Native American history is re-examined using a large dataset of pre-Columbian mitochondrial genomes

What is it about?

We sequenced 92 whole mitochondrial genomes from pre-Columbian South American skeletons dating from 8.6–0.5 kya, allowing a detailed, temporally calibrated reconstruction of the peopling of the Americas. The data suggest a small population entered the Americas via a coastal route around 16.0 kya, previously having been isolated in eastern Beringia for ~2.4–9 ky after separation from eastern Siberian populations. Following a rapid movement throughout the Americas, limited gene flow in South America resulted in marked geographic isolation of populations, which persisted through time. All the ancient mitochondrial lineages detected in this study were absent from modern datasets, suggesting a high extinction rate. Further analyses supported a scenario where the combination of marked population isolation and European colonization caused a substantial loss of pre-Columbian genetic lineages.

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Why is it important?

Linguistic and genetic evidence show that humans migrated from Siberia into the Americas, crossing the land bridge—submerged under the Bering Strait today—that connected Eastern Siberia and Alaska during the last Ice Age. Archaeological evidence indicates human presence as far as southern Chile by 14.6 kya (thousand years ago), shortly after the last Ice Age ice sheets blocking access to North America proper began to retreat. However, the exact timing, route, and process of the initial peopling of the Americas remain uncertain despite much research.