The genetic sequencing company 23andMe recently tapped into its vast bank of data to release a study on genetic origins, producing the biggest genetic profile of the United States ever conducted—big, but nowhere near complete.

Out of more than 160,000 genomes, only 3 percent of 23andMe customers who authorized their data for the study were black, compared with the approximately 14 percent of the United States population who identifies as such. And while the paper traced what percent of white, black, and Latino customers’ ancestry led back to Native Americans, there were no users, as far as the paper reported, who self-identified as native people.

There are a lot of reasons for this. The service isn’t free, and not everyone wants—or can afford—to shell out $99 to learn about their ancestry. But when it comes to Native Americans, the question of genetic testing, and particularly genetic testing to determine ancestral origins, is controversial.

In the past decade, questions of how a person's genetic material gets used have become more and more common. Researchers and ethicists are still figuring how how to balance scientific goals with the need to respect individual and cultural privacy. And for Native Americans, the question of how to do that, like nearly everything, is bound up in a long history of racism and colonialism.

In many ways, the concerns that Native Americans have with genetic testing are the ones most people have: Who will be using this data, and for what?

Today, DNA can tell us a little about a lot of things, from disease risks to ancestral history. But ultimately it’s pretty limited. In fact, 23andMe was recently chastised by the FDA, which claimed the company was overselling the predictive power of their test for medical use. But in the future, that same little sample of DNA could be used for purposes that haven't even been dreamed up yet. People might be okay with their DNA being used to research cures for cancer, or to explore their own genetic history, but balk at it being used to develop biological weapons or justify genocide.

These are questions that anyone who gives their genetic material to scientists has to think about. And for Native Americans, who have witnessed their artifacts, remains, and land taken away, shared, and discussed among academics for centuries, concerns about genetic appropriation carry ominous reminders about the past. “I might trust this guy, but 100 years from now who is going to get the information? What are people going to do with that information? How can they twist it? Because that’s one thing that seems to happen a lot,” says Nick Tipon, the vice-chairman of the Sacred Sites Committee of the Federated Indians of Graton Rancheria, an organization that represents people of Coast Miwok and Southern Pomo descent.