Third, it provides direct genetic evidence for the linguistic and cultural expansion associated with the Chibchan language family, demonstrating that the spread of Chibchan languages into the northern Andes was accompanied by substantial genetic change — the movement of people, not merely the adoption of cultural innovations by existing populations.

Fourth, it raises fundamental questions about the demographic dynamics of northern South America between 6,000 and 2,000 years before present — a four-thousand-year period during which, the data suggest, a complete genetic turnover occurred on the Altiplano, but for which the specific causes and mechanisms remain unknown.

The Question Of What “Disappeared” Means

Any honest account of the Checua findings must grapple carefully with the language of disappearance.

The lineage, as the study’s authors note, “does not contribute genetically to ancient or present-day South American populations” — a finding that has been summarized in popular coverage as the ancestry having “disappeared,” “vanished,” or the population having “completely replaced.”