individuals carried the M198 and M17 mutations except one individual in a sample of Iranians from Gilan (n=27), who was reported to belong to R1a-SRY1532.2(xM198, M17). found R1a1-SRY10831.2 in 20.8% (16/77) of a sample of Persians collected in the provinces of Khorasan and Kerman in eastern Iran, but they did not find any member of this haplogroup in a sample of 25 Kurds collected in the province of Kermanshah in western Iran. Further to the north of these Western Asian regions on the other hand, R1a1a levels start to increase in the Caucasus, once again in an uneven way. Several populations studied have shown no sign of R1a1a, while highest levels so far discovered in the region appears to belong to speakers of the Karachay-Balkar language among whom about one quarter of men tested so far are in haplogroup R1a1a. Historic naming of R1a The historic naming system commonly used for R1a was inconsistent in different published sources, because it changed often; this requires some explanation. In 2002, the Y Chromosome Consortium (YCC) proposed a new naming system for haplogroups , which has now become standard. In this system, names with the format "R1" and "R1a" are "phylogenetic" names, aimed at marking positions in a family tree. Names of SNP mutations can also be used to name clades or haplogroups. For example, as M173 is currently the defining mutation of R1, R1 is also R-M173, a "mutational" clade name. When a new branching in a tree is discovered, some phylogenetic names will change, but by definition all mutational names will remain the same. The widely occurring haplogroup defined by mutation M17 was known by various names, such as "Eu19", as used in in the older naming systems. The 2002 YCC proposal assigned the name R1a to the haplogroup defined by mutation SRY1532.2. This included Eu19 (i.e. R-M17) as a subclade, so Eu19 was named R1a1. Note, SRY1532.2 is also known as SRY10831.2 The discovery of M420 in 2009 has caused a reassignment of these phylogenetic names.( and ) R1a is now defined by the M420 mutation: in this updated tree, the subclade defined by SRY1532.2 has moved from R1a to R1a1, and Eu19 (R-M17) from R1a1 to R1a1a. More recent updates recorded at the ISOGG reference webpage involve branches of R-M17, including one major branch, R-M417. See also Y-DNA R-M207 subclades Y-DNA backbone tree Notes References Sources also at Further