From: tgpedersen
Message: 59721
Date: 2008-08-01
>I can't find the subclades Ia and Ib in the reference you provided. Is
> tgpedersen wrote:
> > I suspect you have peeked in the folder of maps of Oppenheimer's
> > gene variants, and found the I (Ivan) and I1c (Ingert) maps, with
> > their distribution in Croatia, North of the Black Sea, and North
> > Germany/Netherlands/England/Scandinavia and expected me to ask
> > annoying questions why this was so, so you initiated a counter
> > attack, before I could ask the question, which I am doing now:
> > What caused this odd distribution?
> >
>
> There are many possible explanations but I will present a scenario
> that in my opinion is the most likely.
>
> According to this scenario, the haplogroup I was introduced to
> Europe by the first wave of modern humans (Cro-Magnons) - circa
> 40,000 years ago. This is the only Y chromosome haplogroup that is
> almost completely absent outside Europe (if we don't count the
> relatively recent migrations of Europeans to America and Australia)
> and its sister haplogroup J is a major haplogroup in the Middle
> Eeast and Caucasus. There was a relatively early split within the
> haplogroup I, which corresponds to the two subclades Ia and Ib that
> are recorded today (for the most recent classification of the
> subclades see
> http://www.isogg.org/tree/ISOGG_HapgrpI08.html). All males from the
> Ia subclade (the <Scandinavian> one) share 15 newly acquired known
> polymorphisms (as opposed to only 6 known I-specific polymorphisms
> that are shared by all males from this haplogroup), suggesting that
> this subclade was separated from the remaining haplogroup I
> subclades a long time ago (and its homogeneity may indicate that
> all Ia males descend from a relatively small population that was
> able to survive and then expand in more recent times). By contrast,
> the Ib subclade splitted very soon (with both branches surviving
> till today) into I2a an I2b. Then the I2a subcalde splitted again -
> the I2a1 subclade is very frequent in Sardinia and occasionally
> seen in the Iberian peninsula, whereas the I2a2 subclade survived
> mostly in the Balkan peninsula, being very frequent in Bosnia and
> Croatia (but relatively frequent also in other Balkan countries,
> Moldavia, and even Ukraine). The second branch of I2 (the I2b
> subclade), represented mostly by I2b1 (formerly known as I1c),
> is most frequently seen in the Netherlands and Germany (about 10%
> of all Y chromosomes), but is also found in France and Slovenia.