[ti:Study: Ancient Polynesians and South Americans Had Contact] [by:www.51voa.com] [00:00.00]更多听力请访问51VOA.COM [00:00.04]A new study shows that there was mixing between [00:04.28]ancient native peoples from Polynesia and South America. [00:10.04]Researchers say they found a single episode of the two groups [00:15.12]interbreeding around 800 years ago after a long trip across the Pacific Ocean. [00:22.80]For a long time, the question of such contact had been debated among scientists. [00:30.00]The contact was theorized partly because of the presence [00:34.64]of a kind of sweet potato in the islands of Polynesia. [00:40.32]The plant is native to South and Central America. [00:45.84]Scientists said last week that an examination of DNA [00:50.96]from 807 people made the results clear. [00:56.68]The genetic material came from 14 Polynesian islands [01:01.92]and Pacific coastal Native American populations from Mexico to Chile. [01:09.96]People from four island areas in French Polynesia had DNA [01:15.48]that showed interbreeding with South Americans at around the year 1200. [01:23.04]Those South Americans were most closely related [01:27.24]to present-day native Colombians. [01:31.68]The islands are about 6,800 kilometers from South America. [01:39.12]People from Easter Island also had South American ancestry, [01:44.60]some from modern Chilean immigrants [01:48.32]and some from the same ancient mixing as the other islands. [01:54.28]Easter Island, which belongs to Chile, [01:57.76]was settled sometime after the interbreeding 800 years ago. [02:04.56]The island, which lies 3,700 kilometers west of South America, [02:11.96]is known for its massive stone statues. [02:17.12]The study left open the question of who crossed the Pacific Ocean. [02:23.44]Were Polynesians traveling east [02:26.40]and arriving in Colombia or maybe Ecuador? [02:30.44]Or were South Americans traveling west? [02:35.28]Alexander Ioannidis is a computational geneticist [02:40.28]at Stanford University in California. [02:44.76]He was the lead author of the research, [02:47.48]which appears in the science journal Nature. [02:52.32]Ioannadis says he thinks the Polynesians crossed the Pacific, [02:57.96]since they were "exploring the ocean and discovering [03:02.20]some of the most distant Pacific islands around exactly the time of contact." [03:09.64]The Reuters news agency reported his comments. [03:14.72]If the Polynesians reached the Americas, he added, [03:19.16]they probably traveled in sailing canoes with two hulls. [03:24.92]He noted these boats operate much like a modern catamaran, [03:30.44]another kind of two-hulled boat. [03:34.64]The contact explains the mystery of how the sweet potato arrived [03:39.96]in Polynesia centuries before European sailors. [03:45.24]Ioannidis noted the vegetable's name [03:48.72]in many Polynesian languages - kumara - sounds similar to its name [03:55.28]in some languages spoken in the Andes Mountains. [04:00.48]I'm Alice Bryant. 更多听力请访问51VOA.COM