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
2016-10-19
26
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 1.5% . 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.
We learn from the text that______.
选项
A、the research findings need to be tested further
B、biologists are doing similar research on other animals
C、the animal world usually follows the same universal laws
D、biologists are applying their findings to other areas
答案
A
解析
推断题。从文章最后一段“No one knows whether thephenomenon holds true for other animals.So,biologists,at least,still have a lot to learn.”可知,生物学家们目前只对果蝇做了实验,还不知道其他动物是否有同样效果,他们还要去继续研究,故选A。
转载请注明原文地址:https://jikaoti.com/ti/7yLsFFFM
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
Althoughfewwoulddenythatitisbettertoberichthanpoor,forsomepeoplethequestformoneyissoall-consumingthatit
Thewaypeopleholdtothebeliefthatafun-filled,painfreelifeequalshappinessactuallyreducestheirchancesofeveratta
Everyartistknowsinhisheartthatheissayingsomethingtothepublic.Notonlydoeshewanttosayitwell,buthewantsit
Thepredictabilityofourmortalityratesissomethingthathaslongpuzzledsocialscientists.Afterall,thereisnonaturalr
Thepredictabilityofourmortalityratesissomethingthathaslongpuzzledsocialscientists.Afterall,thereisnonaturalr
Beautyhasalwaysbeenregardedassomethingpraiseworthy.Almosteveryonethinksattractivepeoplearehappierandhealthier,h
Theinventionofbothlabor-savingtoolsandtoolsofintelligenceisrarelyaccidental.Instead,itisusuallytheproductofh
Thecohesiveness(内聚力)ofafamilyseemstorelyonmemberssharingcertainroutinepracticesandevents.Foragrowingshareoft
Whena13-year-oldVirginiagirlstartedsneezing,herparentsthoughtitwasmerelyacold.Butwhenthesneezescontinuedfor
随机试题
查询最近30天的记录应使用()作为准则。
(2009年4月)属于共产主义社会基本特征的有______、______、______。
已知,则f(x)=__________.
在美国有一位名叫玛丽的女佣人,她能做非常好吃的饭菜。在她15年的女佣生活中,她所工作过的许多家庭传播了伤寒50例以上。她传播病源的可能途径是
A、胃液酸度升高B、胃液酸度正常或减少C、胃液酸度常减少D、胃液酸度明显升高E、胃液酸度明显减少重度胃体萎缩型胃炎
关于单位犯罪,下列说法不正确的有是:①因最高人民法院为我国最高司法机关,所以,最高人民法院不可能成为单位犯罪的主体②在我国,单位犯罪具有法定性,对于单位实施的危害社会的行为,只有刑法明文规定为单位犯罪的,单位才负刑事责任。我国刑法没有规
请认真阅读下列材料,并按照要求作答。跨越海峡的生命桥1999年9月22日,早晨7时30分,阳光洒满了美丽的杭州市,桂树还没有开花,晨风中已经飘来甜丝丝的香气。小钱静静地躺在病床上。灿烂的阳光没有使他苍白的脸红润起来。这个刚满1
赵某涉嫌杀人,一审法院以故意杀人罪判处其无期徒刑;赵某提起上诉,二审维持原判。多年后,真凶落网。此事经媒体跟踪报道,在社会上引起强烈反响。检察机关继而提起抗诉,经再审,赵某被宣告无罪。请结合上述材料,运用法理学中法律监督的知识和原理,回答下列问题:(20
A、Inarestaurant.B、Inahotel.C、Inasupermarket.D、Inalibrary.BWherehasthewomanworkedduringhersummerholiday?
Whenateacher【B1】______astudenttoreadabookit’susuallyforaparticularpurpose.Thebookmay【B2】______usefulinformatio
最新回复
(
0
)