Ancient people of North America’s Clovis culture migrated to South America roughly 11,000 years ago, then mysteriously vanished, researchers have discovered.

In a new study, researchers analyzed DNA from 49 people living over a span of 10,000 years in Belize, Brazil, the Central Andes and southern South America. They found some of these people were genetically linked to people of the Clovis culture, one of the earliest archaeological cultures to extend throughout North America. Although archaeologists have suspected that Clovis people migrated south, they haven’t yet found any Clovis artifacts in South America.

This visual abstract depicts insights into the peopling of the Americas, including four southward migration events and notable population continuity in much of South America after arrival.

“We weren't expecting to find a relation to people associated with the Clovis culture in South America,” said Nathan Nakatsuka, a PhD student at Harvard Medical School who co-authored the new study published in Cell, in a Cell press release. “But it seems the expansion of the Clovis-associated lineage extended to parts of Central and South America.”

The researchers discovered that all 49 people in the study were descended from the migrants who crossed the Bering Strait into North America more than 15,000 years ago. Genetic distinctions between the people showed they’d traveled south in at least three different migration groups, one of which was the previously undocumented Clovis group.

In addition to discovering Clovis people in South America, researchers also found that these people disappeared from the continent about 9,000 years ago, and were replaced by people with different genetic ancestry. We don’t yet know why this happened, but the insight means archaeologists can start investigating.

“The large-scale population replacement is a process that was not widely expected by archaeologists,” said David Reich, a geneticist at Harvard Medical School and the Howard Hughes Medical Institute who co-authored the study, in the Cell press release. “This is an exciting example of how ancient DNA studies can reveal events in the past that were not confirmed and thus can stimulate new work in archaeology.”

Cell published the study the same week that Science published two other major studies about early people in the Americas. One of these identified the origins of Nevada’s 10,600-year-old “Spirit Cave Mummy.”