Archiver > Y-DNA-HAPLOGROUP-I > 2008-02 > 1202243905

From: "Ken Nordtvedt" <>
Subject: Re: [yDNAhgI] The Story of I1b1 (P37.2+)
Date: Tue, 5 Feb 2008 13:38:25 -0700
References: <000a01c86822$34b4cca0$6400a8c0@Ken1><000301c86835$9ee51db0$6401a8c0@D1SC0XD1>

Each of the 6 generation numbers is distance BETWEEN two founders. So the
1152 generations is the total tree branch length BETWEEN the I1b1-Dinaric
founder (MRCA) and the I1b1-Western founder (MRCA). And similarly for the
other 5 generational distances.

As I said in the "story", I took an average of the I1b1-Isles clades as
representing them all. The internal generational distances between the
different clades of Isles are small. See the warpedfounderstree for


----- Original Message -----
From: "Ralph J. Games" <>
To: <>
Sent: Tuesday, February 05, 2008 1:28 PM
Subject: Re: [yDNAhgI] The Story of I1b1 (P37.2+)

> Ken clarification please I appreciate the information please correct my
> insertions below if they are incorrect.
> Ralph
> Western <-> Dinaric = 1152 generations, [I1b1-Dinaric?]
> Western <-> Isles = 880 generations, [I1b1-Western?]
> Western <-> Sardinian = 816 generations, [I1b1-Isles-A?]
> Dinaric <-> Isles = 528 generations, [I1b1a-Sardina?]
> Dinaric <-> Sardinian = 848 generations, [I1b1a-Isles-C?]
> Isles <-> Sardinian = 784 generations, [I1b1-Isles-B?]
> -----Original Message-----
> From:
> [mailto:] On Behalf Of Ken
> Nordtvedt
> Sent: Tuesday, February 05, 2008 10:09 AM
> To: ;
> Subject: [yDNAhgI] The Story of I1b1 (P37.2+)
> Over 20,000 Years of I1b1 (P37.2+) Haplogroup
> Although I'm personally double I1a, the history of y-haplogroup I1b1 is
> more
> interesting, so I'll first give the P37.2+ story as best can be told with
> present data. The warpedfounderstree file and spreadsheet of founder
> haplotypes file at http://knordtvedt.home.bresnan.net will be helpful in
> following this story. I1b1 (as called by the ISOGG) is a major haplogroup
> of y-haplogroup "I" and defined by the SNP P37.2+. It's still called I1b
> by
> FTDNA, but that will soon change. It has four major clades --- Dinaric,
> Western, Isles, Sardinian --- representing four greatly separated clusters
> of extended haplotypes, each found with a clear difference of geographical
> distribution in Europe. The clades have no present defining SNPs except
> for
> Sardinian, and this story really depends in no significant way on presence
> or absence of useful SNPs. But I have no doubt at all that each clade
> could
> have its own defining SNP, or multiples of them, if focused searches were
> made for them. !
> Although the Isles clade of I1b1 by itself is already divided into four
> sub-clades, I combine them as a single clade for purposes of this story;
> and the distances (generational times) between the clades within
> I1b1-Isles
> are short compared to the other inter-clade generational distances as you
> will see if you view the warpedfounderstree at my website.
> Using 52 of the slowest mutating markers available in our public
> databases,
> I established the modal haplotypes for each of the four clades of I1b1.
> These are our best determinations for the original haplotypes of the
> respective founders (MRCAs) for the presently assembled clade populations.
> The sum of real, measured mutation rates for my 52 markers used in these
> haplotypes is about 1/16. That means that on average each unit of
> genetic
> distance (GD) between haplotypes represents 16 generations of branch
> length
> between the founders represented by the pair of compared founding
> haplotypes. From my matrix of GDs, adjusted for back mutations, between
> all clade founders in y haplogroup I, we therefore have estimates for all
> the branch lengths between the four clade founders. These six lengths
> are::
> Western <-> Dinaric = 1152 generations
> Western <-> Isles = 880 generations
> Western <-> Sardinian = 816 generations
> Dinaric <-> Isles = 528 generations
> Dinaric <-> Sardinian = 848 generations
> Isles <-> Sardinian = 784 generations
> These four individual males each lived a specific number of generations
> ago.
> The task is to construct a tree of descent which begins with a P37.2+
> common ancestor to all I1b1 clades and whose total tree branch distances
> between each pair of clade MRCAs are as true as possible to the six
> generational distances given above which come from our observations. Such
> a
> tree pins down the relative times of existence for those four founders.
> This has been done and is shown as the red portion of the entire y
> haplogroup I tree given in file warpedfounderstree (in two formats) at my
> website. The arrowheads represent the MRCAs (founders) for the respective
> clade populations seen today.
> Note that the MRCA of all four I1b1 clades existed over 17,000 years
> earlier
> than the I1b1-Dinaric clade MRCA. This latter founder existed perhaps
> only
> 4000 years ago. So the overall P37.2+ MRCA existed prior to the European
> climate's fall into its last glacial maximum (LGM). And the branch line
> which eventually leads to the Sardinian clade MRCA leaves the rest of the
> P37.2+ tree quite close in time to the initial breakup of I1b1 as well.
> The
> branch line which leads to the I1b1-Isles founder leaves the branch line
> leading to I1b1-Dinaric founder at an appreciably later time, however.
> This
> is an inferred consequence of the smaller GD between the Dinaric and Isles
> founders that we observe.
> Brief Resume of Each Clade of I1b1 (P37.2+)
> Dinaric. This is the original clade of P37.2+ discussed in the
> literature.
> It is mainly found in Eastern Europe with frequency peak in Bosnia and
> Croatia, near the Dinaric Alps. Its frequency falls rapidly as one moves
> into northeast Italy or into Germanic lands. The I1b1-Dinaric haplotype
> population looks remarkably young; the full implications of this youth for
> the ancient migratory history of Eastern Europe are yet to be fully
> understood in my view. Dinaric I1b1 is the most populous clade of P37.2+
> in
> Europe.
> Western I1b1 is located more to the northwest in Germany, but appreciable
> amounts of it are found in the British Isles as well.
> Isles I1b1 is almost exclusively found in the British Isles and especially
> Ireland. Its haplotype population shows much diversity which with its
> absence on the mainland suggests the clade arrived or was founded in the
> Isles very early in the post-glacial repopulation of that region.
> Sardinian I1b1a accounts for about a third of Sardinian ydna, but it is
> also
> found at decent frequencies in regions of Italy and Iberia. It is also
> scattered up the Atlantic seaboard of Europe and into the British Isles.
> This pattern suggests it moved north in the same demographic movements
> that
> brought Atlantic R1b1c to northwest Europe. SNP M26+ defines this
> subhaplogroup of I1b1, but its extremely unique YCAIIa,b motif makes an
> unnecessary for its identification.
> It is interesting that only the tiniest trace of all four of these clades
> of
> I1b1 are found in Scandinavia. This seems a useful clue to me in
> eventually
> sorting out the movements of y-haplogroup I during its participation in
> repopulating Europe post-LGM.
> What happened over the 550 generation branch line that goes from the MRCA
> for all of I1b1 to the I1b1-Western founder (MRCA)? Certainly 550
> generations of father to son transitions did not go by with just a single
> son being born each generation. But over that long span of generations,
> all
> second and third son descendant lines went extinct. This can not be known
> to be exactly true, but is rather what is seen to fractional accuracy of a
> part in several thousand --- the number of y haplogroup I haplotypes which
> have been examined by population studies up until now. All P37.2+
> haplotypes found so far fall into one of the four clusters here discussed.
> That is not to say that some outlier haplotypes won't be found in the
> future
> in larger databases showing additional small clades of P37.2+, but any
> such
> additional clades will be demographically marginal.
> But over these 550 generations the line's haplotype handed down father to
> son each generation slowly changed by the random mutations which occurred
> on
> its 52 STR markers. So the end result --- the founding (modal) haplotype
> of
> the I1b1-Western MRCA --- is quite different from the original P37.2+
> haplotype of 20,000 years ago. Additionally, that haplotype moving
> through
> those 550 generations accumulates unique SNP mutations which today would
> be
> found in I1b1-Western haplotypes but not in any of other I1b1 clade
> haplotypes. If we assume the suggested rate of y chromosome SNP mutations
> of about one for each father-son transition, there should be about 500
> SNPs
> which each could define the I1b1-Western clade. A dedicated search for an
> I1b1-Western clade SNP which covered at least 1/5 of one percent of the y
> chromosome should stand a good chance of finding one of these SNPs.
> Where
> along this branch line of 550 generations would that SNP have occurred?
> We
> will never be!
> able to say; it has about an equal chance to be anywhere along that
> branch. We can infer the times when contemporary population MRCAs lived
> in
> the past; we can infer the times when branch points in the phylogenetic
> tree
> took place, but SNPs can only be placed as having taken place somewhere
> on
> a branch line. It is unfortunate that so much academic literature puts
> estimated dates on occurrences of SNP mutations, because that then
> requires
> some translating or restating to arrive at what we know from the data.
> Fundamentally, we date clade populations MRCAs.
> You will notice a dashed line in the warpedfounderstree file called
> "present" lying somewhat to the right from the clade MRCA arrowheads.
> Location of the "present" relative to the tree of MRCAs was done by
> determining the variances of several of the y haplogroup I clade haplotype
> populations. These variances can be converted into estimates of the times
> between the clade founders and the present. I generally find such times
> to
> be younger than much of the literature does because I use the actual
> measured marker mutation rates rather than fictitious "effective" rates as
> seen in many papers.
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