When Spanish priests arrived in what is now California almost 250 years ago, they established a string of missions stretching from San Diego to the hills north of San Francisco—all built by forced Indigenous labor. Tens of thousands of Native Americans died from disease, malnourishment, and maltreatment during the mission period, which lasted until the 1830s.

By then, California’s Indigenous population had been devastated—including the Ohlone, or Costanoan, people, whose lands once included much of the San Francisco Bay Area. More than 8000 Ohlone perished between 1776 and 1833; from a precolonization population of approximately 30,000, there were fewer than 100 Ohlone left by the 1920s.

In the century that followed, the tribe was written off as vanished. In 1925, University of California, Berkeley, anthropologist Alfred Kroeber wrote that the Ohlone were “extinct for all practical purposes.”

But the Ohlone survived. Today, the tribe has about 500 members. Since 1989, they have been fighting for federal recognition, using genealogy to trace their family histories back to the Spanish mission period and legal documentation to show a long history of tribal presence in the Bay Area.

Now, they’re getting help from genetics. In a new study, researchers have used ancient DNA from two archaeological excavations to identify the Ohlone’s genetic signature and link ancient individuals, some buried nearly 2000 years ago, to their modern-day descendants. “This is fascinating work,” University of Kansas, Lawrence, paleogeneticist Jennifer Raff, who studies the early peopling of the Americas, wrote in an email. “If other tribes are interested in using genetics to investigate histories, they may be encouraged by the fact…