首页
登录
职称英语
"Migration from Asia" The Asian migration hypothesis is
"Migration from Asia" The Asian migration hypothesis is
游客
2025-02-09
13
管理
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. [br] Why does the author mention blood types in paragraph 3?
选项
A、Blood types offered proof that the migration had come from Scandinavia.
B、The presence of type B in Native Americans was evidence of the migration.
C、The blood typing was similar to data from both Japan and Scandinavia.
D、Comparisons of blood types in Asia and North America established the date of migration.
答案
D
解析
... the migrations must have begun before the evolution of type B." Choice A is not correct because the time frame was the same as the settlement of Scandinavia, but the origin of the migration was not Scandinavian. Choice B is not correct because almost no Native Americans have type B. Choice C is not correct because the blood typing was done with Native Americans and Asians, not Scandinavians.
转载请注明原文地址:http://tihaiku.com/zcyy/3948771.html
相关试题推荐
BIRDMIGRATIONABirdshavemanyuniquedesignfeaturesthatenablethemtoperf
BIRDMIGRATIONABirdshavemanyuniquedesignfeaturesthatenablethemtoperf
BIRDMIGRATIONABirdshavemanyuniquedesignfeaturesthatenablethemtoperf
BIRDMIGRATIONABirdshavemanyuniquedesignfeaturesthatenablethemtoperf
ThemigrationofAfricanAmericansfromtheruralSouthtothe(industrial)Nort
ThemuseumonEllisIsland,aformerimmigrationstation,containsdocumentsand
"MigrationfromAsia"TheAsianmigrationhypothesisis
"MigrationfromAsia"TheAsianmigrationhypothesisis
"MigrationfromAsia"TheAsianmigrationhypothesisis
"MigrationfromAsia"TheAsianmigrationhypothesisis
随机试题
Tokyoisaconfusingcitymainlybecause______.[br]InTokyo,thebestwayfor
[originaltext]M:Hey,Sophia,howareyoudoing?W:Hi,Bob.I’mgood,thanks.
_________________________(直到截止日他才寄出)hisapplicationform.Itwasnotuntilthe
软交换是网络演进以及下一代()的核心设备之一。A.分组网络 B.电话网络
孕妇感染梅毒正确的是A.母婴垂直传播是重要传播途径 B.早期妊娠发现并确诊,应
手术区皮肤消毒区域包括手术切口周围( )A.10cm的区域 B.15cm的区
质量策划的关键是()。A.制定质量目标并设法使其实现 B.监督产品质量 C
如果股价原有的趋势是向上,形成上升三角形的整理形态,股价今后的走势可能会()。A
案例一(6): 第三次咨询: 求助者:我按您的建议到精神科去查了一下,去了两
会计人员强化服务意识具体要做到()。A、摆正自己的工作位置 B、做到谦虚谨慎,
最新回复
(
0
)