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1.
Science ; 320(5884): 1787-9, 2008 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-18511654

RESUMO

The Paleo-Eskimo Saqqaq and Independence I cultures, documented from archaeological remains in Northern Canada and Greenland, represent the earliest human expansion into the New World's northern extremes. However, their origin and genetic relationship to later cultures are unknown. We sequenced a mitochondrial genome from a Paleo-Eskimo human by using 3400-to 4500-year-old frozen hair excavated from an early Greenlandic Saqqaq settlement. The sample is distinct from modern Native Americans and Neo-Eskimos, falling within haplogroup D2a1, a group previously observed among modern Aleuts and Siberian Sireniki Yuit. This result suggests that the earliest migrants into the New World's northern extremes derived from populations in the Bering Sea area and were not directly related to Native Americans or the later Neo-Eskimos that replaced them.


Assuntos
DNA Mitocondrial/genética , Genoma Mitocondrial , Inuíte/genética , Povo Asiático/genética , Emigração e Imigração , Feminino , Genética Populacional , Groenlândia , Cabelo/química , Haplótipos , História Antiga , Humanos , Indígenas Norte-Americanos/genética , Inuíte/classificação , Inuíte/história , Masculino , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA
2.
Science ; 317(5834): 111-4, 2007 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-17615355

RESUMO

It is difficult to obtain fossil data from the 10% of Earth's terrestrial surface that is covered by thick glaciers and ice sheets, and hence, knowledge of the paleoenvironments of these regions has remained limited. We show that DNA and amino acids from buried organisms can be recovered from the basal sections of deep ice cores, enabling reconstructions of past flora and fauna. We show that high-altitude southern Greenland, currently lying below more than 2 kilometers of ice, was inhabited by a diverse array of conifer trees and insects within the past million years. The results provide direct evidence in support of a forested southern Greenland and suggest that many deep ice cores may contain genetic records of paleoenvironments in their basal sections.


Assuntos
Aminoácidos/análise , DNA/análise , Ecossistema , Camada de Gelo/química , Invertebrados , Plantas , Árvores , Aminoácidos/história , Aminoácidos/isolamento & purificação , Animais , Teorema de Bayes , Clima , DNA/história , DNA/isolamento & purificação , Fósseis , Geografia , Groenlândia , História Antiga , Invertebrados/classificação , Invertebrados/genética , Plantas/classificação , Plantas/genética , Reação em Cadeia da Polimerase , Tempo
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