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Archiver > WEBB > 2003-09 > 1064127924
From:
Subject: Re: [WEBB] A LOOK at my WEBB DNA Study aggregate results so far
Date: Sun, 21 Sep 2003 03:05:24 EDT
In a message dated 9/20/2003 5:17:43 PM Central Daylight Time,
writes:
> Anne, you got layman's terms for all that?
>
> yvette
>
Trust you to ask me the tough questions <G>!
You might find the following reading useful:
DNA 101 http://blairgenealogy.com/dna/dna101.html
MARKERS & VALUES
We have 7 unique 12 marker strings, which I have assign
ed Group Names A - G simply for the convenience of discussion.
Group A has 3 participants, Group B has 2 participants, and all the other
groups have 1 participant each. This means the 3 folks in Group A had the EXACT
same values on all 12 markers, and Group B folks had EXACT matches on all 12
markers, but if you look at my chart, A does NOT match B.
Incidentally, I would expect Jesse WEBB to show up in Group A ::Smile::
Therefore, in simplest terms, we have so far 7 different WEBB lines.
That being said, we might need to talk about mutation rates. Y-Chromosomes
are passed down from father to son unchanged EXCEPT FOR RANDOM MUTATIONS. Now
these random mutations have a rate of about .002, which means one expects a
mutation about every 500 generations (or roughly 12,500 years). Let's look at
Groups F and D, which have an 11/12 match. The mismatch occurs in DYS#439
(the 9th one from the left) :
1 13 24 14 11 11 14 12 12 12 13 13 29 F Y-13
1 13 24 14 11 11 14 12 12 13 13 13 29 D Y- 6
These two groups may well have had a common ancestor 12,500 years ago. Of
course surnames were not used then, and that is far too long ago to be useful
for genealogy! If you notice, both these groups are strings which have shown up
under multiple surnames -- which suggests that as members of this DNA group
took on surnames over time, they didn't all take on the SAME surname. {WEBB if
you recall is an "occupational" surname, indicating ties to the weaving trade
at one time}. I have asked the fellow who did the surname study (John Blair)
what the surnames associated with the string are -- mostly out of curiosity.
I do not yet have a reply. It may be utterly meaningless, or it might turn
out they are all "occupational" surnames.
Some markers mutate more rapidly (although I don't have the rates for these).
In 12 marker strings, the "faster mutating" DYS#s are 385a, 385b & 439 (5th,
6th & 9th). OOPS! our F & D have their only mis-match at 439. What this
means is that their Most Recent Common Ancestor (MRCA) may have been more
recently than 12,500 years ago. If I knew what the "faster rate" of mutation for
that DYS# was, I could tell you now much more recently. However, I suspect this
merely reduces the time to MRCA from 12,500 to 10,000 or something, still not
enough to be truly useful to the genealogist. [NOTE to self, ask the
experts this one. DONE! Email sent off!] Therefore, for genealogical purposes, each
unique string of DNA markers is a SEPARATE WEBB Line, even if they had a
common ancestor 7500 years ago.
Since NONE of the WEBB 25 marker strings occurred in multiple surnames, they
can be considered "WEBB STRINGS." If for instance , someone turned up with
an EXACT match to one of these strings, but a different surname, it would be (I
think) reasonable to suspect some kind of formal or informal adoption
somewhere in the history of this person. This MIGHT be useful for genealogical
purposes, if there is conventional evidence to support it. For example, say
Susannah WEBB married Francis White c. 1750 and they had a son Daniel b. c. 1751.
Daniel's descendants turn up matching a WEBB line. This might suggest that
Susannah was married TO a WEBB before she married WHITE and was pregnant when
she married WHITE, but the child simply took on the WHITE surname, being born
after the marriage to WHITE. (We shall leave the darker alternatives unspoken,
although if one truly wanted to know, DNA might be able to answer that as
well. )
I included the analysis of unusual values on values of various markers
because my readings have suggested this MIGHT be helpful in determining more recent
relationships, and because I thought it was, in general, interesting. Quite
frankly, that was for the OTHER mailing list more than for the WEBB one. What
is interesting is that the one participant has so many unusual values on so
many markers.
HAPLOGROUPS
To put it most simply, a Haplogroup indicates the "deep" ancestral roots.
Anthropologists have taken the basic human tree and followed migrations of
populations and branchings. There are 18 major Haplogroups, or clades, named by
the letters A - R. Subgroups are named by placing a number after the letter,
such as R1. Some subgroups have subgroups, and this is indicated by the use of
a lower case letter after the number, i.e., R1b.
These tell you where your ancestors were living thousands of years ago
(although there is an exception to this which I will discuss later). The
preliminary test only SUGGESTS one's haplogroup. To confirm it, one has to order
another test called the Y-DNA SNP test, which is about the same price as the 12
marker test.
Most of our participants/strings had Haplogroup R1b. We did have three
participants who showed up as I. The occasional appearance of some other
haplogroups, as I understand it, suggests not that our participants have roots there,
but that the person in that haplogroup probably has some long forgotten ancestor
from the dominant haplogroup of our participant. For example, one of our
participants showed one Q haplotype match -- this is Native American. What is
likely here is that some I haplogroup male fathered a son with a Native American
long ago, but this has been forgotten or overlooked and the person now in the
Q haplogroup thinks he or she is wholly Native American. I found this
interesting because the Q match was to the I (Viking group). Descendant of Leif
Ericsson?
What I find interesting and potentially useful about this division of the
WEBB lines into R1b and I is that portions of the UK were heavily
Scandinavian....so I wonder if the I lines might have come from that part of the UK while the
R1b lines came from some other part? [I have asked the experts, but haven't
received the answer].
Haplogroup R1b is the most common haplogroup in European populations. It is
believed to have expanded throughout Europe as humans re-colonized after the
last glacial maximum 10-12 thousand years ago. This lineage is also the
haplogroup containing the Atlantic modal haplotype.
The I, I1, and I1a lineages are nearly completely restricted to northwestern
Europe. These would most likely have been common within Viking populations.
One lineage of this group extends down into central Europe.
The Q lineage is the lineage that links Asia and the Americas. This lineage
is found in North and Central Asian populations as well as native Americans.
This lineage is believed to have originated in Central Asia and migrated through
the Altai / Baikal region of northern Eurasia into the Americas.
Thank you for asking the question others were probably also wondering about!
Anne
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