DNA reveals 1,500 Years of Chono Population History in Chilean Patagonia
– 4 min read
Peopling the Southern Cone and Patagonia: Ancient DNA Reveals Maritime Heritage
Peopling the Southern Cone and Patagonia: Ancient DNA Reveals Maritime Heritage
Introduction: The Far Southern Americas
The Southern Cone of the Americas encompasses the vast territories of modern Chile and Argentina, extending down to the windswept archipelagos of Patagonia. This region presents one of archaeology's most compelling questions: who were the first people to reach these remote lands, when did they arrive, and how did they adapt to some of Earth's most challenging environments? To answer these questions, researchers have combined archaeology, climate history, and ancient DNA analysis from sites scattered across remote coasts and islands.
The First South Americans: Reaching the End of the World
According to current evidence, people began migrating into the Americas between approximately 23,000 and 16,000 years ago, likely following Pacific coastal routes from Beringia, the icy region connecting Siberia and Alaska. Archaeological evidence from Chile demonstrates the remarkable speed of this southward expansion. At Monte Verde, near Puerto Montt, human occupation dates to between 18,500 and 14,500 years ago, with the most secure dates around 14,500 years ago. This means that within just a few thousand years of first entering the continent, humans had reached its southern extremity.
Monte Verde stands as one of archaeology's most extraordinary sites, preserving what appears to be a frozen village scene complete with wooden structures, sophisticated tools, and preserved plant remains that demonstrate complex landscape exploitation. By approximately 13,000 years ago, radiocarbon evidence suggests that much of present-day Chile was already occupied by human populations.
Patagonia: Maritime Adaptations in a Complex Landscape
Within the Southern Cone, Patagonia forms the great southern belt stretching from Argentina's windswept plains to Chile's intricate maze of Pacific fjords and islands. This landscape, shaped by repeated glaciations and volcanic eruptions, has seen dramatic coastline changes over millennia. Along the southwestern coast, ancient inhabitants developed sophisticated maritime adaptations, evidenced by archaeological traces of canoes, harbors, shoreline camps, and abundant remains of seals, fish, and shellfish.
When Europeans first entered southern Patagonia in the 16th century, they encountered three major seafaring groups: the Yagán, the Kawésqar, and the people they termed the "Chono". Stable isotope studies of human remains reveal that these communities literally built their bodies from marine resources, with diets overwhelmingly dominated by seafood. Recent ancient DNA research has provided crucial insights: seafaring life in Patagonia appears to have been a local innovation rather than an imported adaptation. Genetic continuity can be traced in the region from approximately 6,600 years ago, showing long-term stability with some intergroup contact but no large-scale population replacement.
The Chonos Archipelago: Life Among the Islands
The Chonos Archipelago, located between roughly 43° and 45° south on Chile's Pacific coast, forms the focal point of recent paleogenomic research. This vast island chain lies between Chiloé Island to the north and the Taitao Peninsula to the south, comprising more than 150 islands battered by over 3,000 millimeters of annual rainfall and average temperatures around 10°C. Sea level changes, glacial advances and retreats, and volcanic events have repeatedly altered shorelines, making archaeological site preservation challenging.
Despite these difficulties, careful fieldwork by archaeologists, particularly Omar Reyes, has revealed shell middens, camps, and burial places spanning the last 1,600 years. These sites provide the first detailed reconstruction of life in these remote islands, offering insights into one of the world's most specialized maritime cultures.
Ancient Individuals and Family Connections
The paleogenomic study analyzed 20 ancient individuals from eight archaeological sites across the Chonos Archipelago. These coastal sites, typically located near sheltered bays or channels, served as both living spaces and burial grounds. The burials, associated with thick shell middens and maritime tools, span from approximately 1,600 years before present to just a few centuries ago, bridging the gap to European contact.
Ancient DNA analysis has revealed intimate family relationships among the buried individuals. At Isla Yalac 1, researchers identified a first-degree relationship between IYA1 (male) and IYA6 (female), likely siblings or mother and son, both sharing the same maternal lineage and overlapping radiocarbon dates. At the same site, IYA3 and IYA5 represent second-degree relatives, both males sharing paternal lineage but different maternal lines, suggesting they were half-brothers, uncle and nephew, or first cousins. These patterns indicate that people were buried alongside close kin, transforming coastal cemeteries into family resting places.
Small Populations and Genetic Isolation
The genetic analysis reveals that Chono communities lived in small, isolated populations characterized by frequent marriages between relatives across many generations. Long stretches of homozygous DNA indicate that parents were often closely related, a pattern that intensifies toward the southern extremes of Patagonia. This genetic signature reflects the environmental constraints of archipelago life, where small canoe-based groups had limited marriage partners within their sustainable range.
Genetic diversity among the Chono and their southern neighbors is notably low compared to populations further north, consistent with small, stable populations constrained by harsh environmental conditions. This pattern developed gradually over the last few thousand years, as mid-Holocene Patagonian populations show higher diversity levels similar to other South American groups.
Chono Ancestry in Regional Context
When placed within the broader South American genetic landscape, the Chono form a distinctive ancestry cluster within Patagonian populations. They are most closely related to the Kawésqar people immediately to their south, forming what researchers term a "western archipelago" cluster of maritime peoples. Further south, the Yagán, Haush, and Selk'nam around Tierra del Fuego represent a "far south" cluster, subdivided between primarily seafaring and more terrestrial groups.
The Chono genomes show purely Indigenous South American ancestry without the mixed European and African signatures seen in many modern populations following 16th-century colonization. They occupy a critical position in Patagonian population structure, representing the northernmost extension of the highly drifted, small-population maritime ancestry characteristic of the far south.
Preserving Lost Histories
The genetic reconstruction of Chono population history serves as both scientific achievement and historical recovery. These ancient genomes provide one of the few direct windows into a culture so thoroughly erased by colonization that no organized descendant group claims their identity today. The combination of paleogenomics, archaeology, and ethnohistory has recovered crucial elements of their story: their distinctive ancestry within Patagonian populations, their complex family structures and social organization, their role as cultural intermediaries between southern sea nomads and northern Mapuche worlds, and the quiet persistence of their genetic heritage in modern Chiloé populations.
Comments