanleavequiteanimpression.Themerepresenceofaboyinthes
随机试题
_______是现代学校教学的基本组织形式。
异烟肼的抗菌作用特点是
质量策划的关键是()。
李某出差归来报销差旅费,出具的报销凭证有飞机票、公交车票等各种发票共计11张,填制了报销清单且经领导签字审批后,出纳员当即给予报销。会计人员在根据该项业务编制记账凭证时,记账凭证的附件数量应填11。()
辽菜的代表菜有()。
黑龙江省地形地貌的主要特征是山地、河流、()交叉分布。
Inmodernsocietythereisagreatdealofargumentaboutcompetition.Somevalueithighly,believingthatitisresponsiblefo
你能找出最后那个数字盘中问号部分应当填入的数字吗?
与组织在进行单项目管理时所采用的项目管理方法不同,多项目管理有其自身的特点。关于多项目管理环境下的资源平衡技术的理解,()是正确的。
Atthemomentsheis_________thevolleyballmatchbetweentheJapaneseteamandtheChineseteamoverattheplayingfield.
最新回复
(
0
)