Over the years, a few of my posts have been surprisingly popular–Turkey: Not very Turkic, Why do Native Americans Have so much Neanderthal DNA?, Do Black Babies have Blue Eyes? and Can Ice packs help stop a seizure (in humans)?
It’s been a while since these posts aired, so I thought it was time to revisit the material and see if anything new has turned up.
Today, lets revisit Native Americans and Neanderthal DNA:
I’m sorry, but I no longer think Native Americans (aka American Indians) have higher than usual levels of Neanderthal DNA. Sorry. Their Neanderthal DNA levels are similar to (but slightly lower than) those of other members of the Greater Asian Clade. They also have a small amount of Denisovan DNA–at least some of them.
Why the confusion? Some Neanderthal-derived alleles are indeed more common in Native Americans than in other peoples. For example, the Neanderthal derived allele SLC16A11 occurs in 10% of sampled Chinese, 0% of Europeans, and 50% of sampled Native Americans. (Today, this gene makes people susceptible to Type 2 diabetes, but it must have been very useful to past people to be found in such a large percent of the population.)
And there was one anomalously high Neanderthal DNA measure in Natives living near the Great Slave Lake, Canada. (Look, I didn’t name the lake.)
But this doesn’t mean all Native Americans possess all Neanderthal alleles in greater quantities.
So how much Neanderthal do Native Americans have? Of course, we can’t quite be sure, especially since only a few Neanderthals have even had their DNA analyzed, and with each new Neanderthal sequenced, we have more DNA available to compare against human genomes. But here are some estimates:
Sriram Sankararaman et al, in The Combined Landscape of Denisovan and Neanderthal Ancestry in Present-Day Humans, report:
Native Americans: 1.37%
Central Asia: 1.4%
East Asia: 1.39%
Oceana (Melanesians): 1.54%
South Asia: 1.19%
I have seen it claimed that the high Neanderthal percents for Oceanan populations (that is, Melanesians and their relatives,) could be a result of Denisovan DNA being incompletely distinguished from Neanderthal.
Prufer et al, [pdf] 2017, report somewhat higher values:
East Asians: 2.3–2.6%
While Lohse and Frantz estimate an even higher rate of between 3.4–7.3% for Europeans and East Asians. (They found 5.9% in their Chinese sample and 5.3% in their European.)
I found an older paper by Prufer et al with estimates for three Hispanic populations, but doesn’t clarify if they have Native American ancestry:
CLM–Colombians from Medellin: 1.14%
MXL–Mexicans in LA: 1.22%
PUR–Puerto Rico: 1.05%
Since this is an older paper, all of its estimates may be on the low side.
The absolute values of these numbers is probably less important than the overall ratios, since the numbers themselves are still changing as more Neanderthal DNA is uncovered. The ratios in different papers point to Native Americans having, overall, about the same amount of Neanderthal DNA as their relatives in East Asia.
Melanesians, though. There’s an interesting story lying in their DNA.