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
2012-01-14
40
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 icefree, 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 at 12,500 years ago, tong 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 Beringia had been submerged, 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.
Why does the author mention the settlement at Monte Verde, Chile, in paragraph 5?
选项
A、The remains of boats suggest that people may have lived there.
B、Artifacts suggest that humans reached this area before the ice melted on land.
C、Bones and footprints from large animals confirm that the people were hunters.
D、The houses and tools excavated prove that the early humans were intelligent.
答案
B
解析
"The most spectacular find, at Monte Verde in southern Chile, produced striking evidence of tool making, house building...before the highway had been cleared of ice." Choice A is not correct because archeologists believe that migration in boats may have occurred, but no boats were found. Choice C is not correct because the footprints found there were human, not those of large animals. Choice D is not correct because no conclusions were made about the intelligence of the early humans.
转载请注明原文地址:https://kaotiyun.com/show/uQyO777K
0
托福(TOEFL)
相关试题推荐
BIRDMIGRATIONABirdshavemanyuniquedesignfeaturesthatenablethemtoperformsuchamazingfeatsofendurance.Theyareeq
Choosethecorrectletter,A,B,CorD.Writethecorrectletterinboxes9-13onyouranswersheet.Accordingtothetext,wh
Choosethecorrectletter,A,B,CorD.Writethecorrectletterinboxesonyouranswersheet.Accordingtothepassage,iti
HowdesertsareformedA.Adesertreferstoabarrensectionofland,mainlyinaridandsemi-aridareas,wherethereisal
TheConceptofChildhoodinWesternCountriesThehistoryofchildhoodhasbeenaheatedtopicinsocialhistorysincetheh
TheStudyofChimpanzeeCultureA.Afterstudyingthesimilaritiesbetweenchimpanzeesandhumansforyears,researchershav
SECTION4Questions31-40Questions31-33CompletethefollowingsentencesusingNOMORETHANTHREEWORDSAND/ORNUMBERSfore
Gestures—especially______ones.Put______onboardandstudentslabelit.
WriteNOMORETHANTWOWORDSforeachanswer.BeWellOnlineProgramme=interactivewebsitewithresourcestohelpreach
随机试题
在考生文件夹下存在一个数据库“Acc3.mdb”,其中已经设计了表对象“职工”、窗体对象“fform”、报表对象“frepo”和宏对象“mos”。试在此基础上按照以下要求补充设计,最终效果如图6所示。(1)将报表“frepo”的报表页眉区内名为“fti
我国对资本主义工商业的社会主义改造所采取的基本政策是()
—Helookssoyoung!—Iagreewithyou.Helooks30,butheis______45.
慢性肺心病急性加重期关键性的治疗是正确应用
入汤剂宜包煎的药物是
全空气系统过渡季或冬季增大新风比运行,其主要目的是:
根据《个人独资企业法》的规定,下列各项中,可以用作个人独资企业名称的有()。
二元式中央银行制度具有权利与职能相对分散,分支机构较少等特点,实行这种中央银行组织形式的国家或地区是()。
教学过程中,学生学习是在教师指导下进行的,这说明学生的认识具有特殊性,表现在()。
用命令“INDEXON姓名TAGindexname”建立索引,其索引类型是()。
最新回复
(
0
)