首页
登录
职称英语
"Migration from Asia" The Asian migration hypothesis is today supported by mo
"Migration from Asia" The Asian migration hypothesis is today supported by mo
游客
2024-01-03
34
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 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. [br] An introduction for a short summary of the passage appears below. Complete the summary by selecting the THREE answer choices that mention the most important points in the passage. Some sentences do not belong in the summary because they express ideas that are not included in the passage or are minor points from the passage. This question is worth 2 points.
There is considerable evidence supporting a theory of multiple migrations from Asia to the Americas.
-
-
-
Answer Choices
A Ancient stories of migrations from a faraway place are common in the cultures of many Native American nations.
B The people who inhabited Monte Verde in southern Chile were a highly evolved culture as evidenced by their tools and homes.
C Genetic similarities between Native American peoples and Asians include the arrangement of teeth, viruses, and blood types.
D Hunters followed the herds of big game from Beringia south along the Rocky Mountains into what is now called the Great Plains.
E Excavations at archaeological sites provide artifacts that can be used to date the various migrations that occurred by land and sea.
F The climate began to get warmer and warmer, melting the glacial ice about 13,000 b.c.e.
选项
答案
E, D, C
解析
summarize the passage. Choice A is a concluding point that is not developed with examples and details. Choice B is a minor point that supports major point E. Choice F is a minor point that supports major point D.
转载请注明原文地址:https://tihaiku.com/zcyy/3329451.html
相关试题推荐
HumanMigrationHumanmigration:thetermisvague.Whatpeo
HumanMigrationHumanmigration:thetermisvague.Whatpeo
HumanMigrationHumanmigration:thetermisvague.Whatpeo
HumanMigrationHumanmigration:thetermisvague.Whatpeo
HumanMigrationHumanmigration:thetermisvague.Whatpeo
HumanMigrationHumanmigration:thetermisvague.Whatpeo
HumanMigrationHumanmigration:thetermisvague.
HumanMigrationHumanmigration:thetermisvague.
HumanMigrationHumanmigration:thetermisvague.
HumanMigrationHumanmigration:thetermisvague.
随机试题
[originaltext]TheAmericanpatentsystem,providedforintheConstitution,
GrowingnumbersofGermansarebecomingaddictedtotext-messaging,aGerman
手动报警按钮分为()。A.可复位报警按钮 B.不可复位报警按钮 C.
生产性建设项目总投资包括建设投资、建设期利息两部分。
项目合同管理不包括( )。A.合同签订 B.合同履行 C.合同纠纷仲裁
A.腹壁反射 B.角膜反射 C.吸吮反射 D.脑膜刺激征 E.巴彬斯基征
擦洗棉布上的陈旧血渍用A.乙醇 B.草酸 C.过氧乙酸 D.漂白粉澄清液
一台三相电动机运行于中性点接地的低压电力系统中,操作员碰及外壳导致意外触电事故,
《卓越绩效评价准则》与ISO9000的相同点包括()。A.基本原理和原则相
在进行沥青贯入式路面施工时,深贯入式路面的沥青材料贯入深度为()A.2~3cm
最新回复
(
0
)