1、高三英语培优外刊阅读班级：_学号：_姓名：_外刊精选人高马大的欧洲人：乳糖不耐也要喝牛奶上个月，新疆牛奶品牌麦趣尔产品抽检不合格，再次引发了关于如何选好牛奶的网络热议。实际上，很多中国人其实根本不适合喝牛奶，因为中国人乳糖不耐受的比例要远高于欧美人。而国外的一项新研究发现，原来我们印象中离不开牛奶的欧洲人，很多也是乳糖不耐受的体质。究竟为什么会有人乳糖不耐受？科学家还有哪些新发现？Early Europeans Could Not Tolerate Milk but Drank It Anyway, Study FindsIn many ways, humans are weird mamma
2、ls. And our relationship with milk is especially weird.In every mammalian species, females produce milk to feed their young. The babies digest the milk with the help of an enzyme called lactase. When the young mammals are weaned, they stop making lactase.But it is common for our species to keep cons
3、uming milk into adulthood. Whats more, about one-third of people carry genetic mutations that allow them to produce lactase throughout their lives, making it easier to digest milk. Scientists have long suspected that dairy consumption and the persistence of lactase rose together in human history. Wh
4、en people started herding cattle and other livestock some 10,000 years ago, the theory went, those with a mutation for lactase persistence gained a new source of calories and protein. But a new study suggests that the traditional story does not hold up. Researchers have found that Europeans were con
5、suming milk without lactase for thousands of years, despite the misery from gas and cramping it might have caused. Over the years, scientists have found milk on thousands of pottery fragments across Europe and neighboring regions. For the new study, the scientists used this database to create a map
6、of milk consumption over the past 9,000 years. 【词汇过关】请写出下面文单词在文章中的中文意思。1.tolerate tlret v._2.weird wd adj. _3.consume knsjum v. _4.cramp krmp v./n. _5.fragment frmnt n. _【词块学习】请从文章中找到下面中文相对应的文词块。1.借助于，利用_2.使做某事更容易_3.长期怀疑_4.理论是这样的_5.（这个故事没有）站得住脚_拓展练习阅读理解Modern medicines ability to keep us alive makes
7、 it tempting to think human evolution may have stopped. But if we look at the rate of our DNAs evolution, we can see that human evolution hasnt stopped it may even be happening faster than before.Evolution is a gradual change to the DNA of a species over many generations. It can occur by natural sel
8、ection, when certain traits created by genetic changes help an organism survive or reproduce. Such genes are thus more likely to be passed on to the next generation, so they increase in frequency in a population. Gradually, these changes and their associated traits become more common among the whole
9、 group.By looking at global studies of our DNA, we can see evidence that natural selection has recently made changes and continues to do so. Though modern healthcare disrupts a key driving force of evolution by keeping some people alive longer, in countries without access to good healthcare, populat
10、ions are continuing to evolve. Survivors of infectious disease outbreaks drive natural selection by giving their genetic resistance to offspring. Our DNA shows evidence for recent selection for resistance of killer diseases like Lassa fever and malaria. Selection in response to malaria remains in re
11、gions where the disease remains common.Humans are also adapting to their environment. Gene change allowing humans to live at high altitudes have become more common in populations in Tibet, Ethiopia, and the Andes. The spread of genetic changes in Tibet is possibly the fastest evolutionary change in
12、humans, occurring over the past 3,000 years. This rapid increase in frequency of a mutated gene that increases blood oxygen content gives locals a survival advantage in higher altitudes, resulting in more surviving children.Diet is another source for adaptations. Studies show that natural selection
13、favoring a change allowing adults to produce lactase the enzyme (酶) that breaks down milk sugars is why some groups of people can digest milk. Over 80 per cent of northwest Europeans can, but in parts of East Asia, where milk is much less commonly drunk, an inability to digest lactose is the norm. L
14、ike high altitude adaptation, selection to digest milk has evolved more than once in humans and may be the strongest kind of recent selection.Yet, despite these changes, natural selection only affects about 8 per cent of our genome. But scientists cant explain why some genes are evolving much faster
15、 than others. We measure the speed of gene evolution by comparing human DNA with that of other species. One fast-evolving gene is human accelerated region 1 (HAR1), which is needed during brain development. A random section of human DNA is on average more than 98 per cent identical to the chimp comp
16、arator, but HAR1 is so fast evolving that its only around 85 per cent similar. Though scientists can see these changes are happening and how quickly we still dont fully understand why fast evolution happens to some genes but not others.16.Which of the following statements may the author agree with?A
17、.Evolution occurs among several people overnight.B.Genes may change and some are beneficial to peoples lives.C.Evolution is done when the whole population possesses a certain gene.D.The changed genes leading to higher survival rates are chosen deliberately.17.The underlined word “disrupts” in paragr
18、aph 3 can be best replaced by_.A.explainsB.causesC.upsetsD.heals18.The author illustrates humans ongoing evolution with the following examples EXCEPT that_.A.some people can resist infectious diseases like malariaB.children in Tibet tolerate living environments with thin airC.northwestern Europeans
19、digest lactose better than East AsiansD.the human gene HAR1 resembles that of a chimp to a lesser extent19.Which of the following may serve as the title?A.What Is Natural Selection?B.Are Humans Still Evolving?C.Why Will Certain Genes Evolve?D.How Do Mutated Genes Function?外刊精选答案【词汇过关】请写出下面文单词在文章中的中文
20、意思。1.tolerate tlret v.容许，允许;忍受;容忍2.weird wd adj. 奇怪的;诡异的;怪诞的3.consume knsjum v. 消费;吃;消耗，耗费4.cramp krmp v./n. 抽筋;痛性痉挛;(腹部)绞痛5.fragment frmnt n. 碎片;片段【词块学习】请从文章中找到下面中文相对应的文词块。1.with the help of借助于，利用2.make it easier to do something使做某事更容易3.long suspected长期怀疑4.the theory goes理论是这样的5.(the story does not
21、) hold up（这个故事没有）站得住脚【全文翻译】研究显示，早期欧洲人乳糖不耐受，但仍坚持喝牛奶从很多方面来看，人类都是一种奇怪的哺乳动物，并且，我们与奶制品的关系尤为不同寻常。每一个哺乳类物种都是由雌性产出母乳来哺育后代。婴幼儿在乳糖酶的帮助下，能够消化乳汁。在它们断奶之后，体内就不再分泌乳糖酶。不过，人类通常在成年后依然保持着喝牛奶的习惯。而且，大约有三分之一的人群体内携带基因变种，让他们能继续分泌乳糖酶，也就可以更容易地消化牛奶。长期以来，科学家们一直认为，人类食用乳制品与对乳糖的耐受性是在同一历史时期出现的。该理论认为，在约1万年前，人们开始蓄养牛及其他家畜；从那时起，那些具有乳糖耐受突变基因的人们就多了牛奶这样一个新的热量和蛋白质获取来源。而一项新研究显示，这种传统说法并不能站得住脚。研究者发现，几千年来，欧洲人在体内没有乳糖酶的情况下依然在坚持喝牛奶，尽管这可能会给他们带来胀气和痉挛之苦。多年以来，科学家在来自欧洲及附近地区的数千块陶器碎片上都发现过牛奶的痕迹。在这项新研究中，他们还利用这个数据库，绘制了一幅横跨9000年的牛奶饮食地图。拓展练习阅读理解参考答案16.B17.C18.D19.B
