While the diseases most strongly associated with Native American population collapse are the Old World pathogens introduced by European contact after 1492, there is no reason to assume that pathogen exposure was previously unknown as a demographic force.

Novel diseases can spread through networks of human contact independently of colonialism.

Climate stress: The middle to late Holocene on the Bogotá Altiplano saw significant environmental changes, including volcanic activity that the research co-authors mentioned in discussions of the Checua population.

Volcanic eruptions can disrupt local food systems, forcing populations to relocate or change their subsistence strategies in ways that might favor incoming groups with different agricultural capabilities.

Kim-Louise Krettek, the study’s first author, stated in comments reported by news outlets that the genetic material of the Checua people disappeared completely from what the team could detect in individuals from the region around 2,000 years old.