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
Most people are right-handed and children usually have the same handedness as their parents. This suggests that genes are at wor
Most people are right-handed and children usually have the same handedness as their parents. This suggests that genes are at wor
admin
2013-01-20
24
问题
Most people are right-handed and children usually have the same handedness as their parents. This suggests that genes are at work. But identical twins have identical genes, so genes cannot be the whole story. Cultural attitudes seem to have played an important part in the development of hand preferences. In the past, left-handed have suffered anything from teasing to flogging. Even today in some countries en forced right-handedness, particularly for writing and eating, is still common.
To explain the observed patterns of handedness, researchers have devised what is known as a’ geneculture coevolution’ model. The initial assumption of the model-drawn from observation of non-human primates and other mammals such as mice-is that early on in human evolution, the genetic make-up of individuals inclined them to prefer one hand or the other, but that the population was equally divided between right and left-handed people. Over time, according to the model, the interaction of genes and culture has produced a state where everyone has identical genes for handedness. This would happen if, for whatever reason, right-handers were more likely to survive and reproduce. The idea may not be that far fetched. Many biologists believe that handedness is related to brain structure, say, for example, early right-handers may have been better at language.
The model predicts that today everyone has genes which confer a basic predisposition of 78% to be right-handed. How children actually turn out, however, can be influenced by whether their parents are dextral or sinistral. For example, children may mimic their parents. Or parents may influence the handedness of their children in the way that they hand them toys or food.
The researchers reckon that a child with two right-handed parents has a 91% probability of being right-handed; a child with two left-handed parents has a probability of only 63% of being right-handed. But parental influence does not account for everything. Random events during a child’s development can also have a small effect on handedness. Even if identical twins have parents who are both dextral, factors such as their position in the womb may result in the twins not preferring the same hands.
The model seems plausible. It accurately predicts the results of 13 studies of the handedness of twins as well as the proportion of left-handers found in the population at large (roughly 12%, a figure that seems to be quite stable). Asymmetries in early tools, and in the way in which prey were clubbed, suggest that hominids as early as the Australopithecines may have preferred their right hands. Whatever the origin of this dexterous preference, though, left-handers remain at large. Some people are just sinister.
The author points out at the beginning that ______.
选项
A、handedness is solely determined by genes
B、handedness is solely determined by culture
C、handedness is determined by both genes and culture
D、handedness may be determined by factors other than genes and culture
答案
C
解析
文章的第一段开始就说了基因起着重要作用,同时又举了同卵双胞胎的例子说文化在这方面的作用,所以答案是C。
转载请注明原文地址:https://kaotiyun.com/show/4S2O777K
0
考博英语
相关试题推荐
Understandingtheculturalhabitsofanothernation,especially______containingasmanydifferentsubculturesastheUnitedStat
Therearethreeseparatesourcesofhazard【1】totheuseofnuclearreactiontosupplyuswithenergy.Firstly,theradioactivem
Therearethreeseparatesourcesofhazard【1】totheuseofnuclearreactiontosupplyuswithenergy.Firstly,theradioactivem
Hecannotseeanythingwithouthisglasses,sohemadea______ofrememberingtogetthemfixedbeforehewenttowork.
Aslongasherparentscanremember,13-year-oldKatieHarthasbeentalkingaboutgoingtocollege.Hermother,Tally,afinanc
Tenyearsagoitappearedthatnuclearpowerwouldsolvetheanticipatedenergycrisis.Althoughsuppliesofuraniumfuelwerek
(51)Beingangryincreasestheriskofinjury,especiallyamongmen,newresearchsays.Theresearchersgathereddataonmor
Topicsforcompositionshouldbe______totheexperiencesandinterestsofthestudents.
Everybodywastestime.Insteadofdoinghishomework,theschoolboywatchestelevision.Insteadofwritingheressay,thestuden
Ineconomics,demandimpliessomethingslightlydifferentfromthecommonmeaningoftheterm.Thelayman,forexample,oftenus
随机试题
下列对划线支票说法错误的是()
A.38.0~39.5℃B.37.5~39.0℃C.37.5~38.5℃D.37.5~39.5℃E.38.0~40.0℃羊的正常体温范围是
在龋病牙周病抽样调查中,为了增加样本的代表性,按什么分层是合适的
《血证论》提出的治血大法为通治血证大纲为
下列哪一项不是急性肾功能衰竭少尿期的水、电解质、酸碱平衡紊乱的临床表现
征收土地增值税和征用土地补偿的依据是()。
大气环境影响监测时,一级评价项目,监测点应包括评价范围内有代表性的环境空气保护目标,点位不少于()个。
下列实质性程序中,与查找未入账应付账款相关的有()。
(2017年真题)请围绕“有用的工具”为大班幼儿园设计主题活动,应包含三个子活动。要求:写出一个子活动的具体活动方案,包含活动的名称、目标、准备和主要环节。
Skype采用()网络拓扑。
最新回复
(
0
)