I ran the F4 ratio estimation program from ADMIXTOOLS on the HGDP Amerindian populations to see how the results would compare with those from ADMIXTURE and DIYDodecad.
Referring to the phylogeny for F4 ratio estimation below, I used San for the O population, Dai for the C population, Orcadians for the B population, Sardinians for the A population, and Amerindians for the X populations.
The results are below. The Nordic admixture proportions are in the alpha column, and are expressed as fractions of 1, not as percentages.
alpha std. err Z (null=0) Karitiana 0.182781 0.021297 8.583 Surui 0.211791 0.023151 9.148 Colombian 0.157253 0.020357 7.725 Maya 0.204853 0.016572 12.362 Pima 0.186089 0.019864 9.368
For comparison, here are the Nordic admixture percentages from the K = 17 admixture analysis of Amerindians:
Surui Colombian Maya Karitiana Pima Nordic 12.14 14.11 18.98 12.16 14.37
And here are the Nordic admixture percentages from the K = 16 admixture analysis of Mongoloids:
Yakut Karitiana Pima Surui Colombian Maya Uygur Hazara Nordic 12.51 15.96 17.71 16.48 16.74 21.90 16.70 15.37
There is good general agreement between all three analyses. They all put the Nordic admixture of the Amerindian populations in the 10 to 20 percent range.
Substituting Yoruba for San, Han for Dai, or Russians for Orcadians in the F4 ratio estimation does not significantly change the results.