GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2009-04 > 1238928192
From: "Tim Janzen" <>
Subject: Re: [DNA] Comparison of Chinese, Yoruba,Watson and Venter genome y-snps
Date: Sun, 5 Apr 2009 03:43:20 -0700
If you look at James' Genome SNPs Comparisons file you will note
that he lists 188 SNPs between Rows 304 and 491. These SNPs start with
haplogroup P and go down to 3 SNPs that James suggests are private SNPs in
the HUGO sequence. Of these 188 SNPs, all but 8 are found in both the
Chinese sequence as well as in the Yoruba sequence. The 8 SNPs that are in
question are found in the Chinese sequence, but not in the Yoruba sequence.
James categorizes the 180 SNPs that the Chinese and Yoruba male
share that appear to be between the PO node and the HUGO male as follows:
P or R?: 4
P+: 42 (derived under P)
R+: 15 (derived under R)
R1: 8 (P294, P242, P238, P225, P286, P236, P234, P233)
R1+: 10 (derived under R1)
R1b: 1 (M343)
R1b+: 12 (derived between R1b and R1b1)
R1b1+: 10 (derived between R1b1 and R1b1b)
R1b1b: 1 (P297)
R1b1b+: 34 (derived between R1b1b and R1b1b2)
R1b1b2: 3 (S10, S3, and M269)
R1b1b2a: 2 (L49 and S141)
R1b1b2a1: 1 (L51)
R1b1b2a1a: 3 (S127, S128, S129)
R1b1b2a1a2: 1 (S116/P312)
R1b1b2a1a2d3: 1 (S139/L2)
R1b1b2a1a2d3a: 1 (S144/L20)
Karafet, et al. (see http://genome.cshlp.org/content/18/5/830)
estimated the age of P as 34,000 years, R as 26,800 years, and R1 as 18,500
years. If we divide 34,000 by 180 then we get 188 years per SNP between the
HUGO male and the haplogroup P node, or approximately 6 generations per SNP.
One problem I see at this point is the fact that only 3 SNPs have
been identified at this point between the HUGO male and the L20 SNP. It
seems probable to me that there would be more than just three SNPs in this
interval. There is at least one SNP just downstream from L51, specifically
L52 (rs13304168) that I can't find in James' spreadsheet. I am not sure why
it wasn't included. Perhaps it is an unreliable SNP.
In any case, if you take the data as it stands and don't include L52,
then there are only 5 SNPs downstream from P312 and only 12 SNPs downstream
from M269. 12 times 188 is 2256 years as a rough estimate for M269 and 5
times 188 is 940 years as a rough estimate for P312. I think that this is
far too low for both M269 and P312. I have previously estimated P312 at
about 3500 years using the interclade variance method (see
55). I believe that Anatole Klyosov has estimated M269 to be about 4600
years old using a logarithmic method.
In addition to the 180 SNPs that James categorizes that the Chinese
and Yoruba male share that appear to be between the PO node and the HUGO
male, there are 246 other SNPs that the Chinese and Yoruba male share that
James hasn't yet categorized and haven't yet been placed on the Y SNP tree.
Ideally, these 246 SNPs should be placed on the next major SNP chip. Of
these 246 SNPs, 10 are shared by the Chinese and Yoruba male as well as by
Watson and Ventor. These 10 SNPs may well be eventually placed somewhere
below P312 on the Y SNP tree or they could prove to be errors in the HUGO
sequence. The rest of the 246 SNPs likely are found somewhere on the Y SNP
tree somewhere between the HUGO male and M168. Probably some of these 246
SNPs will prove to be errors in the HUGO sequence.
I think that we need more accurate complete R-M269 Y chromosome
sequences to help us sort some of these issues out. In particular, we are
going to need a highly accurate R-L20 Y chromosome sequence that we can
compare to the HUGO sequence to help us spot more errors in the HUGO
sequence. Ventor's sequence has proven to be useful, but contains a lot of
errors. Watson's sequence while very helpful is also not quite as accurate
as the Chinese and Yoruba sequences appear to be. It is possible that there
are some more downstream SNPs between P312 and the HUGO male in this file of
n/W_V-shared-SNPs.htm. However, my impression at this point in time is that
at least some of those SNPs are errors and aren't going to be between P312
and the HUGO male (particularly the SNPs between positions 57392694 and
57441017) since only 4 SNPs between positions 57392694 and 57441017 were
found to be shared SNPs by the Chinese male and Yoruba male.
[mailto:] On Behalf Of Alister John Marsh
Sent: Sunday, April 05, 2009 12:10 AM
Subject: Re: [DNA] Comparison of Chinese, Yoruba,Watson and Venter genome
Thanks for taking the time to give this breakdown. Very interesting.
Do you think we have got enough information yet from these SNP distributions
to hazard a refined assessment of the age of any R1b subclade nodes? At
least in a proportional sense since Y-DNA Adam.
Of the SNPs which you seem to think were reliably sequenced, approximately
one SNP per 4.5 generations seems some sort of measuring stick. How long
ago would that place the R haplogroup Ventor and Hugo tree node?
It is puzzling that Watson for different regions consistently has many less
SNPs than Ventor compared to Hugo, when Watson and Ventor are apparently the
same R1b subclade downstream of Hugo. Perhaps for most regions, it is safer
to compare Chinese and Yoruba to Ventor, rather than to Watson?
|Re: [DNA] Comparison of Chinese, Yoruba,Watson and Venter genome y-snps by "Tim Janzen" <>|