GENEALOGY-DNA-L ArchivesArchiver > GENEALOGY-DNA > 2009-07 > 1247895902
From: "Dennis Wright" <>
Subject: [DNA] Using Tim Janzen's TMRCA Calculator
Date: Sat, 18 Jul 2009 15:45:02 +1000
Tim Janzen has been discussing his Variance Calculator to estimate TMRCA for each Haplogroup and has offered it to others to try
out. I have taken him up on his kind offer.
Within the Irish Type III R-L21+ cluster, I have 110 haplotypes with full 67 markers ... and I will later have a look at using the
lesser 37 markers where I have 228 haplotypes.
I thought I might try using the Variance Calculator to find the TMRCA for each surname within the Irish Type III cluster.
The sample size for some surnames is limited and the confidence limits are obviously incorrect at the lesser end, but with these
provisos in mind I ran some numbers.
The figures below are using "Age in years for 67 markers using Ken Nordtvedt's method and Chandler's and Little's mutation rates
based on 30 years per generation".
All Irish Type III n=110 1041 ± 393 years
Bryan/Bryant/O'Brien n= 17 831 ± 396 years
McCraw/McGrath n= 7 606 ± 408 years
Hogan n= 3 405 ± 481 years
Hart n= 5 268 ± 298 years
Crow(e) n= 7 251 ± 263 years
Butler n= 7 178 ± 231 years
Casey n= 12 149 ± 190 years
Perhaps we can say that with a 95% confidence level,
The cluster is possibly as old as 1434 years
The Bryan/Bryant/O'Brien line could be up to 1227 years old
The McCraw/McGrath line could be up to 1014 years old
The Hogan line could be up to 886 years old
The Hart line could be up to 566 years old
The Crow(e) line could be up to 514 years old
The Butler line could be up to 409 years old
The Casey line could be up to 339 years old.
Certainly in the case of Butler, there is evidence that Murrough O'Brien married Eleanor Butler of of Bansha in 1690 taking her name
as part of his succession to the lands of Bansha, Co Tipperary. This is some 320 years ago and fits within the confidence limits of
Tim's Variance Calculator. It is believed that from this union the Irish Type III signature has appeared within the Butler name .
I will need to peruse the pedigrees to see if the other surnames can be matched in a similar way.
Has anyone else carried out similar calculations within their clusters?
Irish Type III
R1b1b2a1a2f* ... R-L21
mt DNA J1c1b
Ysearch/mitosearch ID 6PWCD
ISOGG Regional Coordinator - Australia
|[DNA] Using Tim Janzen's TMRCA Calculator by "Dennis Wright" <>|