Researchers have used the available Amazonian genomic data to address these questions, with results that are, as yet, not definitive.

The data are consistent with multiple models, and additional ancient genomes from the Amazon region — a region where preservation conditions for ancient DNA are extremely challenging — would be needed to resolve the question more clearly.

The Genomic History of South American Diversity

The full story of how South American Indigenous genetic diversity came to be as it is today is one that researchers are only now beginning to reconstruct with the kind of resolution that the ancient DNA revolution makes possible.

The picture that is emerging is one of remarkable complexity — multiple founding lineages, subsequent differentiation, periods of expansion and contraction driven by environmental and demographic factors, and episodes of contact and gene flow between populations that were previously genetically distinct.