科学家称美洲的第一批人至少在16600年前到达

Scientists: First People in Americas Arrived at Least 16,600 Years Ago

Stone tools and pieces of animal bone from about 16,600 years ago are the earliest evidence yet of human beings in the New World, scientists say.

The objects were found in the western United States. They were recovered from an archeological site called Cooper’s Ferry on the Salmon¹ River near the town of Cottonwood, Idaho.

Scientists used radiocarbon dating methods to find out how old these artifacts are.

The scientists say people lived in or passed through the area at a time when ice covered large parts of North America. That period of time is known as Earth’s Ice Age. During the period, big mammals like mastodons, saber-toothed cats and camels lived in North America.

Loren Davis is an anthropology² professor at Oregon State University. He led the team of scientists working at Cooper’s Ferry. A report on the study and their findings was published in Science magazine.

“The Cooper’s Ferry site is the earliest radiocarbon-dated archaeological evidence in the America’s,” Davis said.

The researchers said the artifacts suggest that people first lived in the area between 16,600 and 15,300 years ago and returned to live there many times after that.

The oldest objects include four sharp stone tools, which were used for cutting and scraping. The scientists also found pieces of stone left from making the tools. They also found burnt pieces of wood, rock that had been split³ by heat from fires as well as particles of animal bone particles and pieces of horses’ teeth. Horses were once native to North America but later disappeared.

A long trip around the world

Scientists say humans first appeared in Africa about 300,000 years ago and later spread throughout the world. There has been much scientific debate about when humans first entered the Americas. They are believed to have crossed into North America at a time when Siberia and Alaska were connected by land.

The new findings support the hypothesis⁴ that the first human migration⁵ into the Americas traveled down the Pacific coast instead of an inland path.

Davis said, “The Columbia River would provide the first Americans their first route to interior⁶ lands south of the continental⁷ ice sheets.” The Columbia is the biggest river flowing into the Pacific Ocean from North America. It might have provided a way for the early migrants to travel into the North American land mass.

The researchers noted⁸ details of some of the sharp objects that would have been used for hunting. These artifacts appear similar to those found in northern Japan from a somewhat earlier date.

Davis said, “We hypothesize that this may signal a cultural connection between early peoples who lived around the northern Pacific Rim⁹.”

“Traditional technological¹⁰ ideas spread from northeastern Asia into North America at the end of the last glacial period,” he added.

I’m Mario Ritter, Jr.

Words in This Story

archeological – adj. related to the study of the life of people in the past

hypothesis – n. an idea or theory that is not proven but leads to further study

route – n. a path to get from one place to another

interior – n. the part of a land area that is away from the coast

glacial – adj. having to do with glaciers, huge areas of thick ice

1 salmon   

n.鲑，大马哈鱼，橙红色的

参考例句：

• We saw a salmon jumping in the waterfall there.我们看见一条大马哈鱼在那边瀑布中跳跃。
• Do you have any fresh salmon in at the moment?现在有新鲜大马哈鱼卖吗？

2 anthropology   

n.人类学

参考例句：

• I believe he has started reading up anthropology.我相信他已开始深入研究人类学。
• Social anthropology is centrally concerned with the diversity of culture.社会人类学主要关于文化多样性。

3 split   

n.劈开，裂片，裂口；adj.分散的；v.分离，分开，劈开

参考例句：

• Who told you that Mary and I had split up?谁告诉你玛丽和我已经离婚了？
• The teacher split the class up into six groups.老师把班级分成6个小组。

4 hypothesis   

n.假说，假设，(无根据的)猜测，揣测

参考例句：

• We have proved the hypothesis.我们已经证明了这种假设。
• The results confirmed his hypothesis on the use of modal verbs.结果证实了他的关于情态动词用法的假设。

5 migration   

n.迁移，移居，（鸟类等的）迁徙

参考例句：

• Swallows begin their migration south in autumn.燕子在秋季开始向南方迁移。
• He described the vernal migration of birds in detail.他详细地描述了鸟的春季移居。

6 interior   

adj.在内的，内部的，内地的，国内的；n.内部

参考例句：

• There is water in the interior of the cave.在山洞的内部有水。
• They went into the interior room.他们进了内室。

7 continental   

adj.大陆的，大陆性的，欧洲大陆的

参考例句：

• A continental climate is different from an insular one.大陆性气候不同于岛屿气候。
• The most ancient parts of the continental crust are 4000 million years old.大陆地壳最古老的部分有40亿年历史。

8 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

9 rim   

n.(圆物的)边，轮缘；边界

参考例句：

• The water was even with the rim of the basin.盆里的水与盆边平齐了。
• She looked at him over the rim of her glass.她的目光越过玻璃杯的边沿看着他。

10 technological   

adj.技术的；工艺的

参考例句：

• A successful company must keep up with the pace of technological change.一家成功的公司必须得跟上技术变革的步伐。
• Today,the pace of life is increasing with technological advancements.当今， 随着科技进步，生活节奏不断增快。