First, I looked at the correlation between the frequencies of occurrence of different haplogroups, limiting myself to haplogroups E3b1, I1a, I1b, J2, N2, N3, R1a, R1b3. For each haplogroup, I report the correlations which are at least 0.5 in absolute value (either positive or negative).
I1a: -0.56 with R1a
I1b: -0.76 with N3, -0.66 with N2
N2: -0.66 with I1b
N3: -0.76 with I1b, -0.66 with R1a
R1a: -0.66 with N3, -0.54 with I1a
The main points of interest are:
- I1a vs. R1a
- I1b vs. N3/N2
- R1a vs. N3
Longitude (west-to-east): R1a (-0.51), N2 (+0.56)
Latitude (south-to-north): I1b (-0.87), R1a (-0.57), N2 (+0.61), N3 (+0.79)
These observations suggest that the most striking features of the Russian Y-DNA landscape are the contrast between southern haplogroup I1b, and southwestern haplogroup R1a on the one hand, and northern haplogroup N3, and northeastern haplogroup N2 on the other. Thus, as a first-order approximation, the title of the paper, "Two Sources of the Russian Patrilineal Heritage in Their Eurasian Context" is justified, the two sources being R1a/I1b dominated SW/S group, and the other being N2/N3 dominated NE/N group.
Within the SW/S group, there is some concordance between the frequencies of haplogroups R1a and I1b, with a correlation of +0.40. Similarly, for the NE/N group, the correlation between N3 and N2 is +0.47. This suggests the pre-existence of these two combinations, while leaving open the possibility that a two-source solution is not the whole story.