A paper published in 2022 (Campelo dos Santos Andre Luiz, Owings Amanda, Sullasi Henry Socrates Lavalle, Gokcumen Omer, DeGiorgio Michael and Lindo John (2022). Genomic evidence for ancient human migration routes along South America's Atlantic coast. Proc. R. Soc. B.28920221078 http://doi.org/10.1098/rspb.2022.1078) reported the genomes of two ancient paleoindians from Northeastern Brazil, on the Atlantic coastal region and placed them in the context of other South American specimens.
The authors report that "...we also detect greater Denisovan than Neanderthal ancestry in ancient Uruguay and Panama individuals. Moreover, we find a strong Australasian signal in an ancient genome from Panama".
Australasian signal
The paper indicates that "A strong signal of Australasian ancestry, previously reported only for the Lagoa Santa individual and present-day Surui, was also observed for the previously published PAPV173, from Panama. The Piapoco, Surui and Karitiana, however, harbour high affinities with Brazil-2 and thus may have received contributions coming from Central America (in the form of the Australasian signal, in a north-to-south directionality) and South America's Atlantic coast (in a south-to-north directionality)."
The PAPV173 individual from Panama also harbored a very high proportion of Denisovan genes (see map below) while in the rest of South America the opposite is true: they have a higher proportion of Neanderthal to Denisovan ancestry. Why?
In the map below, the "Pie chart radius reflects the proportion of shared archaic loci in the individual."
An article pulbished on the Florida Atlantic University news site (some of the authors are researchers at the FAU) includes some comments by the authors
"“There is an entire Pacific Ocean between Australasia and the Americas, and we still don’t know how these ancestral genomic signals appeared in Central and South America without leaving traces in North America,” said Andre Luiz Campelo dos Santos, Ph.D., first author, an archaeologist and a postdoctoral fellow in FAU’s Department of Electrical Engineering and Computer Science.
To further add to the existing complexity, researchers also detected greater Denisovan than Neanderthal ancestry in ancient Uruguay and Panama individuals. Denisovans are a group of extinct humans first identified from DNA sequences from the tip of finger bone discovered around 2008.
“It’s phenomenal that Denisovan ancestry made it all the way to South America,” says John Lindo, Ph.D., a co-corresponding author of the article who specializes in ancient DNA analysis and is an assistant professor in the Department of Anthropology at Emory University. “The admixture must have occurred a long time before, perhaps 40,000 years ago. The fact that the Denisovan lineage persisted and its genetic signal made it into an ancient individual from Uruguay that is only 1,500 years old suggests that it was a large admixture event between a population of humans and Denisovans.”"
Unanswered questions
Is the Australasian signal an artifact of the models and computer analysis programs? Does the Denisovan genetic content indicate a link to Austronesians? (There is a high Denisovan content among people in that region). Why do the ancient South American natives have a higher proportion of Neanderthal than Denisovan content?
A recent paper published on Oct. 20, 2025 (An early East Asian lineage with unexpectedly low Denisovan ancestry, Yang, Jiaqi et al., Current Biology, Volume 35, Issue 20, 4898 - 4908.e4) found that the 40,000 year-old Tianyuan had the highest Denisovan genetic admixture among ancient Asians: "Among individuals from continental Eurasia, we find the highest proportion of detectable Denisovan ancestry in Tianyuan (∼0.25%), while other pre-LGM individuals from Eastern Eurasia had lower levels of Denisovan ancestry, comparable to those of later East Asians and Siberians."
It also noted that the Laos Hoabinhian hunter-gatherers also have high levels of Denisovan admixture "we found more Denisovan ancestry in the Hoabinhian individual La36846 than in the Jomon individuals, with the Hoabinhian individual carrying more segments covering a larger part of the genome." However, they report that "our results support the existence of a deep modern human lineage in East Asia with limited, if any, Denisovan ancestry, suggesting that at least one early East Asian lineage was not in contact, or in limited contact, with Denisovans. This implies different dispersals for modern humans into East Asia and suggests that Denisovans were sparsely distributed in the region."
The Panama sample PAPV173 is only 520-650 years BP yet it still carries a very high Denisovan signal, could this link it to the ancient Tianyuan man? The other South Americans have a lower signal, perhaps diluted by admixture with other groups of Asians who arrived later and had the limited contact suggested by Yang's paper?
Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2025by Austin Whittall ©
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