Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 4 de 4
2.
Nature ; 557(7705): 418-423, 2018 05.
Article En | MEDLINE | ID: mdl-29743673

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.


Evolution, Molecular , Hepatitis B virus/genetics , Hepatitis B virus/isolation & purification , Hepatitis B/virology , Phylogeny , Africa , Animals , Asia , Europe , Genotype , Hepatitis B virus/classification , History, Ancient , History, Medieval , Hominidae/virology , Human Migration/history , Humans , Recombination, Genetic
3.
Science ; 360(6396)2018 06 29.
Article En | MEDLINE | ID: mdl-29743352

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.


Asian People/genetics , Domestication , Genetic Drift , Genome, Human , Horses , Human Migration/history , Animals , Asia , Chromosomes, Human, Y/genetics , DNA, Ancient , DNA, Mitochondrial/genetics , Europe , Grassland , History, Ancient , Humans , Language , Whole Genome Sequencing
4.
Science ; 360(6384): 111-114, 2018 Apr 06.
Article En | MEDLINE | ID: mdl-29472442

The Eneolithic Botai culture of the Central Asian steppes provides the earliest archaeological evidence for horse husbandry, ~5500 years ago, but the exact nature of early horse domestication remains controversial. We generated 42 ancient-horse genomes, including 20 from Botai. Compared to 46 published ancient- and modern-horse genomes, our data indicate that Przewalski's horses are the feral descendants of horses herded at Botai and not truly wild horses. All domestic horses dated from ~4000 years ago to present only show ~2.7% of Botai-related ancestry. This indicates that a massive genomic turnover underpins the expansion of the horse stock that gave rise to modern domesticates, which coincides with large-scale human population expansions during the Early Bronze Age.


Horses/classification , Horses/genetics , Animals , DNA, Ancient , Genome , Horses/anatomy & histology , Phenotype , Phylogeny
...