I don't intend this list to fully describe the distribution, SNPs, and age of the various branches. You can see more information by clicking here to go to the Eupedia page for I2.
Here is an easy way to determine the position of a SNP:
Go to the YFull tree at https://www.yfull.com/tree/
Click Search at upper right, and enter the SNP, for example S2703
You will see a green box at right which lists the relevant tree for this SNP, or an equivalent SNP, for example I-Y3749
Click on the green box and you will see the tree. Look at the top and you will see that I-Y3749 is part of I-L1498, which is part of I-S2639, which is part of I-L161.1 etc.
Of course, not all SNPs will be found in YFull's tree.
I-P37 is a major haplogroup found throughout Europe. It reaches a maximum in Sardinia and in Bosnia and Herzegovina, and it's common throughout eastern and central Europe. It's also relatively common in Spain, Portugal and France.
Click here for our I-P37 orientation tree.
Formerly I-P37 was known as I-P37.2 because the P37 mutation occurs in haplogroup D (this was called P37.1) and in halogroup I (this was called P37.2).
For many years, only four SNPs were known in the I-P37.2 haplogroup: P37.2, M26, M161 and P41.2/M359.2. Two of these SNPs are important, P37 of course, and I-M26 is the branch common in Sardinia but also found in Iberia and throughout western Europe. The other SNPs are very rare and not very important: I-M161 is a very small part of I-M26 and I-P41.2/I-M359.2 is apparently part of I-CTS10228.
Because I-P37 is a very old group, several major branches could be identified by STR marker patterns. The four largest groups and their key marker values are:
"Dinaric" nicknamed after the Dinaric Alps in Bosnia and Herzgovina and Croatia. We now know that this group is equivalent to I-CTS10228. Dinaric has DYS385=14-15 or similar and DYS565=9
"Sardinian" which is characterized by YCA=11-21 or similar, this is equivalent to I-M26 (to be exact, the group with YCA=11-21 is equivalent to the more specific I-PF3981 haplogroup)
"Isles" which is equivalent to I-L161, easy to identify but no single distinctive marker value
"Western" which is equivalent to I-L233, has distinctive DYS388=15
All of these groups were well known from STR markers before any SNPs were discovered to define these groups. (except for M26 which was already known).
Some smaller groups were also identified by STR patterns.
"Disles" this group has markers very similar to Dinaric, but it lacks the distinctive value DYS565=9. Disles has DYS565=11 which is the common value for haplogroup I as a whole. We now consider Disles to be the group that is L621+ but CTS10228-
"I2a*-France" is now known as I-L1294 "France". Has distinctive DYS388=9.
"Alpine", now known as I-Y11949, it's closely related to I-L233 "Western".
"Northern France", now known as I-L880
and finally a major new group was discovered in 2017, called I-Y11949. It's M423+ but L621- and L161-. This group doesn't have a nickname and it's not shown on any tree on this blog. It's found in northern Spain and Portugal/the Azores.
I-A17273 is part of the I-M26 haplogroup, more specifically it's part of I-L160 and I-PF4088. I-A17273 includes men from Switzerland and Iberia, and it includes the large I-A19395 branch which is characterized by the STR marker value DYS450=9. The I-A19395 branch is found in Great Britain and Ireland, and also in northern parts of Germany, and even in Baltic areas where I-M26 is very rare (Germans from northern Poland, and people from Sweden and Finland).
I-A2330 is part of the I-L161 haplogroup, more specifically it's part of I-S2742, which is part of I-S2703. I-A2330 includes English men, but also men with ancestry from Germany, Norway etc. It's a small haplogroup.
I-A8462 is one of two fundamental branches of I-L233 "Western". At this point, all known I-A8462 members have paternal ancestry from Great Britain.
I-A8742 is part of the I-L161 haplogroup, more specifically it's part of I-A1150 which is part of I-L1498. The most recent common ancestor of I-A8742 lived approximately 6400 years old according to YFull's calculation. But it's a small haplogroup, and all known I-A8742 members have paternal origin from Great Britain and France.
I-CTS10228 is the very large haplogroup that is nicknamed "Dinaric".
I-CTS11338 is part of the I-M26 "Sardinian" haplogroup. More specifically, I-CTS11338 is part of I-L160. I-CTS11338 contains the large I-PF4190 branch which is very common in Sardinia, and the large I-Z102 branch which is found in Spain, Portugal and France (and also in England and very low levels). I-CTS11338 also contains several small branches.
I-F1295 is part of the I-M26 "Sardinian" haplogroup. Most I-M26 men belong to the well known I-L160 haplogroup, and all known I-L160 men belong to either the large I-PF4088 haplogroup or the much smaller I-F1295 haplogroup.
I-F1295 contains three fundamental branches:
- one small branch from England
- one small branch that contains a single French-Canadian family
- the large I-PF6950 branch which contains men from Greece, Italy, Sardinia, Spain, the Azores, Ireland and Germany. I-PF6950 also contains a cluster of men with Eastern European (Ashkenazi) Jewish ancestry, one of these families claims earlier Spanish (Sephardic) origin. This cluster is the only known Jewish branch in I-M26.
I-FT11343 is part of the I-L233 "Western" haplogroup, more specifically it's part of I-A8462. All known I-FT11343 men belong to the Lindsay/Lindsey/Lindesay family from Scotland, or they belong to downstream branches and very likely have a Lindsay paternal ancestor at some point in the past.
I-L160 is part of the I-M26 "Sardinian" haplogroup. Most I-M26 men belong to the well known I-L160 haplogroup, and all known I-L160 men belong to either the large I-PF4088 haplogroup or the much smaller I-F1295 haplogroup.
I-L161 has been nicknamed "Isles", it's one of the major branches of I-P37. But there are two fundamental branches of I-L161, and the I-Y13338 branch has been found only in continental Europe (Poland, Germany, Bulgaria) and also in Iran.
I-L1294 was formerly called I-P37.2 "France", it's part of the I-S21825 haplogroup. All known I-L1294 results at FTDNA have ancestry from Britain, France or Germany, and there is one man from Spain. But the I-L1294 haplogroup is easily identified by the distinctive STR marker value DYS388=9, in combination with other marker values. We know from scientific studies that I-L1294 is somewhat common in France, and in Catalonia, Spain, and it has also been found in Albania. This is a good illustration of the northwestern European bias of the FTDNA database, and a good illustration that there is still much to learn about haplogroups even in Western Europe.
I-L233 is one of the major branches of I-P37, it's nicknamed "Western" because it's usually found in Western Europe: Great Britain, the Netherlands, northwestern Germany, Denmark. But it's also found in Poland, Moldova, Croatia, Albania etc.
I-L621 is one of the major branches of I-P37. I-L621 contains the very large I-CTS10228 Dinaric haplogroup which reaches a maximum in Bosnia and Herzegovina and which is common throughout Eastern and Central Europe. I-L621 also contains several small branches known as "Disles", these branches are especially common in Great Britain and Ireland but they also have been found in Germany, Poland and Sweden.
I-PH908 is part of the I-CTS10228 "Dinaric" haplogroup. I-PH908 is exactly the same as the Dinaric South cluster: this is the group of Dinarics with DYS448=19 and usually DYS449=30 or some other low value.
I-S21825 contains the several small haplogroups. The largest is I-L233 "Western". I-S21825 also contains the I-Y11949 "Alpine" group which is closely related to I-L233, and the I-L880 "Northern France, and the I-L1294 "France" haplogroups.
I-S17250 is part of the I-CTS10228 "Dinaric" haplogroup. The I-S17250 branch is the most numerous branch below I-CTS10228, it prevails in Central Europe (Poland, Hungary, Germany, Slovakia, Czech Republic, part of Ukraine) and Southeastern Europe. This haplogroup encompasses a part of the Dinaric North cluster and the whole Dinaric South cluster.
I-S2703 is part of the I-L161 "Isles" haplogroup. I-S2703 contains the Irish/British I-Y3723 haplogroup (shown in another tree) and the I-S2472 haplogroup which is a complicated group that is found in Britain and Ireland, but also in Germany, Poland and Sweden.
I-Y11222 is part of the I-M26 "Sardinian" haplogroup. I-Y11222 is a parallel branch to the much larger I-L160 haplogroup. I-Y11222 is maybe more typical of northern Europe (Ireland, Britain, Germany) and I-L160 is maybe more typical of southern Europe (Iberia, Italy, Sardinia) but both haplogroups are found in all of these areas.
I-Y12072 is nicknamed "Isles-A", it's part of I-L161. I-Y12072 contains a few rare branches but most I-Y12072 men belong to the large I-PF4135 haplogroup which expanded out of County Cork, Ireland over 1500 years ago. I-PF4135 is now found in Scotland, England, the Isle of Man and Ireland.
I-Y14612 is part of the I-L161 haplogroup, more specifically it's part of I-S2742, which is part of I-S2703. The I-Y14612 haplogroup contains the IsleS-B1 cluster and related branches, these are mostly from England and Sweden. In my opinion there's not a major distinction between I-Y14612 and other branches of I-S2742, we created the I-Y14612 tree because our I-S2703 tree was too large.
I-Y18331 shown on our I-CTS10228 tree. I-Y18331 is found in Greece and in the Jewish diaspora cluster.
I-Y3723 is part of the I-L161 haplogroup. I-Y3723 is almost exclusively found in Britain and Ireland, and it contains the large Isles-C and Isles-D branches. Many of these branches are especially characteristic of central-western Ireland, some branches are more typical of Scotland.
I-Y4252 is contains almost everyone in the I-L233 "Western" haplogroup. According to the FTDNA tree, I-Y4252 contains 26 immediate child branches, 15 of these branches are named and 11 are unnamed I-Y4252* branches that contain only a single member at present. (These numbers are as of April 2020 and they will change in the future). Most of the named branches contain representatives from Great Britain and Ireland and also from Continental Europe/Scandinavia. Our I-Y4252 draft tree groups some of the branches into the larger I-FGC56883 branch. FGC56883 occurs in a palindrome region and it won't be added to FTDNA and YFull's trees
I-Y4460 is part of the I-CTS10228 "Dinaric" haplogroup. The I-Y4460 haplogroup prevails in eastern and northeastern Europe (Russia, Belarus, Ukraine, Baltic countries etc.). All persons from this haplogroup are in the Dinaric North cluster.
I-Y4882 is part of the I-CTS10228 "Dinaric" haplogroup. All members of I-Y4882 belong to the Dinaric North cluster.
I-Y5455 is nicknamed "Isles-C", it's part of I-L161 and more specifically part of I-Y3723. Isles-C is especially characteristic of central-western Ireland.
I-Z113 is part of the I-M26 haplogroup, it's maybe the most common branch of I-M26 outside of Sardinia. The MRCA of I-Z113 lived approximately 1600 years ago, according to YFull's calculation. I-Z113 is found in Spain, Portugal, the Azores and France, and there are also a few I-Z113 men from England.
I-Z17855 is part of the I-CTS10228 "Dinaric" haplogroup. I-Z17855 can be found in mostly in Bulgaria, also in Serbia, Greece, Slovakia, Hungary and Ukraine etc. All persons in this haplogroup belong to the Dinaric North cluster.