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From:
Subject: Re: [R-M222] Ok what does all of this mean?
Date: Sat, 7 Aug 2010 18:11:08 EDT


Thank you John that was quite a lot of information. I appreciate you
taking your time to pass this on to us.

Billy Dunbar


In a message dated 8/7/2010 3:26:25 P.M. Central Daylight Time,
writes:

Perhaps we should explain a few terms we've been using on this list.

One that springs to mind is off modal matches.

To do that we should first define modal.

(statistics) A value occurring most frequently in a distribution

I'm sure you've seen references to the M222 or Nial modal. Another
common modal is the R1b or AMH (Atlantic modal haplotype).

Here's a definition of the AMH from Wikipedia:

"The AMH is the most frequently occurring haplotype amongst human males
in Atlantic Europe. It is characterized by the following marker alleles:

* DYS388 12
* DYS390 24
* DYS391 11
* DYS392 13
* DYS393 13
* DYS394 14 (also known as DYS19)"

Or the way we're used to looking at it:

13--24-14-11-

The "Nial" modal was originally developed by David Wilson (he called it
NW Irish) by comparing his own DNA (M222) to the AMH. Exactly why he
called it NW Irish has never been explained but he probably found
matches with his own DNA to the Dohertys of NW Ireland (Donegal), lthe
only large DNA project at the time that covered NW Ireland. The
McLaughlin of Donegal project hardly existed at the time. Only a few
Gallaghers had been tested. Many of the other surname matches could not
unambiguously be linked with NW Ireland.

In comparing this DNA to the AMH differences are obvious. Just to use
the markers above in M222 the modal value (most frequently occurring
value) at DYS 390 - 25, So:

`13-25-14-11

That can be done for every single marker in the 67 marker set. Where
M222 differs from the AMH we refer to the values as M222 modal markers.
There are five of them in the 1-25 marker set.

DYS 390 = 25
DYS 385ab = 11-13
DYS 392 = 14
DYS 437 = 18
DYS l448 = 30
DYS 464abcd = 15-16-16-17

There are other differences but those alone are generally enough to
identify M222.

The relevance of modal markers and in particular off modal marker values
is that DNA experts use them to discover new modals for broad
collections of haplotypes and for individual families as well. Some
modals are very strong (M222). Others less so. The strength of a modal
largely depends on the number of off modal marker values in the
collection of haplotypes. One or two matches may not mean anything.
Two of three is probably significant.

Mostly in this forum we've been taling about off modal matches to the
M222 modal. That's the method most DNA experts use to try and define
individual family clusters and look for possible sub-clades.

What you do is compare your collection of haplotypes (say a family
group) to the M222 modal. Note the differences at each marker. The
difference must be modal to mean anything (ie, the value must be the
most frequent value in the group of haplotypes compared). If you have
10 samples and 8 of 10 have 29 at DYS 389-2 then the modal value is 29.
The stronger the modal value the better.

I don't think there are yet any fixed rules on how to analyze off modal
markers. Some families have a lot. Some have few or almost none. The
McLaughlins of Donegal for example have three off modal marker values
within M222.

DYS 458 = 18
DYS 447 = 24
DYS 576 = 17

We have an entire cluster of McLaughlin samples that match this. Most
have all three off modal values. A few have two of three. Any less
than that and we exclude them from the group. This decision is
generally backed by genetic distance in that samples that match only one
of three off modal markers tend to be a huge genetic distance from the
others in the group.

Bear in mind that I am writing this not as a DNA expert but simply as
someone who has been exposed to these techniques by others. I've used
them ever since. I'll let others explain the technical aspects.

In our McLaughlin DNA project we have a large number of unrelated
McLaughlin clusters, some of which are different haplogroups (I, U106).
Others are M222 but do not match our Donegal cluster McLaughlins.
Others are part of the Leinster modal. Many others are close to the AMH
or R1b modal. If I take one Donegal McLaughlin DNA sample and compare
it to every other sample in the project, whether it matches or not, the
results almost invariably fall into distinct groupings based on genetic
distance.

I mention this only because there are occasionally arguments between the
"shared marker" and genetic distance camps, both of whom think their
methods are superior. I have no answer to this myself. Maybe both are
useful?

What most of us do is first attempt to work within our own surname
group. Note the off modal differences in your own DNA and then try and
find others of the same surname who match some or hopefully most of the
same off modal marker values. We are finding lots of unique family
modals in M222. People have also been finding at least a few modals
that extend beyond a single surname and take in a few others. So far we
haven't found any combination of markers that reliably divide M222 into
sub-ckades,

Genelaogy is extremely important in this kind of study. The only reason
we are able to identify our cluster of McLaughlins described above as
"Donegal McLaughlins" is because perhaps 20% of the group have either a
valid paper trail to Donegal or an oral family history of coming from
Donegal. I've seen large related groups where not a single sample can
be reliably located geographically. That makes it impossible to
determine anything. Even broad sweeping statements such as "I'm from
Ireland" or "Scotland" mean little, given the norm of multiple origin of
surnames. And those can be inaccurate or misleading as well. If your
ancestors came to Ireland from Scotland in the Plantation years or later
(1600 +) or moved to Scotland from Ireland in the 1800s you may not be
what you think you are. One of our co--admins in the McLaughlin project
always thought she was Scottish. Her father was so sure he legally
altered the spelling of his name to Maclachlan, a typically Scottish
spelling. Then she found a Scottish 1800 census record which said her
ancestor was born in Ireland. The family had no oral memory of such a
move.

A little trick you can use in searching for off modal matches to your
own DNA is structure what some call a skeleton haplotype or minimal
haplotype. Instead of using your Ysearch ID to look for matches, try
using the marker option. Use something like 13-25-14-11-13-13 plus
14-29, Add in every off modal marker found in your own DNA. Keep ;the
number of genetic mismatches to the absolute minimum or you'll get a lot
of hits that aren't really matches.

Most of the time you will just find members of your own surname
cluster. Sometimes you won't find anything but the samples in your own
project. But you might even find a new modal of some kind that links
different surname groups.

When we were working on the Leinster modal we started with Byrnes DNA.
There was a large group of related Byrnes in their project and other
samples in the Trinity database, all of which shared certain off modal
matches to the AMH. The Byrnes in this part of Ireland were a branch of
the Lagin in Leinster, traditionally related to the Kavanaghs and
Kinsellas, Murphys and a few other chieftains or kings in that province.
We then began. Kavanaghs and Kinsellas who matched the same off modal
DNA markers. Murphys too. Not all Kavanaghs matched, of course. But
the largest single related cluster of Kavanaghs did match the O'Byrne
modal. Most of the other Kavnaghs were stray bits of DNA that matched
at most one other sample. Another small cluster had only one ID point -
Co. Mayo. They most likely represent another sept whose Irish name was
corrupted into Kavanagh. Interestingly the Kinsellas we found and the
Kavanaghs lined up perfectly in the project, an exact match at off modal
marker values. They shared a common ancestor in Drmot MacMurrough, the
infamous Leinster King who invited the Normans into Ireland ca. 1200 AD.

That is basically the same approach Trinity took previously with their
NIal DNA study. They identified Irish surnames traditionally linked to
Nial in the Irish pedigrees and sent out DNA kits.



John



R1b1c7 Research and Links:

http://clanmaclochlainn.com/R1b1c7/
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