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
For hundreds of years, farmers have selected and bred plants and animals to favor, or bring out, characteristics they desired. F
For hundreds of years, farmers have selected and bred plants and animals to favor, or bring out, characteristics they desired. F
admin
2010-06-18
42
问题
For hundreds of years, farmers have selected and bred plants and animals to favor, or bring out, characteristics they desired. For example, cows that produced large amounts of milk were selected for breeding, while poor milk producers were not allowed to reproduce. In like manner, horses were bred for speed and strength. Those having these desired characteristics were selected for breeding. Over time, these preferred breeds became more common than earlier, less desired types. This selective breeding is called artificial selection.
In this passage, Camp and Arms explain how this same process occurs naturally. The theory of evolution by natural selection was put forward in a joint presentation of the views of Charles Darwin and Alfred Russell Wallace before the Linnaean Society of London in 1858. Darwin and Wallace were not the first to suggest that evolution occurred; but their names are linked with the idea of evolution because they proposed the theory of natural se- lection as the mechanism by which evolution occurs. We are always more likely to believe in a process when people explain how it happens than if they merely assert that it does.
The theory of evolution by means of natural selection is based on three observations. First, as we can see by comparing one cat or human being with another, the members of a species differ from one another; that is, there is variation among individuals of the same species. Second, some (though not all) of the differences between individuals are inherited. (Other differences are not inherited, but are caused by different environments. For in- stance, two plants with identical genes may grow to different sizes if one of them is planted in poor soil. ) Third, more organisms are born than live to grow up and reproduced many organisms die as embryos or seeds, as saplings, nestlings, or larvae.
Inherited characteristics that improve an organism’s chances of living and reproducing will be more common in the next generation and those that decrease its chances of reproducing will be less common. Various genes or combinations of genes will be naturally selected for or against, from one generation to the next, depending on how they affect reproductive potential. For natural selection to cause a change in a population from one generation to the next (that is, to cause evolution), it is not necessary that all genes affect survival and reproduction; the same result occurs if just some genes make an individual more likely to grow up and reproduce.
What do people most probably believe in about a process?
选项
A、Its definition.
B、Its explanation.
C、Its examples.
D、Its main idea.
答案
B
解析
根据第三段最后一句“We are always more likely to believe in a process when people explain how it happens than if they merely assert that it does.”,就可肯定[B]正确。
转载请注明原文地址:https://jikaoti.com/ti/Mx3YFFFM
0
专业英语八级
相关试题推荐
Goodmorning.Thediscussiontopicfortoday’sseminaris"HomelessnessinAmerica."IntheUnitedStates,homelessnesshas【C1】
Globalwarming?Youmayacceptorrejectthosewhosayitisadangerousphenomenon.Butiftheplanetiswarming,andhumanity
Globalwarming?Youmayacceptorrejectthosewhosayitisadangerousphenomenon.Butiftheplanetiswarming,andhumanity
TheHeadofSlateofCanadaisrepresentedby______.
ScientistsinBrazilhaveusedfrogskinto______.
OneofthemostinterestingparadoxesinAmericatodayisthatHarvardUniversity,theoldestinstitutionofhigherlearningin
Theformmaybesimple,andthelanguageplainasdaylight,buttheinnermeaning,thelatentcontent,ofamasterpiecewillnot
Whennatureisleftalone,abalanceisreachedamongtheanimalsandplantslivinginonearea.Butwhenmaninterfereswithna
Eversinceitappearedontheculturalscene,theEnlightenmenthashaditspassionatecritics.Philosophersaswellaspolitici
随机试题
犯罪嫌疑人与其他同案人的关系属于需要查明的案件事实。
智育
函数y=2xln—3的水平渐近线方程是()。
Thecomputerisawonderfulmachine.Itisthemostimportantinventionsincethetypeofengineusedincars.Todayithasthe
《中国药典》主要内容包括
A、冲脉B、任脉C、督脉D、带脉E、阴阳维脉具有约束纵行诸经功能的是
公开市场、货币市场和债券市场是商业银行获取资金,满足流动性需求的快捷通道。()
以市场经济的方式配置资源能产生更大的效率,主要原因在于市场通过()配置资源。
InSeptember,morethanadozenwhalesbeachedthemselvesintheCanaryIslands.Rescuerstriedtowaterdownthewhalesandkee
A、Whenapatientisatanoldage.B、Whenapatientisveryyoung.C、Whenapersondoesn’ttakefoodscontainingvitamins.D、Whe
最新回复
(
0
)