GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2007-02 > 1171410179
From: Jim T <>
Subject: [DNA] There is no WAMH (R1b modal) cluster
Date: Tue, 13 Feb 2007 15:42:59 -0800 (PST)
There is no WAMH cluster, i.e., there is no R1b modal cluster.
Compare the results of these two Ysearch queries:
They both specify 67 markers with maximum genetic distance = 5.
The first specifies the R1b modals. The second specifies the
R1b1c7 modals. The R1b modal query finds just 1 man. The
R1b1c7 query finds 31 matches. If you increase maximum genetic
distance to 7, the R1b query finds 5 men, while the R1b1c7 query
finds 56. It seems that R1b1c7 is a real cluster and that the
This is probably obvious to those who have been looking for
clusters; they haven't found a cluster whose modals match the
R1b modals. It wasn't obvious to me a couple of years ago when
I first read about WAMH and clusters in R1b. I pictured the
structure of R1b as a tree with WAMH as the trunk, and the
various clusters as branches from the main trunk. I was puzzled
back then when I searched on the 37-marker R1b modals and found
no exact matches and few close matches. The picture has become
very clear now that there are over 800 67-marker R1b haplotypes
in Ysearch. R1b consists of many clusters, large and small,
that are not particularly close to the WAMH or, in most cases,
to each other.
Why does this matter? One reason is that the cluster structure
of a haplogroup can affect the calculation of marker mutation
rates. GATA-H4 is one example of this. Several of the largest
67-marker R1b clusters in Ysearch have non-modal values for H4.
The variability of H4 within each cluster is extremely low. If
you look at R1b as a whole, the variability of H4 is
significantly higher because of the non-modal values of a few
large clusters. This means that if you calculate a mutation
rate for H4 on the basis of its variability in R1b as a whole,
you will get a mutation rate that is too high.
As someone whose 67-marker haplotype was relatively close to the
R1b modal haplotype, I felt that my haplotype wasnât as useful
for genealogy as haplotypes that were further from the modal,
and I ordered many of the DNA-Fingerprint markers. Iâm glad I
got the additional markers because I got some interesting
results, but I really didnât need to get them. Although Iâm
fairly close to the WAMH, Iâm not close to any cluster of
67-marker results (at least not yet â more clusters will
become apparent as more 67-marker results are uploaded to
Ysearch). On the other hand, someone whose haplotype is near
the modal of one of the large clusters will have many more
spurious matches than I will. They are more likely to need to
test additional markers to differentiate lines.
I used to think that the WAMH was essentially identical to the
haplotype of the MRCA of R1b1c. Iâm not so sure about that
anymore, given the structure of R1b. I still think that it is
probably true that the modal of the slower markers is their
ancestral value. I doubt whether we can reliably deduce the
ancestral values of the faster markers with the data that we
have at the moment.
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|[DNA] There is no WAMH (R1b modal) cluster by Jim T <>|