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2.
Nature ; 555(7695): 190-196, 2018 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-29466337

RESUMEN

From around 2750 to 2500 bc, Bell Beaker pottery became widespread across western and central Europe, before it disappeared between 2200 and 1800 bc. The forces that propelled its expansion are a matter of long-standing debate, and there is support for both cultural diffusion and migration having a role in this process. Here we present genome-wide data from 400 Neolithic, Copper Age and Bronze Age Europeans, including 226 individuals associated with Beaker-complex artefacts. We detected limited genetic affinity between Beaker-complex-associated individuals from Iberia and central Europe, and thus exclude migration as an important mechanism of spread between these two regions. However, migration had a key role in the further dissemination of the Beaker complex. We document this phenomenon most clearly in Britain, where the spread of the Beaker complex introduced high levels of steppe-related ancestry and was associated with the replacement of approximately 90% of Britain's gene pool within a few hundred years, continuing the east-to-west expansion that had brought steppe-related ancestry into central and northern Europe over the previous centuries.


Asunto(s)
Evolución Cultural/historia , Genoma Humano/genética , Genómica , Migración Humana/historia , Cromosomas Humanos Y/genética , ADN Antiguo , Europa (Continente) , Pool de Genes , Genética de Población , Haplotipos , Historia Antigua , Humanos , Masculino , Análisis Espacio-Temporal
3.
Genome Res ; 25(4): 459-66, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25770088

RESUMEN

It is commonly thought that human genetic diversity in non-African populations was shaped primarily by an out-of-Africa dispersal 50-100 thousand yr ago (kya). Here, we present a study of 456 geographically diverse high-coverage Y chromosome sequences, including 299 newly reported samples. Applying ancient DNA calibration, we date the Y-chromosomal most recent common ancestor (MRCA) in Africa at 254 (95% CI 192-307) kya and detect a cluster of major non-African founder haplogroups in a narrow time interval at 47-52 kya, consistent with a rapid initial colonization model of Eurasia and Oceania after the out-of-Africa bottleneck. In contrast to demographic reconstructions based on mtDNA, we infer a second strong bottleneck in Y-chromosome lineages dating to the last 10 ky. We hypothesize that this bottleneck is caused by cultural changes affecting variance of reproductive success among males.


Asunto(s)
Cromosomas Humanos Y/genética , Evolución Molecular , Grupos Raciales/genética , Secuencia de Bases , ADN Mitocondrial/genética , Variación Genética/genética , Genética de Población , Haplotipos/genética , Humanos , Masculino , Modelos Genéticos , Filogenia , Análisis de Secuencia de ADN
4.
Am J Hum Genet ; 95(5): 584-589, 2014 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-25449608

RESUMEN

Arctic populations live in an environment characterized by extreme cold and the absence of plant foods for much of the year and are likely to have undergone genetic adaptations to these environmental conditions in the time they have been living there. Genome-wide selection scans based on genotype data from native Siberians have previously highlighted a 3 Mb chromosome 11 region containing 79 protein-coding genes as the strongest candidates for positive selection in Northeast Siberians. However, it was not possible to determine which of the genes might be driving the selection signal. Here, using whole-genome high-coverage sequence data, we identified the most likely causative variant as a nonsynonymous G>A transition (rs80356779; c.1436C>T [p.Pro479Leu] on the reverse strand) in CPT1A, a key regulator of mitochondrial long-chain fatty-acid oxidation. Remarkably, the derived allele is associated with hypoketotic hypoglycemia and high infant mortality yet occurs at high frequency in Canadian and Greenland Inuits and was also found at 68% frequency in our Northeast Siberian sample. We provide evidence of one of the strongest selective sweeps reported in humans; this sweep has driven this variant to high frequency in circum-Arctic populations within the last 6-23 ka despite associated deleterious consequences, possibly as a result of the selective advantage it originally provided to either a high-fat diet or a cold environment.

5.
Nat Ecol Evol ; 3(5): 765-771, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30988490

RESUMEN

The roles of migration, admixture and acculturation in the European transition to farming have been debated for over 100 years. Genome-wide ancient DNA studies indicate predominantly Aegean ancestry for continental Neolithic farmers, but also variable admixture with local Mesolithic hunter-gatherers. Neolithic cultures first appear in Britain circa 4000 BC, a millennium after they appeared in adjacent areas of continental Europe. The pattern and process of this delayed British Neolithic transition remain unclear. We assembled genome-wide data from 6 Mesolithic and 67 Neolithic individuals found in Britain, dating 8500-2500 BC. Our analyses reveal persistent genetic affinities between Mesolithic British and Western European hunter-gatherers. We find overwhelming support for agriculture being introduced to Britain by incoming continental farmers, with small, geographically structured levels of hunter-gatherer ancestry. Unlike other European Neolithic populations, we detect no resurgence of hunter-gatherer ancestry at any time during the Neolithic in Britain. Genetic affinities with Iberian Neolithic individuals indicate that British Neolithic people were mostly descended from Aegean farmers who followed the Mediterranean route of dispersal. We also infer considerable variation in pigmentation levels in Europe by circa 6000 BC.


Asunto(s)
ADN Antiguo , Genoma , Europa (Continente) , Humanos , Dinámica Poblacional , Reino Unido
6.
Nat Ecol Evol ; 3(6): 986-987, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31068681

RESUMEN

In the version of this Article originally published, there were errors in the colour ordering of the legend in Fig. 5b, and in the positions of the target and surrogate populations in Fig. 5c. This has now been corrected. The conclusions of the study are in no way affected. The errors have been corrected in the HTML and PDF versions of the article.

7.
Science ; 360(6392): 1024-1027, 2018 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-29853687

RESUMEN

Little is known regarding the first people to enter the Americas and their genetic legacy. Genomic analysis of the oldest human remains from the Americas showed a direct relationship between a Clovis-related ancestral population and all modern Central and South Americans as well as a deep split separating them from North Americans in Canada. We present 91 ancient human genomes from California and Southwestern Ontario and demonstrate the existence of two distinct ancestries in North America, which possibly split south of the ice sheets. A contribution from both of these ancestral populations is found in all modern Central and South Americans. The proportions of these two ancestries in ancient and modern populations are consistent with a coastal dispersal and multiple admixture events.


Asunto(s)
Evolución Biológica , Emigración e Inmigración , Genoma Humano , Población/genética , California , Humanos , Ontario
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