In reality, such testing does not tell us much about our ancestors. That’s partly because of the way DNA is passed down through the generations and partly because there exists no database of ancestral DNA. Instead, the companies compare your DNA to that of other contemporary humans who have paid them to take the test. Then they compare your particular variations to patterns of geographical and ethnic distribution of such variations in today’s world ― and use secret algorithms to assign purportedly precise ancestral percentages to them.
…These three political developments downplay Native American identity, sovereignty, and rights, while denying, implicitly or explicitly, that history created today’s realities of racial inequality. The use of DNA tests to claim “Native American” genes or blood trivializes this same history.