RESEARCH CONCLUSIONS: New genetic research led by the Genographic Project consortium shows a distinctive ancestry for the Uros populations of Peru and Bolivia that predates the arrival of the Spanish conquistadores and may date back to the earliest settlement of the Altiplano, or high plain, of the central Andes some 3,700 years ago. Despite the fact that the Uros today share many lineages with the surrounding Andean populations, they have maintained their own divergent genetic ancestry.

WHO ARE THE UROS?: The Uros are a self-identified ethnic group, about 2,000 of whom live in Peru, many of them on artificial floating islands on Lake Titicaca. Another 2,600 individuals live beside lakes and rivers of Bolivia. According to some anthropologists, the Uros are descendants of the first settlers of the Altiplano -- the Andean plateau -- yet their origin has been subjected to considerable academic debate. Those from Peru have long claimed to descend from the ancient Urus (Uruquilla speakers), using their differentiated ethnic identity to assert rights and prerogatives for their use of Titicaca's natural resources. The Uros have historically been the target of discrimination by the pre-Inca, Inca and the Spanish, and this continues today. Some people have alleged that the Uros disappeared a long time ago and that the new islanders have conjured up an ancient heritage in order to attract tourists and receive special recognition and rights.

SCIENTIFIC PAPER PUBLICATION: A paper on the research, "The Genetic History of Indigenous Populations of the Peruvian and Bolivian Altiplano: The Legacy of the Uros," will be published Sept. 11 by the journal PLOS ONE. The paper is embargoed until 5 p.m. (ET, U.S.) Wednesday, Sept. 11, 2013, and is at: http://dx. plos. org/ 10. 1371/ journal. pone. 0073006

QUOTES FROM AUTHORS: "We have found a concrete connection to the distinctive past for the Uros," said Fabricio R. Santos, professor at the Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil, the leading coauthor of the paper. "When we shared this information with the Uros people, they were quite enthusiastic about the news," said Professor Ricardo Fujita of the Universidad San Martin de Porres, Lima, Peru, coauthor of the paper.

"We were excited to observe some Y lineages only found among the Uros," said Professor José R. Sandoval at the Universidad San Martin de Porres, Lima, Peru, first author of the paper and a Peruvian Aymara born on the shores of Lake Titicaca.

"The timing of human settlement in the Andean Altiplano is one of the great mysteries of our species' worldwide odyssey -- a vast, high-altitude plain that seems utterly inhospitable, yet it has apparently nurtured a complex culture for millennia," said Spencer Wells, Genographic Project director and National Geographic Explorer-in-Residence. "This significant new study reflects the importance of the Genographic team's careful, patient work with the members of the indigenous communities living in this remote corner of the mountainous South American terrain, and sheds light on how our species has adapted to disparate ecosystems since its relatively recent exodus from an African homeland less than 70,000 years ago."

RESEARCH METHODS: Representatives of the Genographic Project, which uses project leaders compared the Uros' haplotype (genetic lineages) profiles with those of eight Aymara-, nine Quechua- and two Arawak-speaking populations from the western region of South America.

BACKGROUND ON UROS: The Andean highlands are home to a vast indigenous population of several million, mostly Aymaras and Quechuas. The Uros are a minority group that consider themselves descendants of the ancient Urus, who are generally recognized as the first major ethnic group to have settled in the Andes, specifically the Lake Titicaca watershed. As a result of successive invasions by Aymara populations and the Incas, an increasing proportion of the Uros became confined to floating islands and small villages around the lake. Today, the Uros of Peru and Bolivia are also known as Qhas Qut suñi, which means "people of the lake" in the ancient Uruquilla language. Their economy was originally based on aquatic resources, especially fishing, bird hunting and gathering of bird eggs. Using the lake's reeds for construction of islands, houses and handicrafts for tourism, the Uros have become a fascination to visitors, and the Altiplano is now Peru's second most important tourist destination.

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AUTHORS AVAILABLE FOR INTERVIEW: Fabricio R. Santos, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil; Ricardo Fujita and José Raúl Sandoval, Universidad San Martin de Porres, Lima, Peru; and Spencer Wells, Genographic Project director and National Geographic Explorer-in-Residence, Washington, D.C., United States.

CONTACT: Colby Bishop, National Geographic, cbishop@ngs.org; Luana Macieira, Universidade Federal de Minas Gerais, macieira.luana@gmail.com

PHOTOGRAPHS: A selection of color photographs from the field