搜索关注在线英语听力室公众号:tingroom,领取免费英语资料大礼包。
(单词翻译)
A new study shows that there was mixing between ancient native peoples from Polynesia and South America.
Researchers say they found a single episode of the two groups interbreeding around 800 years ago after a long trip across the Pacific Ocean.
For a long time, the question of such contact had been debated among scientists. The contact was theorized partly because of the presence of a kind of sweet potato in the islands of Polynesia. The plant is native to South and Central America.
Scientists said last week that an examination of DNA1 from 807 people made the results clear. The genetic2 material came from 14 Polynesian islands and Pacific coastal3 Native American populations from Mexico to Chile.
People from four island areas in French Polynesia had DNA that showed interbreeding with South Americans at around the year 1200. Those South Americans were most closely related to present-day native Colombians.
The islands are about 6,800 kilometers from South America.
People from Easter Island also had South American ancestry4, some from modern Chilean immigrants and some from the same ancient mixing as the other islands.
Easter Island, which belongs to Chile, was settled sometime after the interbreeding 800 years ago. The island, which lies 3,700 kilometers west of South America, is known for its massive stone statues.
The study left open the question of who crossed the Pacific Ocean. Were Polynesians traveling east and arriving in Colombia or maybe Ecuador? Or were South Americans traveling west?
Alexander Ioannidis is a computational geneticist at Stanford University in California. He was the lead author of the research, which appears in the science journal Nature.
Ioannadis says he thinks the Polynesians crossed the Pacific, since they were "exploring the ocean and discovering some of the most distant Pacific islands around exactly the time of contact." The Reuters news agency reported his comments.
If the Polynesians reached the Americas, he added, they probably traveled in sailing canoes with two hulls5. He noted7 these boats operate much like a modern catamaran, another kind of two-hulled boat.
The contact explains the mystery of how the sweet potato arrived in Polynesia centuries before European sailors. Ioannidis noted the vegetable's name in many Polynesian languages - kumara - sounds similar to its name in some languages spoken in the Andes Mountains.
I'm Alice Bryant.
Words in This Story
episode - n. an event or a short period of time that is important or unusual
interbreed - v. to breed or cause to breed with another of a different race or species
theorize - v. to think of or suggest ideas about what is possibly true or real : to form or suggest a theory about something
DNA - n. a substance that carries genetic information in the cells of plants and animals — often used before another noun
author - n. a person who has written something
hull6 - n. the main body of a boat or ship, including the bottom, sides, and deck but not the masts and other parts
1 DNA | |
(缩)deoxyribonucleic acid 脱氧核糖核酸 | |
参考例句: |
|
|
2 genetic | |
adj.遗传的,遗传学的 | |
参考例句: |
|
|
3 coastal | |
adj.海岸的,沿海的,沿岸的 | |
参考例句: |
|
|
4 ancestry | |
n.祖先,家世 | |
参考例句: |
|
|
5 hulls | |
船体( hull的名词复数 ); 船身; 外壳; 豆荚 | |
参考例句: |
|
|
6 hull | |
n.船身;(果、实等的)外壳;vt.去(谷物等)壳 | |
参考例句: |
|
|
7 noted | |
adj.著名的,知名的 | |
参考例句: |
|
|
本文本内容来源于互联网抓取和网友提交,仅供参考,部分栏目没有内容,如果您有更合适的内容,欢迎 点击提交 分享给大家。