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DOR-Terrill YDNA Genealogy

by Conrad W. Terrill ( cwterrill@comcast.net ), 24 Feb 2021

Data Privacy: In compliance with the European Union data privacy laws in effect as of 25 May 2018, DOR-Terrill is no longer making public anyone's actual yDNA test results. What we are making public instead are the differences between those test results and a reference set—one which will remain private to those persons who have contributed their test results to this project. We call this reference set "Modal Roger1." It is an average, of a sort, of all the actual test results, as explained in the Modal Roger1 article below.

DOR's YDNA Roger section was first introduced in June of 2009. By April of 2010 we already had yDNA test result contributions from paternal line descendants of all five of Roger1's sons who had children (Joseph2 never married). Those test results alone gave us all the information necessary to determine Roger1's yDNA to 67 markers, with a very high level of confidence. You can read all about this, and a lot more, in our Modal Roger1 article. No known descendant so far has deviated from Modal Roger by more than four mutations, over approximately ten generations since Roger1. If you are male and believe you might be a male paternal line descendant of Roger1, or if you are female and have a male "Terrill" relative willing to be tested, you now have a way to prove that descent. We would certainly welcome you to join our the project. Read more …

Modal Roger1

by Conrad W. Terrill, 29 Mar. 2010

This occasionally updated article sums up our current YDNA results for descendants of Roger Terrill. "Modal Roger1" is our determination of Roger's YDNA, based on the modal (the most frequently occurring) value for each marker.

View the chart: (the complete set of results)

(Click here for an explanation of the chart)

Read all . . .

The DOR YDNA Roger STR tree

by Conrad W. Terrill, 21 Sep. 2011

Here are our YDNA Roger test results presented in tree form. The mutations define branch points which provide the means of identifying descendants along those branches. This is a work-in-progress which we intend to keep updated as new test results come in.

See the tree ...


The FamilyTreeDNA
Terrell Surname Project

by Conrad W. Terrill, 8 Feb. 2010

This occasionally updated article summarizes all the results posted to-date at the Family Tree DNA (FTDNA) Terrell Surname Project. The objective of the Terrell Surname Project is to sort out worldwide Terrells, to determine which are descended from which common ancestors, and to give those Terrells who do not well know their paternal line a means of tracing it back further, by connecting with those who do. DOR-Terrill utilizes the Terrell Surname Project to discover new descendants of Roger1, who are thereupon invited to join our Modal Roger1 group.

Read all . . .


Ufford Surname Project Launched

[posted 15 Aug. 2010]

New DOR member Jane Ufford Bartlett, a patrilineal descendant of Thomas Ufford through son John, has just launched an Ufford Surname Project, hosted by World Families Network

Read all . . .


FTDNA Marker Mutation Rates

by CWT, 4 Sep. 2010

New yDNA test results defy our earlier contention that marker CDYb is a mutation indicator for the Thomas2 line. We've also now seen two occurences of this same mutation in non-Thomas2 lines. This article addresses the issue, offering an explanation in terms of marker mutation rates.

Read all . . .


How to get tested

DOR-Terrill highly recommends that you get tested by Family Tree DNA, the company that we ourselves use. FTDNA is run by genealogists and scientists, gives exceptional service, and provides a complete product, including extensive help, many forums, and the surname projects which allow you to make genealogical use of your results.

Read all . . .


DOR-Terrill in the Deep Clades

by Conrad W. Terrill, 27 Apr. 2012

It is now possible, via yDNA deep clade testing, to learn your ancient paternal lineage, and DOR-Terrill has done this. This article presents and explains our test results. A second article, not yet finished, will attempt to interpret them, relying heavily upon the work of experts in this field. However, since there is no consenus of opinion among these experts, this planned extension could border on fiction.

Read all ...


Tom Roberts, descendant of Roger Terrill —a yDNA genealogy success story

by CWT and Thomas Roberts, Dec. 2010

It's not often that you are able to help someone blast through the kind of brick wall that Tom Roberts encountered in trying to trace his paternal line; but DOR-Terrill was able to help via our YDNA Roger project. Tom is as close a match to Modal Roger1 as all but one of our group. This was all it took to allow him to determine his paternal ancestry, albeit there is a gap of two to three generations. And Tom is now a bona fide descendant of Roger.

Read all ...


A yDNA Terry-Terrill Connection

by CWT, May 2011

Darryl Lee Terry, a descendant of a John W. Terry born about 1838 in South Carolina, has recently shown up as a very close yDNA match to Modal Roger1. This Terry-Terrill connection is intriguing. Is Darryl another descendant of Roger, one whose name has somehow mutated from Terrill to Terry? Is the connection much further back, in England, when surnames were much more fluid? Or is there some more mundane explanation, a "non-paternal event", possibly an adoption? DOR-Terrill has attacked the problem ...

Read part 1

Read part 2 (July 2011)


A yDNA connection to an early 1700's Tyrrell Surrey line

by CWT and NTT, 28 Aug. 2013

Dennis G. Tyrrell, of Australia, has been tested to 111 markers and matches us descendants of Roger1; but his ancestors left Surrey for Australia in 1849, and never lived anywhere but in Surrey prior to that. DOR has taken what Dennis knew of his paternal line and traced it back two generations further, to a Joseph Tyrrell who married in Surrey around 1749. This Surrey connection strengthens the credibility of a "monumental record" linking Roger1 to Surrey.

Read more …


On the paternal ancestry of Joseph Tyrrell of West Horsley in 1750

by CWT and NTT, 8 Oct. 2015

This article is a follow-up to the one above, attempting to extend the paternal line another couple generations back, to the mid-1600's.

Read more …