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
2013-03-22
75
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-handers have suffered anything from teasing to flogging. Even today in some countries enforced 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 ’gene-culture 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 farfetched. 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 par-ents. 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 Australo-pithecines may have preferred their right hands. Whatever the origin of this dextrous 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
转载请注明原文地址:https://kaotiyun.com/show/fTXd777K
本试题收录于:
公共英语五级笔试题库公共英语(PETS)分类
0
公共英语五级笔试
公共英语(PETS)
相关试题推荐
TheStoryteller1StevenSpielberghasalwayshadonegoal:totellasmanyinterestingstoriestoasmanypeopleaspossibl
A.humanisbornwithacertainpersonalityB.howthepersonalityandbehaviorareformedC.willexperienceintellectualdevel
Theworkersfinallycalledoffthestrikes.
GavinlivedinChinawhenhisfatherwasstayingin______.
Forachild,happinesshasamagicalnature.Iremembermakinghide-outsinnewly-cuthay,playingcopsandrobbersinthewoods
Forachild,happinesshasamagicalnature.Iremembermakinghide-outsinnewly-cuthay,playingcopsandrobbersinthewoods
Forachild,happinesshasamagicalnature.Iremembermakinghide-outsinnewly-cuthay,playingcopsandrobbersinthewoods
Answerquestionsbyreferringtothefollowingarticle.Whicharticle…ATheGovernmentisgoingtogivenew"jobsplitt
Accordingtothespeaker,whatareconveniencegoods?
Oursocialdevelopmentwasencouragedthroughteamwork.Weworkedingroupswithpeoplewe’dnevermet【1】.Welearnttolistent
随机试题
泡菜的________是一门学问,是制作泡菜最关键的环节。
下列叙述中,错误的是______。
桥体与龈面的关系中,不重要的是
对同一目标进行重复探测时,相邻两次探测的时间间隔,称为遥感影像的()。
某银行给钢铁厂贷款200万元,给制药厂贷款400万元,由于违约因素存在,钢铁厂最终还款额服从(100万,200万)的均匀分布,制药厂最终还款额服从(200万,400万)的均匀分布,如果钢铁厂和制药厂的违约行为相互独立,那么银行最终能从两个客户那里总共收回至
我国在量子雷达领域取得突破,获得百公里级探测威力,相对于传统雷达,探测灵敏度大幅提高。量子雷达能发现隐形飞机的基本原理是:
下列选项中,属于家庭美德要求的是()
下列关于服务器技术的描述中,错误的是()。
He’scolor-blindandcan’t______betweenredandgreeneasily.
【B1】【B4】
最新回复
(
0
)