In the nineteenth century, the Mound Builder Myth — the idea that the earthen mounds of North America had been built by a now-vanished race rather than by the ancestors of contemporary Native Americans — served to sever the connection between Native people and the archaeological evidence of sophisticated pre-contact civilization, making it easier to justify the dispossession of Native lands.

More recent versions of similar arguments — the Solutrean hypothesis, which proposed that Ice Age Europeans rather than Asians were the first Americans, or various claims about pre-Columbian contact — have sometimes been deployed in ways that serve similar ends, undermining the specific historical connections between Native Americans and their ancestral lands and cultures.

Population Y is not in this category — it is a genuine scientific finding that has been reported carefully by researchers who are aware of its potential for misinterpretation.

But the misinterpretations have occurred anyway, as evidenced by the headlines claiming that Australians were among the first Americans.