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bicicleur
13-06-15, 21:23
very little is known about I2b/I2c
very few subclades and SNPs are know
no acurate TMRCA dates
Haak et al mentions 2 I2c2 samples : Motola 2 , Sweden, 7700 year old mesolithic and Esperstedt 4 , Germany +/- 4000 year old Unetice EBA
present distrbution of I2b and I2c is very peculiar, it is both in Trancaucasia and parts of Europe (Central & west, not mediterranean)
eastern Epigravettian could explain this :
- it probably originated north of the Black Sea during LGM
- it reached eastern Carpathians (Moldavia & Roumania) some 9000 years ago
- it was in Transcaucasia 17-13000 years ago http://www.digitorient.com/wp/wp-content/uploads/2013/09/Montoya-et-al.-2013-JHE-in-press.pdf
the question remains then : how did it spread all over Europe, and how did it survive there while many other tribes got extinct? maybe picked up in IE expansion, but Motola 2 was there even before
what's your guess?

sparkey
14-06-15, 09:30
Obviously, this interests me greatly, but I don't have much time at the moment. I will say this before I get around to a more complete answer: the modern I2c in Asia and Eastern Europe is all of one rather young, downstream subclade.

bicicleur
14-06-15, 14:06
that's the clue, to find out how old the youngest subclade is that spread over both Europe and Transcaucasia
and how did they spread, east to west or viceversa
i didn't find any info on that
did you?

sparkey
15-06-15, 19:28
that's the clue, to find out how old the youngest subclade is that spread over both Europe and Transcaucasia
and how did they spread, east to west or viceversa
i didn't find any info on that
did you?

Well, here's the evidence we have. The first split on the L460- branch of I2 is I2b/I2c. I think Nordtvedt's tree is down, but IIRC he estimated this split at about 12,000YBP. I2b is much more rare, but seems to be most common in (northern?) Italy, with known presence in Scotland, Germany, and Iran.

The next split is between I2c1 (my haplogroup) and I2c2. IIRC Nordtvedt has this split around 8,000YBP. I2c1 seems to have diversified relatively soon after, and is now mostly Western and Central European, with a lot of diversity around Germany. I2c2 is the one that's in Eastern Europe and Asia, although it also has a presence in Western and Central Europe. I2c2's modern branches seem to be a bit younger, and its center of diversity is more difficult to place. Motala2, a Mesolithic Swede, tested as I2c2, as did Esperstedt4, a Unetice culture sample.

Beneath I2c2, we don't have a complete picture yet, but the oldest known SNP split (over BY2816) has West Asian representation on both sides, indicating that it's been in West Asia since near when its modern branches started diversifying. I don't recall when Nordtvedt estimated this diversification to have begun, but I don't think it was much more than 2,000 years ago, so we have to keep in mind that even though modern I2c2 may have relatively high diversity in West Asia, this diversification event seems to have happened a long time after we know it was already in Europe thanks to the ancient samples.

To me, all signs point to I2c2 being a once somewhat common European haplogroup that dwindled in Europe but had a bit of a revival in West Asia. Its modern branches all seem to be close in time to its explosion in West Asia, although it's not quite clear that all modern I2c2 was once in West Asia--I'd argue against it, due to the widespread European remnant distribution, but it's an interesting possibility.

One theory that I find interesting, if farfetched, is Hovann Simonian's theory that all I2c2 descends from the Bagratids (https://en.wikipedia.org/wiki/Bagratid_dynasties). If you have some time to watch a long lecture on that sort of theory, it's here: http://youtu.be/etBNo0638Pw

bicicleur
16-06-15, 14:56
FTDNA labels BY2816 as I2c2b and they have only 2 individuals from Transcaucasia (Georigia and Armenia) but none European
I2c1 seems exclusively European - not Transcaucasian,
while both I2c2* and I2c2a1 are represented in both Europe and Transcaucasia (no mention of I2c2a and no specific SNP is connected to I2c2a1)
very weird, as if multiple expansions into Europe must have happened (or vice versa from Europe to Transcaucasia)

the lecture is quite lengthy ; if you could tell me at what time Hovann Simonian talks about the Bagratids, I'll have a look

Kardu
21-06-15, 17:54
7319 from the last version of YFull experimental tree