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
39
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.
According to Dr. Kawecki, greater brain activity______.
选项
A、reduces oxygen consumption
B、regulates the nervous system
C、speeds up the ageing process
D、stabilizes the ageing process
答案
C
解析
推断题。从文章第五段最后一句“However,Dr.Kaweckithinks the effect could also be a by—product of greater brain activityincreasing the production of Reactive Oxygen Species(ROS),which can increase oxidation in the body and damage health.”可知,奎克教授认为这种影响也可能是大脑活动产生活性氧的副作用,活性氧会增强身体的氧化并损害健康。由此可推断,大量的脑力活动会加速衰老,故选C。
转载请注明原文地址:https://kaotiyun.com/show/IwVd777K
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?
Sometimes,people【C1】______yourlifeandyourealizethattheyarethere【C2】______somepurpose,to【C3】______youalesson,orto
Themessageof【C1】______suchasthisis【C2】______naturalsystemsarecomplex,unpredictable:understandingthem【C3】______patien
HowdoesthemanusuallyspendThanksgiving?
Manyteachersbelievethattheresponsibilitiesforlearningliewiththestudent.【C1】______alongreadingassignmentisgiven,
Onesummernight,onmywayhomefromworkIdecidedtoseeamovie.Iknowthetheaterwouldbeair-conditionedandIcouldn’t
Whena13-year-oldVirginiagirlstartedsneezing,herparentsthoughtitwasmerelyacold.Butwhenthesneezescontinuedfor
Whena13-year-oldVirginiagirlstartedsneezing,herparentsthoughtitwasmerelyacold.Butwhenthesneezescontinuedfor
Whatistheman’sfirsttiponaproductiveworkday?
随机试题
己知函数f(x)在[0,1]上可导,f(x)>0,f(0)=1,且在[0,1)满足等式求函数f(x).
以下关于口服降糖药叙述错误的是
治疗米面薯芋等淀粉性食滞证,宜首选
某县政府为了加强社会治安综合治理,从事业单位抽调李某等五人组成治安巡逻大队。县公安局为他们发放了工作证,配备了手铐等警械,并规定其职责是负责维持县城集市贸易区的治安。一日,李某等人巡逻至城西区农贸市场时,发现张某等人在打架斗殴、寻衅滋事。遂作出对张某处1
逻辑函数F=的简化结果是()。
对一个文件来说,必须有()。
下列项目中,按税法规定可以免征或不征土地增值税的有()。
通过观察儿童在日常生活、游戏、学习和劳动等活动中的表现,以研究儿童心理的特点和规律,这种研究方法是()。
Employee的表结构为:职工号、单位号、工资,查询单位号为"002"的所有记录存储于临时表文件info中,正确的SQL命令是
在中国,食物是用大的公用盘子(communalplate)来盛装的,而且基本上都会提供公用的筷子来将食物从公用的盘子里弄到你自己的盘子里。如果有公用的筷子就用公共的筷子来分开食物。如果没有,或是不确定有没有,你可以先等一等,看其他人是怎么做的,然后效仿就
最新回复
(
0
)