As FTDNA I2a (I-P37.2) Project co-administrator I get some questions from our members, and I have decided to start posting some of the questions and answers to the hg I group for your comments etc..--Bernie Question: "I was wondering about one thing. I found this map: http://www.eupedia.com/europe/origins_haplogroups_europe.shtml#I2 It shows a large concentration of I2a in the area of Bosnia/Herzegovina, Croatia. I take it that my brother's I2a1 subgroup started in western Europe but was perhaps part of a larger group from the above area before that?" My answer: About the large Dinaric I2a2 group in central and eastern Europe: there are several groups of I2a and none of them are the ancestors of the other, and none is really a subset of the other. (When we get to more recent times and more specific haplogroups like I2a1b1a that kind of thinking makes more sense). Until very recently, human populations were very small and most paternal lines died out. 5,000 years ago our I-M26 paternal ancestors were already expanding in population size and were spread around westernmost Europe, we know this because of the skeletons in the Treilles cave and also because there are different groups of I-M26 with different 67 marker STR patterns with different geographic distributions. But 5,000 years ago, there was no Dinaric I2a2 group, they didn't start their population expansion until about 2,500 years ago. Before that we don't know where they were or how numerous they were because they didn't leave any traces, they left only one surviving male line from 5,000+ plus years ago to about 2,500 years ago. Sometime after around 2,500 years ago, the Dinaric people became associated with the Slavic tribes (or some other group which later became absorbed by the Slavic and other peoples) and expanded all over not just Bosnia but all of Eastern Europe and beyond. So after 2,500 years ago we can make theories about where the homeland of the I2a2 Dinaric people was, how long ago they made their migrations etc But my main point is that the I2a1 (I-M26) people were already a relatively thriving population in places like Spain and France before the I2a2 people in Bosnia etc. had their big boom. So we didn't necessarily come from there. See this post by haplogroup I expert Ken Nordtvedt. http://archiver.rootsweb.ancestry.com/th/read/Y-DNA-HAPLOGROUP-I/2011-12/1325371169 He mentions 11 main branches of haplogroup I and none are the ancestors of each other. We might be able to draw a tree showing the branching of the 11 different groups, but back when the groups had common ancestors, the groups didn't exist as we know them today. (But it might be correct to say that some British I2a1 group is the descendant of some French I2a1 group, because back when the British and French groups had a common ancestor the French group was already thriving and has continued in France until the present day). That's a good mailing list to read or subscribe to if you are interested in haplogroup I, you can also try dna-forums.org and I have heard of a DNA-Newbie mailing list although I haven't looked at it in a long time. Also see my trees here (check for my other blog posts too): http://cullengene.blogspot.com/2010/08/updated-haplogroup-i2a-tree.html In my drawing, populations weren't steadily expanding until the green bushy part towards the more recent right side of the tree. Before that, only single paternal lines have survived until the present.