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Thread: Did haplogroup I only develop after the Ice Age?

  1. #11
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    Quote Originally Posted by epp View Post
    The man buried in the Swiss cave was not proven I2a - the researcher merely described I2a as his "best guess"..
    Not the researcher. The haplogroups were determined by Yfitter. The “maximum likelihood haplogroup” (12a in this case) is described by Yfitter as being the best guess haplogroup while the “confidence haplogroup” (I2 in this case) is described as the conservative guess haplogroup. This is Yfitter: http://arxiv.org/abs/1407.7988

    I doubt whether I2 would be seriously wrong.

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  3. #12
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    Quote Originally Posted by epp View Post
    Just to clarify, I'm not suggesting that haplogroup I originated in North West Europe, rather that North West Europe is the likely location for the most recent common ancestor of its surviving lineages.
    Yeah, that is what I mean as well.

    It would be quite surprising if no one had suggested North West Europe before, as the data freely available on the internet seems to indicate it fairly clearly - the most diverse I1 samples are found in this region, and the most diverse I2 samples are also found in this region.
    Honestly I don't know much about haplogroup I diversity. I find it very difficult to compare diversity of anything in Europe, especially Northwest Europe, to other parts of the world, simply because so much of what is known is from private testing, which is massively biased geographically and lacks information about frequency and representativeness. I mostly rely on academic studies for that reason, but of course that has limitations as well.

    I have never come across an I*(xI1, I2) in Northwestern Europe, but it exists in the Caucasus. And I have heard before that the greatest diversity of I1 is in Central Europe, though I wouldn't know myself. I would be interested to know where the most basal clades of I are to be found, actually.

  4. #13
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    Quote Originally Posted by epp View Post
    the most diverse I1 samples are found in this region, and the most diverse I2 samples are also found in this region.
    The TMRCA of all known living I1 is only 4700 years ago, according to YFull. In other words, one man living 4700 years ago patrilineally sired all the millions of I1 men living today. Because I1 expanded so rapidly at that time, both demographically and geographically, modern DNA results alone cannot possibly tell us where that one man lived.

    I2's haplotree presents a very different picture. One could plot the current locations of all its various branches in an attempt to guess the tracks of its demographic and geographic growth across the millennia. But even in this case, I think we need much more data--especially from the rare offshoots which often provide the best clues.

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    Quote Originally Posted by Megalophias View Post
    .

    I have never come across an I*(xI1, I2) in Northwestern Europe, but it exists in the Caucasus.
    I believe all the "" I*" previously found in the Caucasus is now known to be I2c- and one specific sub-branch of 3 otherwise found in Europe.

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    Quote Originally Posted by Jean M View Post
    Not the researcher. The haplogroups were determined by Yfitter. The “maximum likelihood haplogroup” (12a in this case) is described by Yfitter as being the best guess haplogroup while the “confidence haplogroup” (I2 in this case) is described as the conservative guess haplogroup. This is Yfitter: http://arxiv.org/abs/1407.7988

    I doubt whether I2 would be seriously wrong.
    Y SNP calls per Genetiker:
    https://genetiker.wordpress.com/y-sn...nter-gatherer/
    "The calls show that the Grotte du Bichon hunter-gatherer belonged to Y haplogroup pre-I2a1a2a1-L1287"

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  10. #16
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    Quote Originally Posted by Jean M View Post
    Geneticists used to claim that it was most diverse today in southeastern Europe, but in any case this methodology is problematic.

    Yes geneticists developed the theory that that where they find the greatest genetic variance of a haplogroup is likely to be its point of origin, since the longer a lineage has been in a place, the longer it has had to accumulate variations. This seems satisfactory in broad continental outline, but later movements will have swirled the mix in ways that could mislead us if we expect variance today to exactly match that in prehistory. A present-day population could have acquired diversity from diverse waves of immigrants. We find a high variance within European haplogroups in the United States of America, but we know full well that these haplogroups do not have their origin there. So variance is most convincing when supported by other kinds of evidence.

    Take archaeology. There was no-one living in Northern Europe when it was covered by ice sheets. So everyone living today in Scandinavia and the British Isles descends from people who arrived there in the Mesolithic at the earliest. (We now know that later migrations had a huge impact on the gene pool.) The pattern of diversity in Y-DNA I that we see in living people today cannot reflect an origin point in northern Europe before the LGM.

    I2 was present in Scandinavia in the Mesolithic, but not the I1 that is more common there today.
    I1 and I2 were both present in Neolithic Hungary.
    The expansion of I1 in Scandinavia is compatible with an arrival in the Copper/Bronze Age.
    The expansion of I2a1b2a in the Balkans is compatible with the arrival of Slavs in the early medieval period. There they might encounter the occasional I2a that descended from Neolithic farmers there, so creating diversity.
    Quote Originally Posted by Jean M View Post

    Yes geneticists developed the theory that that where they find the greatest genetic variance of a haplogroup is likely to be its point of origin, since the longer a lineage has been in a place, the longer it has had to accumulate variations. This seems satisfactory in broad continental outline, but later movements will have swirled the mix in ways that could mislead us if we expect variance today to exactly match that in prehistory. A present-day population could have acquired diversity from diverse waves of immigrants.
    Quote Originally Posted by Jean M View Post
    I2 was present in Scandinavia in the Mesolithic, but not the I1 that is more common there today.
    From thousands of samples published on the internet, these are the estimated points of origin for the most diverse haplogroup I subclades, based on their degree of internal diversity - I* (pre- I1) - Britain/Norway; I2 (pre- I2b/I2c) - Germany; I2a2 - Britain/Low Countries; I2a1b - Britain; I2a1a (pre-I2a1a1) - Britain/NW France; I2a1a2 - Germany.

    I am not saying that haplogroup I definitely originated in these areas, but merely ask - does this pattern indicate that these haplogroup I lineages are more likely to be ancestral to these areas where they are all now found, or ancestral to Southern Europe, the Caucasus, the Balkans or some other region not appearing anywhere at all in this mix?

    To me, the theory that these earliest subclades each evolved somewhere else, then all relocated to North West Europe "in diverse waves of immigration" without leaving a trace in any of their points of origin, seems less plausible than the theory that they evolved approximately in the region where they are now all found.

    This is simply based on DNA data, not on conjecture (such as 'conjectural maps'), nor on any uncertain premise, such as that I1 was "not present in Scandinavia in the Mesolithic" (we cannot know that).

    The Swiss sample previously mentioned suggests that there was an early haplogroup I individual (whose DNA was more similar to I2a than to other surviving lineages) living North West of the Alps not too long after the Ice Age. This does not seem at all inconsistent with the premise proposed in the thread.

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    Quote Originally Posted by epp View Post

    I am not saying that haplogroup I definitely originated in these areas, but merely ask - does this pattern indicate that these haplogroup I lineages are more likely to be ancestral to these areas where they are all now found, or ancestral to Southern Europe, the Caucasus, the Balkans or some other region not appearing anywhere at all in this mix?

    To me, the theory that these earliest subclades each evolved somewhere else, then all relocated to North West Europe "in diverse waves of immigration" without leaving a trace in any of their points of origin, seems less plausible than the theory that they evolved approximately in the region where they are now all found.

    This is simply based on DNA data, not on conjecture (such as 'conjectural maps'), nor on any uncertain premise, such as that I1 was "not present in Scandinavia in the Mesolithic" (we cannot know that).

    The Swiss sample previously mentioned suggests that there was an early haplogroup I individual (whose DNA was more similar to I2a than to other surviving lineages) living North West of the Alps not too long after the Ice Age. This does not seem at all inconsistent with the premise proposed in the thread.
    They cannot have 'originated' in NW EUrope, because when they did - NW Europe was under Ice.
    It might be the case that simply that they better survived in northern Europe than they did in the south. This isn't too difficult to fathom.

    The Bichon sample is believed to have been found within an Azilian context, which is post-Magdalenian, which spread from southern France.

    From thousands of samples published on the internet, these are the estimated points of origin for the most diverse haplogroup I subclades, based on their degree of internal diversity - I* (pre- I1) - Britain/Norway; I2 (pre- I2b/I2c) - Germany; I2a2 - Britain/Low Countries; I2a1b - Britain; I2a1a (pre-I2a1a1) - Britain/NW France; I2a1a2 - Germany.
    No genuine I* samples have been found - so you might be looking at old (outdated) data. And as Jean explained, looking at basal diversity is often wrong. Just look at previous ideas which placed R1b in Iberia, or Turkey becuase of supposed 'basal diversity'.
    You need to look at collateral evidence, aDNA, and properly resolved modern data.

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    Quote Originally Posted by Gravetto-Danubian View Post
    I believe all the "" I*" previously found in the Caucasus is now known to be I2c- and one specific sub-branch of 3 otherwise found in Europe.
    The recent study of Dagestan reports a Lak who is I-P19(xI1-P30, I2-P215). Di Cristofaro also found a Hazara with I-M258(xI1-M253, I2-M438) in Afghanistan, now that I check.

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    Quote Originally Posted by Gravetto-Danubian View Post
    They cannot have 'originated' in NW EUrope, because when they did - NW Europe was under Ice.
    The premise of the thread is that their most recent common ancestor might have lived after the Ice Age. I am looking at this period, not when NW Europe was under ice.

    Quote Originally Posted by Gravetto-Danubian View Post
    No genuine I* samples have been found - so you might be looking at old (outdated) data. And as Jean explained, looking at basal diversity is often wrong. Just look at previous ideas which placed R1b in Iberia, or Turkey becuase of supposed 'basal diversity'.
    You need to look at collateral evidence, aDNA, and properly resolved modern data.
    By I* (pre-I1) points of origin, I simply mean I1 samples whose ancestors would have been I* at the earliest stages of haplogroup I's development (as the I1 mutation seems to have occurred more recently than the I2 mutation).
    If, as you say, basal diversity is often wrong, this doesn't mean that it has to be wrong in this case. In fact, like any other source of evidence, basal diversity is going to be right more often than wrong. Since basal diversity predicts a similar outcome (NW European ancestry) over each of the six sub-groups identified above, it would have to be coincidentally wrong six-fold to be wrong in general (inherently implausible, unless there is other evidence to the contrary - my interest in starting this thread is to find out if there is any reliable evidence to the contrary).
    Why do you seem to imply that my underlying data (published by FTDNA) is not "properly resolved"? Is it because of misunderstanding what I meant by "I* (pre-I1)"?

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    Quote Originally Posted by epp View Post
    Why do you seem to mply that my underlying data (published by FTDNA) is not "properly resolved"? Is it because of misunderstanding what I meant by "I* (pre-I1)"?
    How much of your FTDNA data is from Northwestern Europe vs from anywhere else?

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