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
"Migration from Asia" The Asian migration hypothesis is today supported by most of the scientific evidence. The first "hard"
"Migration from Asia" The Asian migration hypothesis is today supported by most of the scientific evidence. The first "hard"
admin
2018-07-24
75
问题
"Migration from Asia"
The Asian migration hypothesis is today supported by most of the scientific evidence. The first "hard" data linking American Indians with Asians appeared in the 1980s with the finding that Indians and northeast Asians share a common and distinctive pattern in the arrangement of the teeth. But perhaps the most compelling support for the hypothesis comes from genetic research. Studies comparing the DNA variation of populations around the world consistently demonstrate the close genetic relationship of the two populations, and recently geneticists studying a virus sequestered in the kidneys of all humans found that the strain of virus carried by Navajos and Japanese is nearly identical, while that carried by Europeans and Africans is quite different.
The migration could have begun over a land bridge connecting the continents. During the last Ice Age 70,000 to 10,000 years ago, huge glaciers locked up massive volumes of water and sea levels were as much as 300 feet lower than today. Asia and North America were joined by a huge subcontinent of ice-free, treeless grassland, 750 miles wide. Geologists have named this area Beringia, from the Bering Straits. Summers there were warm, winters were cold, dry and almost snow-free. This was a perfect environment for large mammals—mammoth and mastodon, bison, horse, reindeer, camel, and saiga (a goatlike antelope). Small bands of Stone Age hunter-gatherers were attracted by these animal populations, which provided them not only with food but with hides for clothing and shelter, dung for fuel, and bones for tools and weapons. Accompanied by a husky-like species of dog, hunting bands gradually moved as far east as the Yukon River basin of northern Canada, where field excavations have uncovered the fossilized jawbones of several dogs and bone tools estimated to be about 27,000 years old.
Other evidence suggests that the migration from Asia began about 30,000 years ago—around the same time that Japan and Scandinavia were being settled. This evidence is based on blood type. The vast majority of modern Native Americans have type O blood and a few have type A, but almost none have type B. Because modern Asian populations include all three blood types, however, the migrations must have begun before the evolution of type B, which geneticists believe occurred about 30,000 years ago.
By 25,000 years ago human communities were established in western Beringia, which is present-day Alaska. A But access to the south was blocked by a huge glacial sheet covering much of what is today Canada. How did the hunters get over those 2,000 miles of deep ice? The argument is that the climate began to warm with the passing of the Ice Age, and about 13,000 b.c.e. glacial melting created an ice-free corridor along the eastern front range of the Rocky Mountains. B Soon hunters of big game had reached the Great Plains.
In the past several years, however, new archaeological finds along the Pacific coast of North and South America have thrown this theory into question. C The most spectacular find, at Monte Verde in southern Chile, produced striking evidence of tool making, house building, rock painting, and human footprints conservatively dated long before the highway had been cleared of ice. D Many archaeologists now believe that migrants moved south in boats along a coastal route rather than overland. These people were probably gatherers and fishers rather than hunters of big game.
There were two later migrations into North America. About 5000 b.c.e. the Athapascan or Na-Dene people began to settle the forests in the northwestern area of the continent. Eventually Athapascan speakers, the ancestors of the Navajos and Apaches, migrated across the Great Plains to the Southwest.
The final migration began about 3000 B.C.E after Beringa had been sub merged, when a maritime hunting people crossed the Bering Straits in small boats. The Inuits (also known as the Eskimos) colonized the polar coasts of the Arctic, the Yupiks the coast of southwestern Alaska, and the Aleuts the Aleutian Islands.
While scientists debate the timing and mapping of these migrations, many Indian people hold to oral traditions that include a long journey from a distant place of origin to a new homeland.
Which of the sentences below best expresses the information in the highlighted statement in the passage? The other choices change the meaning or leave out important information.
选项
A、Beringia was under water when the last people crossed the straits in boats about 3000 B.C.E.
B、Beringia sank after the last people had crossed the straits in their boats about 3000 B.C.E.
C、About 3000 b.c.e., the final migration of people in small boats across Beringia had ended.
D、About 3000 b.c.e., Beringia was flooded, preventing the last people from migrating in small boats.
答案
A
解析
Beringia was under water paraphrases "Beringia had been submerged" and the last people paraphrases "The final migration."
转载请注明原文地址:https://kaotiyun.com/show/V3fO777K
0
托福(TOEFL)
相关试题推荐
Labeltheplanbelow.Writethecorrectletter,A-l,nexttoquestions16-20Whereinthemuseumarethefollowingplaces?Gal
Labelthemapbelow.Writethecorrectletter,A-H,nexttoquestions15-20.Museum______
Completethesentencesbelow.WriteNOMORETHANTWOWORDSforeachanswer.Thedreamtimecanbeexperiencedbeneaththe______
ChooseTWOletters,A-E.WhichTWOrecentdevelopmentsinroof-gardenbuildingarementioned?AwaterproofbarriermaterialsBd
Completethenotesbelow.WriteONEWORDONLYforeachanswer.DevelopmentStudiesDevelopmentStudiesattemptstounderstand-
"MigrationfromAsia"TheAsianmigrationhypothesisistodaysupportedbymostofthescientificevidence.Thefirst"hard"
PatentsandInventionsWhenaninventionismade,theinventorhasthreepossiblecoursesofactionopentohim:first,hec
PatentsandInventionsWhenaninventionismade,theinventorhasthreepossiblecoursesofactionopentohim:first,hec
"ConquestbyPatents"→Patentsareaformofintellectualpropertyrightsoftentoutedasameanstogive’incentiveandrew
随机试题
慢性非特异性唇炎的临床表现为
白先生,60岁,因脑出血急诊人院。血压180/120mmHg,心率60次/min,意识不清,大小便失禁,右侧肢体偏瘫。根据医嘱给予甘露醇250ml静脉滴注,要求30分钟滴完。护士应调节滴速为
替代手工记账的单位,应具备的条件有()。
应当从轻、减轻行政处罚的有()。
某有限责任公司2014年的工资薪金总额为950万元,支出的职工福利费为150万元,在计算该公司2014年的应纳税所得额时,支出的职工福利费用应据实扣除。()
艾森克儿童人格问卷适用的年龄范围是()的儿童。
海洋权益是国家领土向海洋延伸形成的权益。下图为我国海洋权益范围划分示意图。据此完成第19、20题。我国可在专属经济区进行海洋资源开发与管理。下列属于专属经济区的是()。
对立统一规律是唯物辩证法的实质和核心。()
以下程序用来建立一个10*10矩阵,该矩阵两条对角线上的元素为1,其余元素为0,请补充完该程序。该程序运行结果见下图。PrivateSubForm_click()Dims(10,10)AsInt
StudiesoftheWeddellsealinthelaboratoryhavedescribedthephysiologicalmechanismsthatallowthesealtocopewiththee
最新回复
(
0
)