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
85
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
Whatwillthewomanprobablydo?
Thereisevidencethattheusualvarietyofhighbloodpressureis,inpart,afamilydisease.Sincefamilieshavesimilargenes
ThenumberofspeakersofEnglishinShakespeare’stimeisestimatedtohavebeenaboutfivemillion.Todayitisestimatedthat
Sometimes,people【C1】______yourlifeandyourealizethattheyarethere【C2】______somepurpose,to【C3】______youalesson,orto
Themessageof【C1】______suchasthisis【C2】______naturalsystemsarecomplex,unpredictable:understandingthem【C3】______patien
Manyteachersbelievethattheresponsibilitiesforlearningliewiththestudent.【C1】______alongreadingassignmentisgiven,
Onesummernight,onmywayhomefromworkIdecidedtoseeamovie.Iknowthetheaterwouldbeair-conditionedandIcouldn’t
Americanarchitectureisatitsbestwhenitisconcernedwithbuildingsthathaveapracticalpurpose.Factories,officebuildi
Whatisthewomandoingatthemoment?
Whatistheman’sfirsttiponaproductiveworkday?
随机试题
在加工细长轴工件时,如果工序只进行到一半,工件在机床上,可在中间部位用木块支承起来。()
设3元非齐次线性方程组Ax=b的增广矩阵(A,b)经初等行变换可化为(A,b)→若该方程组无解,则数k=__________.
患者王某,女,46岁,以子宫肌瘤住院准备手术。检验结果显示,HBsAg阳性,张晓护士在给患者采血时被针头扎伤,扎伤处出血不止。张晓护士应采取怎样的紧急措施处理伤口?
材料一:法律是治国之重器,法治是国家治理体系和治理能力的重要依托。全面推进依法治国,是解决党和国家事业发展面临的一系列重大问题,解放和增强社会活力、促进社会公平正义、维护社会和谐稳定、确保党和国家长治久安的根本要求。要推动我国经济社会持续健康发展,不断开拓
分部工程所属的分项工程的合格率不低于95%且其他要求也满足规定时,该分部工程方可评定为合格。()
目前我国编制CPI时包括的商品和服务项目(如食品、衣着等)共有()。
在结构化方法中,软件功能分解属于下列软件开发中的阶段是()。
•Youwillhearthreetelephoneconversationsormessages.•Writeoneorwowordsoranumberinthenumberedspacesonthenot
Accordingtomyobservation,thosewhoarehappyinlifealwayshaveastrongwill.
A、Two.B、Three.C、One.D、Four.A
最新回复
(
0
)