首页
登录
职称英语
Passage One (1) There’s this great recurring Saturday Night Live skit f
Passage One (1) There’s this great recurring Saturday Night Live skit f
游客
2023-11-24
49
管理
问题
Passage One
(1) There’s this great recurring Saturday Night Live skit from several years back where Phil Hartman plays an unfrozen caveman who goes to law school. He pontificates (发表武断的意见) on the American judicial system while marveling at modern technology like The Tiny People in The Magic Box (a TV). It fits a common stereotype; Human ancestors were, well, cavemen, and not as smart as we are today. A new hypothesis from a Stanford geneticist tries to turn this stereotype upside down.
(2) Human intelligence may have actually peaked before our ancient predecessors ever left Africa, Gerald Crabtree writes in two new journal articles. Genetic mutations during the past several millennia are causing a decline in overall human intellectual and emotional fitness, he says. Evolutionary pressure no longer favors intellect, so the problem is getting worse. He is careful to say that this is taking quite a long time, so it’s not like your grandparents are models of brilliance while your children will be cavemen rivaling Hartman’s SNL character. But he does maintain that an ancient Athenian, plucked from 1000 BC, would be " among the brightest and most intellectually alive of our colleagues and companions. "
(3) His central thesis is that each generation produces deleterious (有害的) mutations, so down the line of human history, our intelligence is ever more impaired compared to that of our predecessors.
(4) Not surprisingly, the hypothesis, published in the journal Trends in Genetics, has several geneticists scratching their heads.
(5) "It takes thousands of genes to build a human brain, and mutations in any one of those can impair that process, that’s absolutely true. It’s also true that with each new generation, new mutations arise...but Crabtree ignores the other side of the equation, which is selection," said Kevin Mitchell, associate professor at the Smurfit Institute of Genetics at Trinity College Dublin. "Natural selection is incredibly powerful, and it definitely has the ability to weed out new mutations that significantly impair intellectual ability. There are various aspects in these papers that I think are really just thinking about things in a wrong way. "
(6) Crabtree said he wanted to examine the cumulative effect of generation-to-generation mutation on intelligence, which is thought to be controlled by many genes. Using indexes that measure X-chromosome (染色体 )-related mental retardation, he comes up with between 2,000 and 5,000 genes related to human intellectual ability. Using another index measuring average mutations that arise in each generation of children, he calculates that within 3,000 years, "we have all sustained two or more mutations harmful to our intellectual or emotional stability. "
(7) "There is a general feeling that evolution constantly improves us, but it only does that if there is selection applied," Crabtree said in an interview. "In this case, it is questionable about how much selection is occurring now compared to the process of optimizing those genes, which occurred in the jungles of Africa 500,000 years ago. "
(8) There’s already evidence for this in other areas, he argues: Take our sense of smell. Humans have far fewer olfactory receptors than other animals, he said—we’re guided by our intellect now, not by smell. We can think about where a piece of food came from, how it was processed, which plant it’s from, who has been around it, and so on. A dog, on the other hand, simply sniffs something and either eats it or doesn’t.
(9) Similarly, he believes evolution now selects for other traits—namely, the most healthy and the most immune, not the most intelligent.
(10) But geneticists took issue with his claims, not to mention his citations and methods. Mitchell took issue with Crabtree’s characterization of genes—he describes them as links in a chain, with incredible overall disruptive power. They’re like a bulb on a string of Christmas tree lights that suddenly fails to work, taking out the entire strand with it: "It can be concluded that genes related to intelligence do not operate as a robust network, but rather as links in a chain, failure of any one of which leads to intellectual disability," he writes. Mitchell countered that this ignores other genes that don’t cause intellectual disability.
(11) "Biological systems are robust to degradation of several different components," Mitchell said. "Evolution has gone to a lot of trouble to craft your genome so it’s finely honed to do its job, and it doesn’t make sense that you would have all this random mutation in your brain cells. Also, you would have a very high rate of brain cancer. " [br] Kevin Mitchell raises doubts about Gerald Crabtree’s hypothesis in all of the following aspects EXCEPT its________.
选项
A、self-contradictory nature
B、neglect of the power of natural selection
C、research methodology and references
D、characterization of genes
答案
A
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3215246.html
相关试题推荐
PASSAGEFOUR[br]WhatdidMr.Galili’smovingfromAmsterdamtoGroningenturn
PASSAGETHREE[br]WhydidGooglebidforsomeofNortel’spatents?Toshieldits
PASSAGETWOContent.第4段中作者讲述了自己角色转换的过程以及对此的感受,从倒数第2句的awondrousbeginning(一个奇妙的开头
PASSAGEONE[br]WhatcanbeinferredfromradicalIslamicpartiesinlocalelec
PASSAGETHREE[br]WhatisAlbertHoffman’sdiscovery?Howtomakesyntheticergo
PASSAGETHREE[br]WhyisthecampaignofBeatlescarefullydesigned?Torebelag
PASSAGETWO[br]WhatwasStephen’sfeelingstowardsMaggie?Intenselove.倒数第2段第3
PASSAGEONE[br]Accordingtothelastparagraph,whatneedstobesettled?Theu
PASSAGETHREE[br]WhatmainlyaccountedfortheunemploymentinSeptember2005?
PASSAGETHREE[br]Whatdoes"atrioofcrises"(thesecondparagraph)mean?Crises
随机试题
______(据估计到2010年),thepopulationoftheworldwillhavereached7billion.Iti
______(尽管人们的兴趣不尽相同),wecanstillmakefriendswiththosewhodonothaveourho
关于土的颗粒分析试验请回答以下问题。(1)常用的颗粒分析试验方法有()。A.筛分
患儿,女,7岁。以“高热2天,皮疹1天”入院。体格检查:T38.5℃;咽痛;皮
随着年龄和才智的增长,学生的( )在他们自身品德的发展与提高上起着愈来愈重要的
目前我国的邮政运营者的法律地位属于()。A:政府部门 B:国有企业 C:股份
基于建筑信息模型(BIM)技术的施工进度计划编制流程的主要步骤有()。A.WBS
关于市场细分的说法,正确的有( )。A.市场细分的前提是顾客需求的差异性 B
甲公司适用的企业所得税率为25%,20x6年6月30日,甲公司以3000万元(
西北安装公司承建一水泥厂机电工程,合同造价2400万元,其中主材料费和非标设
最新回复
(
0
)