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
考研
Tens of thousands of years ago modern humans crossed paths with the group of hominins known as the Neandertals. Researchers now
Tens of thousands of years ago modern humans crossed paths with the group of hominins known as the Neandertals. Researchers now
admin
2016-01-02
14
问题
Tens of thousands of years ago modern humans crossed paths with the group of
hominins
known as the Neandertals. Researchers now think they also met another, less-known group called the Denisovans. The only trace that we have found, however, is a single finger bone and two teeth, but those fragments have been enough to cradle packets of Denisovan DNA across thousands of years inside a Siberian cave. Now a team of scientists has been able to reconstruct their entire genome from these deficient fragments. The analysis adds new twists to prevailing notions about ancient human history.
"Denisova is a big surprise," says John Hawks, a biological anthropologist at the University of Wisconsin-Madison who was not involved in the new research. On its own, a simple finger bone in a cave would have been assumed to belong to a human, Neandertal or other hominin. But when researchers first sequenced a small section of DNA in 2010—a section that covered about 1.9 percent of the genome—they were able to tell that the specimen was neither. "It was the first time a new group of distinct humans was discovered" via genetic analysis rather than by anatomical description, said Svante paabo. a researcher at the Max Planck Institute(M. P 1.)for Evolutionary Anthropology in Germany, in a conference call with reporters.
Now paabo and his colleagues have devised a new method of genetic analysis that allowed them to reconstruct the entire Denisovan genome with nearly all of the genome sequenced approximately 30 times over akin to what we can do for modern humans. Within this genome, researchers have found clues into not only this group of mysterious hominins, but also our own evolutionary past. Denisovans appear to have been more closely related to Neandertals than to humans, but the evidence also suggests that Denisovans and humans interbred. The new analysis also suggests new ways that early humans may have spread across the globe.
Unfortunately, the Denisovan genome doesn’t provide many more clues about what this hominin looked like than a pinky bone does. The researchers will only conclude that Denisovans likely had dark skin. They also note that there are alleles "consistent" with those known to call for brown hair and brown eyes. Other than that, they cannot say.
Yet the new genetic analysis does support the hypothesis that Neandertals and Denisovans were more closely related to one another than either was to modern humans. The analysis suggests that the modern human line diverged from what would become the Denisovan line as long as 700,000 years ago—but possibly as recently as 170,000 years ago.
According to the passage, which of the following is TRUE?
选项
A、Modern humans, Neandertals and Denisovans lived completely separated.
B、Denisovans and modern humans were more closely related.
C、Modern humans and Neandertals were more closely related.
D、There were exchanges between Denisovans and modern humans.
答案
D
解析
根据第三段第三句:Denisovans appear to have been more closely related to Nean—dertals than to humans,but the evidence also suggests that Denisovans and humans interbred可知,古人类与丹尼索瓦人杂交,可见他们之间是有交往的,因此D项为正确答案,同时,也可排除A项。另外,这句话还说明,丹尼索瓦人似乎与尼安德特人的关系比与人类的关系更加密切,故排除B项和C项。
转载请注明原文地址:https://kaotiyun.com/show/IJsZ777K
0
考研英语一
相关试题推荐
Inthatmythicalera【B1】______childrenwereseenandnotheard,anddid【B2】______theyweretoldwithout【B3】______,everyoneknew
Internetallowedpeopletopaylowerpricesforbooksbutalsoencouragedthemtopayhighpricesforsharesinlossmakingdotco
Hopemaybethelovely,lyrical,inspiringthingmanypeoplebelieveitis—"thethingwithfeathers,"asEmilyDickinsoncalled
Doesthelanguagewespeakdeterminehowhealthyandrichwewillbe?NewresearchbyKeithChenofYaleBusinessSchoolsuggest
Thepastyearortwohastestedtheideathatallpublicityisgoodpublicity,atleastwhenitcomestobusiness.Undeservedbo
InventorDeanKamentooktheflooratHarvardBusinessSchooltodiscussideas,governmentregulation,andtheplightoftheinv
"Whyarehumanssosmart?"isaquestionthatfascinatesscientists.TadeuszKawecki,anevolutionarybiologistattheUniversit
Whentheleadersoftheneweconomysaythey’renotinitforthemoney,that’snotjustbadforbusiness.It’sbadforeveryone
Whentheleadersoftheneweconomysaythey’renotinitforthemoney,that’snotjustbadforbusiness.It’sbadforeveryone
随机试题
食管癌发病可能与下列哪些因素有关
乳岩的致病因素,属()
单纯性肾病综合征多见于
某工程双代号网络计划如下图所示,其中关键线路共有()条。
招标人对已发出的招标文件进行必要的澄清或者修改的,应当在招标文件要求提交投标文件截止时间至少()前,以书面形式通知所有招标文件收受人。
隔离开关的主要作用是( )。
《工伤保险条例》的规定,职工因工作遭受事故伤害或者患职业病需要暂停工作接受工伤医疗的,停工留薪期一般不超过()。
求助者一般资料:男性,20岁,工厂工人。求助者主诉:求助者半年以前与同一工厂的女工确立了恋爱关系,他很爱女友,只要是女友说的话他都会相信,女友要什么都会毫不犹豫地买给女友。一个月以前他发现女友和其他人有暖昧关系,很震惊,求助者认为自己对女友那么好
中国作家莫言获得2012年度诺贝尔文学奖,引发了世界文坛乃至国际社会的普遍关注,有的评价他_______,有的质疑他的获奖资格。然而,此前的获奖者大多在他国_______,获“诺奖”后方才引发国际关注;相比之下,莫言是早已被海内外所熟知的中国作家,他在世界
请阅读下面的摘要,概括摘要中描述研究方法的部分,并说明该研究是否有可以改进的地方。提取干扰对内隐记忆的影响摘要:以往研究多认同内隐记忆不会受到干扰的影响,但主要集中于编程时的干扰不会影响随后的内隐记忆的提取成绩,而对于提取时的干扰是否也不会影响内隐记忆
最新回复
(
0
)