GENEALOGY-DNA-L Archives

Archiver > GENEALOGY-DNA > 2003-11 > 1069595092


From: "Richard McGregor" <>
Subject: Re: [DNA] Genetic Distance calculation - Comments re MacGregor and a further question
Date: Sun, 23 Nov 2003 13:44:52 -0000
References: <1ec.13e271f9.2cf0ed2f@aol.com>


Some of us (more and more) are
> dealing with Irish or Scottish clan groupings with known or well-estimated
> pedigrees of 200 to 1600 years.

I thought the group might be interested in a few MacGregor statistics from
the MacGregor Project which have a bearing on the current debate. It seems
to me that in order to make meaningful relationships you need to know what
is the 'root' line. We have managed to identify this for those named
MacGregor. Of course not all those people who have the name MacGregor have
closely-related DNA but of those that do we see the following.

Particularly interesting in the light of the debate is the case of
individual 1 who is one mutation away from the 'root line' and individual 2
who is 2 away from the root line. There seems little doubt that both these
individuals have mutations away from the 'root' and, as it happens, the
mutation occurs at the same locus in both but in opposite directions. By
the stepwise calculation these two individuals who are related through the
root line would have a genetic distance of 3, and by the squaring method it
would be 5 ie (2*2) + 1*1).

[By the way I could envisage that with another individual this could easily
be 4 (2
mutations per individual) or by the square method it might be 8 ie (2*2)
+ (2*2). If there were a double mutation at a given locus in one individual
we would start to get into double figures with the squaring approach].

We believe from the traditional genealogies that the two individuals who
have a 3 mutation difference would have shared a common ancestor up to 700
years ago. Therefore in our current statistics 2 out of 14 show 3 step
mutations in up to 700 years

Of the 14 who share the 'root line' we have 9 individuals who share the same
DNA signature
(8 MacGregor and 1 Stirling - a known and documented MacGregor alias), 1
Stirling with one
mutation (385b), one MacGregor with one mutation at 464d, one with one
mutation at 449, one
with one mutation at 458, one with two mutations - one at 458 and one at
439.

In addition to these there is 1 individual whose distance from the 'root'
is 3 mutations on
separate loci and one whose distance is 4 at 4 separate loci. (I have not
counted these two
into the total of 14. We also hbve 1 Greig with 4 single mutations on 4
loci).

Of the others who have the surname MacGregor we have within the R1b group
5 individuals with between 6 mutations and 10 mutations away from the 'root'
counting
stepwise (only one of the 5 has a double mutation at one point).

Staying only with the name MacGregor we have one 'Viking' line (haplogroup
I)
(there is a second individual who did the only the Oxford Test would also be
'Viking');
one who haplogroup is J2 (this latter possiby a non-paternity event); and
one other who
may also be J but with enough difference to be a different branch. We can't
compare
these last two exactly because one has only done 12 markers.


My question is: if we know a rough date for the split of different
haplogroups, is it possible to identify a 'root' line for each haplogroup
and from this calculate mutations away from the 'root' rather than trying
to measure individuals against each other???

Richard McGregor
Clan Gregor DNA Project Co-ordinator



This thread: