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2.
Nature ; 557(7705): 418-423, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29743673

RESUMEN

Hepatitis B virus (HBV) is a major cause of human hepatitis. There is considerable uncertainty about the timescale of its evolution and its association with humans. Here we present 12 full or partial ancient HBV genomes that are between approximately 0.8 and 4.5 thousand years old. The ancient sequences group either within or in a sister relationship with extant human or other ape HBV clades. Generally, the genome properties follow those of modern HBV. The root of the HBV tree is projected to between 8.6 and 20.9 thousand years ago, and we estimate a substitution rate of 8.04 × 10-6-1.51 × 10-5 nucleotide substitutions per site per year. In several cases, the geographical locations of the ancient genotypes do not match present-day distributions. Genotypes that today are typical of Africa and Asia, and a subgenotype from India, are shown to have an early Eurasian presence. The geographical and temporal patterns that we observe in ancient and modern HBV genotypes are compatible with well-documented human migrations during the Bronze and Iron Ages1,2. We provide evidence for the creation of HBV genotype A via recombination, and for a long-term association of modern HBV genotypes with humans, including the discovery of a human genotype that is now extinct. These data expose a complexity of HBV evolution that is not evident when considering modern sequences alone.


Asunto(s)
Evolución Molecular , Virus de la Hepatitis B/genética , Virus de la Hepatitis B/aislamiento & purificación , Hepatitis B/virología , Filogenia , África , Animales , Asia , Europa (Continente) , Genotipo , Virus de la Hepatitis B/clasificación , Historia Antigua , Historia Medieval , Hominidae/virología , Migración Humana/historia , Humanos , Recombinación Genética
4.
Nature ; 557(7705): 369-374, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29743675

RESUMEN

For thousands of years the Eurasian steppes have been a centre of human migrations and cultural change. Here we sequence the genomes of 137 ancient humans (about 1× average coverage), covering a period of 4,000 years, to understand the population history of the Eurasian steppes after the Bronze Age migrations. We find that the genetics of the Scythian groups that dominated the Eurasian steppes throughout the Iron Age were highly structured, with diverse origins comprising Late Bronze Age herders, European farmers and southern Siberian hunter-gatherers. Later, Scythians admixed with the eastern steppe nomads who formed the Xiongnu confederations, and moved westward in about the second or third century BC, forming the Hun traditions in the fourth-fifth century AD, and carrying with them plague that was basal to the Justinian plague. These nomads were further admixed with East Asian groups during several short-term khanates in the Medieval period. These historical events transformed the Eurasian steppes from being inhabited by Indo-European speakers of largely West Eurasian ancestry to the mostly Turkic-speaking groups of the present day, who are primarily of East Asian ancestry.


Asunto(s)
Pueblo Asiatico/genética , Genoma Humano/genética , Pradera , Filogenia , Población Blanca/genética , Asia/etnología , Europa (Continente)/etnología , Agricultores/historia , Historia Antigua , Migración Humana/historia , Humanos
5.
Science ; 360(6396)2018 06 29.
Artículo en Inglés | MEDLINE | ID: mdl-29743352

RESUMEN

The Yamnaya expansions from the western steppe into Europe and Asia during the Early Bronze Age (~3000 BCE) are believed to have brought with them Indo-European languages and possibly horse husbandry. We analyzed 74 ancient whole-genome sequences from across Inner Asia and Anatolia and show that the Botai people associated with the earliest horse husbandry derived from a hunter-gatherer population deeply diverged from the Yamnaya. Our results also suggest distinct migrations bringing West Eurasian ancestry into South Asia before and after, but not at the time of, Yamnaya culture. We find no evidence of steppe ancestry in Bronze Age Anatolia from when Indo-European languages are attested there. Thus, in contrast to Europe, Early Bronze Age Yamnaya-related migrations had limited direct genetic impact in Asia.


Asunto(s)
Pueblo Asiatico/genética , Domesticación , Flujo Genético , Genoma Humano , Caballos , Migración Humana/historia , Animales , Asia , Cromosomas Humanos Y/genética , ADN Antiguo , ADN Mitocondrial/genética , Europa (Continente) , Pradera , Historia Antigua , Humanos , Lenguaje , Secuenciación Completa del Genoma
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