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Major update reorganizes entire haplogroup I2 tree

Monday, March 7, 2016

I-S21825 draft tree

What is I-S21825? It is all of I-P37 except I-M26 and I-M423. That means I-S21825 includes the rare I-L233 "Western" branch and the much rarer I-Y11949 "Alpine", I-L1294 "France", and I-L880 "Northern France" branches

Here is a simple tree showing the major groups of I-P37
    |         \I-S21825
    |       /I-L621

Note:  P37, M26, S21825, M423, L621 and L161 each have dozens of equivalent SNPs, but CTS595 is the only known SNP at its level. Therefore I-P37 split into three branches almost simultaneously (into the I-M26, I-S21825 and I-M423 branches).

And here is the new I-S21825 draft tree:
 If you can't see the tree above easily, click here to download a pdf version of the tree.


  1. Thanks, DNA of I2a-haplogroup is so interesting because of so wide spread. If S21825 is about "Western/Alpine/France/NorthFrance" can we assume that it;s in overall about "WesternCentralEuropean" I2a ancestry ?
    If it's 18500 ybp, so what history background could define/explain such branching/divisioning from I-P37 ?

    How new branch is relevant to Alpine mentioned neighbor hg M436 => L38?

    If I-P37 are kinda-brother to I-M436, then I-CTS595 and I-L38 are Alpine-kinda-cousins? I know it's silly statement, but is the logic correct?

    On my blog, I collect old version of migration of I-P37 made by Ken:

    Is there any new version? Is Ken working on this area still?

  2. The reason that we talk about I-P37 instead of a more specific group like I-S21825 or a bigger group like I-L460 is simply because the P37 SNP was discovered very early, in the 1990s I think. And probably the reason P37 was one of the first SNPs to be discovered is because the Dinaric group is very common in Eastern Europe and a Dinaric man's Y chromosome was partially sequenced in an early study, and the M26 group is very common in Sardinia and a Sardinian man's Y chromosome was partly sequenced very early. And if you look at the mini tree above, the group that contains the Dinaric man and the Sardinian man is called I-P37. So P37 was known from very early on. But really there is not much shared history between M26 and the L621 group which includes Dinaric. These are all just ancient branches of haplogroup I that have been in Europe for thousands of years, some had localized population expansions 4000+ years ago such as when M26 arrived in Sardinia, others like Dinaric had big expansions much more recently. But when Dinaric was expanding it was nowhere near the M26 people, and probably nowhere near closer relatives like L161. So it doesn't make much sense to me to talk about P37 as a historical group. And if you are talking about very ancient Europe, things that happened 8,000+ years ago you should include the other European branches of hg I like I-M223 and the ancestors of I1, I-L38 etc.