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
You do not usually get something for nothing. Now, a new study reveals that the evolution of an improved learning ability could
You do not usually get something for nothing. Now, a new study reveals that the evolution of an improved learning ability could
admin
2017-06-27
67
问题
You do not usually get something for nothing. Now, a new study reveals that the evolution of an improved learning ability could come at a particularly high price: an earlier death.
Past experiments have demonstrated that it is relatively easy through selective breeding to make rats, honey bees and—that great favourite of researchers—fruit flies a lot better at learning. Animals that are better learners should be competitive and, thus, over time, come to dominate a population by natural selection. But improved learning ability does not get selected amongst these animals in the wild. No one really understands why.
Tadeusz Kawecki and his colleagues at the University of Fribourg in Switzerland have measured the effects of improved learning on the lives of fruit flies. The flies were given two different fruits as egg-laying sites. One of these was laced with a bitter additive that could be detected only on contact. The flies were then given the same fruit but without an additive. Flies that avoided the fruit which had been bitter were deemed to have learned from their experience. Their children were reared and the experiment was run again.
After repeating the experiment for 30 generations, the children of the learned flies were compared with normal flies. The researchers report in a forthcoming edition of Evolution that although learning ability could be bred into a population of fruit flies, it shortened their lives by 15% . When the researchers compared their learned flies to colonies selectively bred to live long lives, they found even greater differences. Whereas learned flies had reduced their life spans, the long-lived flies learned less well than even average flies.
The authors suggest that evolving an improved learning ability may require a greater investment in the nervous system which takes resources away from processes that delay ageing. However. Dr. Kawecki thinks the effect could also be a by-product of greater brain activity increasing the production of Reactive Oxygen Species(ROS), which can increase oxidation in the body and damage health.
No one knows whether the phenomenon holds true for other animals. So, biologists, at least, still have a lot to learn.
In this experiment, scientists observed that______.
选项
A、some flies avoided the fruit without an addictive
B、some flies preferred the fruit with an addictive
C、the eggs of the flies were not damaged
D、the impact on the flies did not last long
答案
A
解析
推断题。从文章第三段第五句“Flies that avoided the fruitwhich had been bitter were deemed to have learned from their expe—rience.”可知,那些果蝇通过学习能力的提升能够避开带有添加剂的水果,由此可以推断,果蝇已经有经验,看见同种水果也会避开,所以果蝇也会避开没有添加剂的同种水果,故选A。
转载请注明原文地址:https://kaotiyun.com/show/6wVd777K
本试题收录于:
公共英语三级笔试题库公共英语(PETS)分类
0
公共英语三级笔试
公共英语(PETS)
相关试题推荐
Thereisevidencethattheusualvarietyofhighbloodpressureis,inpart,afamilydisease.Sincefamilieshavesimilargenes
Faces,likefingerprints,areunique.Didyoueverwonderhowitispossibleforustorecognizepeople?Evenaskilledwriterp
Sometimes,people【C1】______yourlifeandyourealizethattheyarethere【C2】______somepurpose,to【C3】______youalesson,orto
In1993,NewYorkStateorderedstorestochargeadepositonbeverage(饮料)containers.Withinayear,consumershadreturnedmi
Thecohesiveness(内聚力)ofafamilyseemstorelyonmemberssharingcertainroutinepracticesandevents.Foragrowingshareoft
Americanarchitectureisatitsbestwhenitisconcernedwithbuildingsthathaveapracticalpurpose.Factories,officebuildi
Americanarchitectureisatitsbestwhenitisconcernedwithbuildingsthathaveapracticalpurpose.Factories,officebuildi
Whatistheman’sfirsttiponaproductiveworkday?
Whatisthewomandoingatthemoment?
Whatistheman’sfirsttiponaproductiveworkday?
随机试题
阮籍《咏怀》诗忧愤深广,后人评为【】
Tobe,ornottobe—thatisthequestion;Whether’tisnoblerinthemindtosufferTheslingsandarrowsofoutrageousfortun
A地块为规划科学教育用地,宗地面积为30000平方米。经调查了解取得下列资料:该宗地所在区域征地补偿费为500元/平方米,征地管理费按规定以征地补偿费的2%计算,土地开发费为600元/平方米,税费按15元/平方米计取。土地开发周期为两年,开发资金在开发期
简述构建社会主义和谐社会的基本内容和必要性。
《建设项目环境影响评价资质管理办法》规定:评价机构有( )所列行为之一的,国家环境保护总局视情节轻重,分别给予警告、通报批评、责令限期整改3~12个月、缩减评价范围、降低资质等级或者取消评价资质。
目标分解结构与组织分解结构之间存在对应关系,因此目标分解结构()。
甲公司采用成本与可变现净值孰低计量期末存货,按单项存货计提存货跌价准备。2010年12月31日,甲公司库存自制半成品成本为35万元,预计加工完成该产品尚需发生加工费用11万元,预计产成品不含增值税的销售价格为50万元,销售费用为6万元。假定该库存自制半成品
最高管理者可根据组织的实际情况,可指定一名或几名管理者代表来行使被授权的职责,则管理者代表的主要职责是_______。
主张对儿童的教育要“诱之歌诗”、“导之以礼”、“讽之读书”的人物是
第二次国内革命战争即土地革命战争,土地革命战争的发展依赖于土地革命的进行。开展土地革命的目的是()
最新回复
(
0
)