Haplogroup R1a (Y-DNA)
R-M420 (R1a) is a common Y DNA haplogroup in many parts of Eurasia. One sub-clade (branch) of R-M420, R-M17 (R1a1a), is much more common than the others in all major geographical regions. R-M17, defined by the SNP mutation M17, (and sometimes alternatively defined as R-M198), is particularly common in a large region extending from South Asia and Southern Siberia to Central Europe and Scandinavia.(Underhill 2009)
The R-M420 family is defined most broadly by the SNP mutation M420, which was discovered after M17. The discovery of M420 resulted in a reorganization of the lineage in particular establishing a new paragroup (designated R-M420*) for the relatively rare lineages which are not in the R-SRY10831.2 (R1a1) branch leading to R-M17.
R-M420 and R-M17 are believed to have originated somewhere within Eurasia, most likely in the area from Eastern Europe to South Asia inclusive (see R-M17 for details on proposed origins).