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Archiver > DNA-R1B1C7 > 2010-09 > 1284153786

From: John Mclaughlin <>
Subject: [R-M222] TMRCA
Date: Fri, 10 Sep 2010 16:23:06 -0500
References: <AANLkTikdS_Y_Go4ZHDR4b5J44JKQ9JSceAbM1kC-PwvB@mail.gmail.com>
In-Reply-To: <AANLkTikdS_Y_Go4ZHDR4b5J44JKQ9JSceAbM1kC-PwvB@mail.gmail.com>

I used Tim Jantsen's ASD calculator to check on the McLaughlins in our
Donegal cluster (37 marker samples). The results returned from various
methods in the spreadsheet were:


1441 AD.
1295 AD.

This range appears to me to be on target. I'll say why in a moment but
first a note on the O'Clery Book of Genealogies and the MacLochlainn
data it contains.

Highly unusual in Irish pedigree collections, the O'Clery Book of
Genealogies contains a number of pedigrees which are not just main line
pedigrees common in other Irish MS. but full-fledged genealogies
purporting to show every member of the sept in descent from a common
ancestor. In general nen named in these genealogies can be dated to the
late 1500s or in some cases the early 1600s from names recognizable in
the text from historical sources. There are full genealogies for mostly
Donegal families (O'Donnells, O'Dohertys, O'Gallaghers) but very few for
others elsewhere in Ireland. That was probably due to the influence of
the O'Clerys, well known as historians to the O'Donnells and co-authors
of the Annals of Ulster in the 1600s.

In the case of the MacLochlainns of Donegal the O'Clery genealogies show
every MacLochlainn listed living in the late 1500s-early 1600s as
descendants of one man, a Neill MacLochlainn, living sometime around
1400 AD. According to the O'Clery MS. this man had three sons from
which descend three branches of the sept. The date can be calculated
roughly from the pedigrees. The Neill in question is five generations
in descent from Domhnall MacLochlainn, king of the Cenel Eoghain, slain
in 1241 AD. The date comes from the Irish annals, a battle fought
between the MacLochlainns and the combined forces of the O'Donnells and
O'Neills. If one assumes the standard 30 years per geneartion that
would place Neill sometime around 1400 AD. plus or minus. The date can
also be corroborated from the other end of the pedigrees going
backwards. They show a John McLaughlin, son of Dubhaltach, 5
generations in descent from said Neill. This man is documented in
English records and in 1622 received a lease of the lands of Clare in
Moville parish from Sir Chichester.

In another line we find a Brian oge McLaughlin, 6th in descent from the
same Neill, who is listed in English documents in 1601 as the current
chief of sept, holding a small castle on the Foyle shore named
Whitecastle. That too seems consistent with a common origin for the
various branches at about 1400 AD. His son, Donnell MacBrian oge also
received a 1622 lease in Moville parish under Sir Chichester.

The MacLochlainn surname first originated in the 11th century with
Ardgar MacLochlainn, the son of Lochlan, who d. 1054. His son was
Domhnall Ua Lochlainn, the Irish High King, who d. 1121. The annals and
tracts in genealogical MS. show several sons for Domhnall and others in
this line but if the O'Clery genealogies are correct then most lines
went extinct except for the line of Neill described above, common
ancestor of those McLaughlins named in the O'Clery MS. as living in 1600.

If one were interested one could do the same thing with the O
Dochartaigh genealogies in O'Clery. Probably the O'Donnell or
O'Gallagher genealogies as well. There are no such surviving family
trees for the O'Neills or O Cathains in the same MS, a strange ommision
but perhaps explainable by the O'Clery O'Donnell/Donegal bias.

If anyone would like a copy of the Jantsen ASD calculator you can find
it here:


My own tentative conclusion is that ASD TMRCA estimates do agree in
general with the known genealogy of the McLaughlins of Donegal, at least
for the sample set we have today (25).


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