Person:

Lawson, Ann

We generated genome-wide DNA data from four children buried roughly 8000 and 3000 years ago at Shum Laka (Cameroon), one of the earliest archaeological sites within the probable homeland of Bantu languages. One individual carried the deeply divergent Y chromosome haplogroup A00, which is found today almost exclusively in the same region. However, all four individuals’ genome-wide ancestry profiles are most similar to West-Central African hunter-gatherers, implying that present-day populations in western Cameroon, as well as Bantu speakers across the continent, are not descended substantially from the population represented by these four people. We infer an Africa-wide phylogeny that features widespread admixture and three prominent radiations, including one giving rise to at least four major lineages deep in the history of modern humans.

Paleo-Eskimos were the first people to settle vast regions of the American Arctic around 5,000 years ago, and were subsequently joined and largely displaced around 1,000 years ago by ancestors of present-day Inuit and Yup’ik1-3. The genetic relationship between Paleo-Eskimos and Native American, Inuit, Yup’ik and Aleut populations remains uncertain4-7. Here we present new genomic data for 48 ancient individuals from Chukotka, East Siberia, the Aleutian Islands, Alaska, and the Canadian Arctic. We co-analyze these data with new data from present-day Alaskan Iñupiat and West Siberian populations and published genomes. Employing new methods based on rare allele and haplotype sharing as well as established methods4,8-10, we show that Paleo-Eskimo-related admixture is ubiquitous among populations speaking Na-Dene and Eskimo-Aleut languages. We develop a comprehensive model for the Holocene peopling events of Chukotka and North America, and show that several key migrations connected to the origin of the Na-Dene peoples, the peopling of the Aleutian Islands, and the spread of Yup’ik and Inuit across the Arctic region are genetically linked to a single Siberian source related to Paleo-Eskimos.