Denisovans seem to have provided Native Americans with genes that protected them from disease.
A paper published last August (Fernando A. Villanea et al. ,The MUC19 gene: An evolutionary history of recurrent introgression and natural selection. Science 389, eadl0882 (2025). DOI:10.1126/science.adl0882), suggests that Denisovans supplied Amerindians with genetic material that helped them adapt to their new environment when they reached America.
The authors report an introgression in some non-Africans, of "a mosaic region of archaic ancestry: a small Denisovan-like haplotype (72-kb) embedded in a larger Neanderthal haplotype (742-kb), that was inherited through Neanderthals who themselves acquired Denisovan ancestry from an earlier introgression event...
the [importance of the] gene MUC19... as a candidate to study adaptive introgression; one of the haplotypes that span this gene in modern humans is of archaic origin, as modern humans inherited this haplotype from Neanderthals who in turn inherited it from Denisovans, and the haplotype introduced nine missense mutations that are at high frequency in both Indigenous and admixed American populations. Individuals with the archaic haplotype carry a massive coding VNTR expansion relative to the nonarchaic haplotype and their functional differences may help explain how mainland Indigenous Americans adapted to their environments."
The authors explain that a 72-kb "Denisovan-like haplotype" was found in Neanderthals and modern humans (excluding Africans who didn't admix with Neanderthals as these never lived in that continent) and that it was nested within a "larger Neanderthal haplotype". So the Denisovans provided their bit of genetic materials to Neanderthals, and we inherited it, and also Neanderthal genetic material from the latter.
The interesting part is that the Altai Neanderthal (from central Asia) which is around 120,000 years old, "does not harbor the Denisovan-like haplotpe" (the 72-kb region) but those from Europe, the Chagyrskaya and Vindija Neanderthals carry it. These are younger (44 to 59,000 years old).
The lack of this haplotype in Neanderthals from Altai, led the authors to conclude that the Denisovans who carried this 72 kb-region "may not be closely related to Altai Denisovan" group. It was some other Densiovan population.
The study also found that within the "...in the core 72-kb region... some modern humans carry two Denisovan-specific synonymous mutations and nine Denisovan-specific nonsynonymous mutations." The nine Denisovan-specific missense variants are found in pre-Hispanic remains at frequencies that vary between 31.6% and 40.6%. That is, before Europeans (and their African slaves) reached America.
As expected, they are also found in admixed American populations (Amerindian plus other human groups) at frequencies that range between 6.9% and 30.5%, which is logical since the influx of Old World people into America must have diluted this ancient genetic component.
And, yes, it is much lower: 0.5% to 15.7% among modern European and South and East Asians.
Within the Mexican (MXL) group these nine mutations of Denisovan origin reach a 30.5% frequency! It is around 22% among Peruvians (PEL), 7% among Colombians (CLM), and 9% in Puerto Rico (PUR).
The paper also looked into Africans, analyzing 44 samples and only one of them turned up with the nine Denisovan mutations (a frequency below 1.1%). Clearly the Denisovans didn't admix inside Africa. Since this single case was a Khomani San individual, supposedly carrying ancient genes, and belonging to a population which diverged from the rest of mankind over 100,000 years ago (according to the Out of Africa theory) it is something that has to be explained.
This single San person carried all of the nine Denisovan missense variants. The authors explain this as follows "The sequence divergence between this San haplotype and the archaic MXL haplotype at the 72-kb region is high (0.001342), further supporting the origin of the archaic haplotype in non-Africans as introgressed... Finding a divergent haplotype in the San is consistent with a previous study, as ~1% of their ancestry can be attributed to lineages that diverged from the main human lineage more than 1 million years ago... Furthermore, we cannot determine whether this variant found its way into the San through modern admixture of non-African ancestry into Sub-Saharan populations." In other words, they got it from some ancestor of Denisovans or, through recent admixture with modern non-Africans. I tend to choose the latter.
Could it be possible that a band of Neanderthals reached America long ago, after trysting with Denisovans, and the later waves of Homo sapiens mingled with them, picked up their mutations?
It is also likely that after the "Great Dying" that wiped out 80 to 90% of Amerindians (European-borne diseases like flu, measles, smallpox, etc. in the early 1500s) those who survived were the ones carrying multiple VNTRs, that provided them with higher immunity.
The "Great Dying" is unique in modern history, and always ignored when studying Native American populations. It caused millions to die, and their genetic history is lost. Modern Americans with Amerindian genes don't carry those of the people who died then. It killed almost all of the Native Americans, altering the genetic makeup of those who survived. But this is, as I said above, ignored.
Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2025 by Austin Whittall ©
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