She described it as a “complete exchange of the population” in the area around Bogotá, based on the genetic evidence available.

Andrea Casas-Vargas, the Colombian co-author, noted that the group “might have died out because of climate conditions, disease, or lack of food,” while acknowledging that these are speculative possibilities rather than documented causes.

The researchers are clear in the paper itself that the replacement mechanism is not established by their data.

The study documents that genetic replacement occurred.

It does not identify a cause.

What the study does establish is the direction of the incoming ancestry — and this is one of the paper’s most significant findings.