Making the most of your Britton DNA

Whether your oldest BRITTON ancestor is a male or female, DNA testing can help to identify your ancestral Britton line.  However, you may need to apply different DNA analysis techniques before you can confirm your Britton pedigree and to be confident of valid connections back to their original homeland.

There are three DNA tests that might help depending on where your Britton sits in your pedigree:

* Autosomal-DNA test at AncestryDNA, Family Tree DNA, My Heritage or 23andMe - for both males and females whose ancestry is expected to be Britton on any of their ancestral lines;

* Y-DNA test at Family Tree DNA - for male Britton's whose ancestry is expected to be Britton on their paternal line, ie. father, fathers father, fathers paternal grandfather, etc;

* mt-DNA test at Family Tree DNA - for both males and females whose ancestry is expected to be Britton on their oldest maternal line ancestor, ie.mother, mothers mother, mothers maternal grandmother, etc.

Is your line DNA confirmed?

Y-DNA tests can be expensive, particularly the best test - the Big-Y.  So before you make an investment in these types of Y-DNA tests, make sure your Britton line appears to be DNA confirmed through autosomal testing first.  Approximately 25% of DNA testers find there is a break in their line due to unexpected parentage events, adoptions etc.  

The recommended strategy is:

* Test at AncestryDNA first and ensure you have DNA confirming your Britton line up to your 2nd great grandparents.  AncestryDNA is particularly recommended for Americans and Australians due to the large numbers of testers from these countries.  AncestryDNA has the largest database of DNA testers plus many family trees which helps to identify connections.  Try to test all your older relatives who would have Britton DNA, male and female;

* Testers at AncestryDNA should upload their results to a chromosome analysis site to achieve the best results, particularly if you wish to confirm your pedigree beyond 2nd great grandparents.  Refer to Leah Larkins DNA Geek blog for instructions;

* If you test at AncestryDNA or 23andMe you can upload your results for free to FTDNA, My Heritage and GEDMatch which will assist in making more connections.  Testing at FTDNA and My Heritage can also enable you to upload to these sites but unfortunately you cannot 'transfer in' to either AncestryDNA or 23andMe;

* Once your Britton line is confirmed through autosomal testing, test the oldest male BRITTON ancestor at FTDNA for their Y-DNA.  STR testing should be at least at the 37 marker level and up to 111 markers (if you can afford it).  The Big Y is even more expensive but will provide details of SNP's which will better position your ancestor in the Haplogroup tree.  Y-DNA testing can confirm ancestry back many thousands of years, much more than autosomal tests and is best for connecting more distant ancestors.

BRITTON Autosomal (au/at) DNA Testers

Testing your au/at-DNA can be undertaken at a variety of companies including AncestryDNA, My Heritage, FTDNA and 23andMe.  If you have tested your au/at-DNA which includes a Britton ancestor you should also:

* Upload your results to FTDNA.  If any your ancestors have connections to Ireland please also join our Brittons of Ireland project (all counties welcomed);;

* Use the FTDNA advanced matching tool to find other matches in the Britton project;

* Upload your results to GEDmatch to connect with testers from other DNA testing companies;

* Join the GEDmatch Ancestors Project to find other matches in the Britton project. Under free tools on the GEDmatch homepage, search for Britton;

* Use the same file to also upload to My Heritage which is also free - you may as well 'swim in all the ponds';

* Unfortunately you cannot upload results to AncestryDNA and 23andMe, you will need to test there;

* Instructions for downloading from AncestryDNA and uploading to other sites can be found here.

BRITTON Y-DNA Testers

Y-DNA tests can only be undertaken at FTDNA.  You should test at least 37 markers (up to 111), or do the Big-Y - for best results the most you can afford is recommended.  You should also join projects and add your results to third party tools to maximise your connections and hopefully identify your oldest Britton patriarch:

* Join the Britton FTDNA Surname project ;

* Use the FTDNA advanced matching tool to find other matches in the Britton projects;

* Add your results to mitoYDNA project.

BRITTON mt-DNA Testers

mt-DNA tests can only be undertaken at FTDNA.  If you have tested your mt-DNA which includes a Britton ancestor on your maternal line you should also join projects relevant to your mt-DNA haplogroup and add your results to third party tools to maximise your connections and hopefully identify your oldest Britton matriarch:

* Join a haplogroup project at FTDNA;

* Add your results to mito mtDNA project.

Communicate with other BRITTON cousins

* Join the Britton's of Fermanagh Facebook Group.

Increase your chances of connecting with other BRITTON 's

* Add your pedigree to a 'One World Tree' - we recommend WikiTree;

* Add your Britton's to our 'One Name Study' at Wikitree;

* Add your oldest Britton patriarch to our 'Patriarchs' list at Wikitree;

* Add your oldest Britton matriarch to our 'Matriarchs' list at Wikitree.

Other information

Read more about my family on 'The Genemonkey' blog, it includes 2 posts which talk about our Britton DNA project - Cassidy and Brittons of Fermanagh, Ireland.

As part of the recent 2022 Cassidy Clan Gathering in Fermanagh Ireland, I prepared two presentations that are now on You Tube.  I hope you might find of interest, they are both approximately 30 mins each.  The first focuses on the nuts and bolts of DNA testing, what, who and why you should test.  The second focuses on my Cassidy and Britton family and what I have been able to achieve through DNA testing.

* Making the most of your Cassidy DNA (can be applied to Britton DNA);

* Finding my Fermanagh family with DNA.

More help

If you need help with Wikitree or other aspects in this post, please do not hesitate to contact me via the contact form on this blog, by private message at Wikitree.

Types of DNA evidence and how much you need

This blogpost is an attempt to summarise the typical types of DNA evidence that might be used to support genealogical conclusions when using genetic evidence.  It is intended to be used in conjunction with the DNA Case Study Template developed by Danielle Lautrec. These documents are to be discussed at the SAG: DNA Tools in Practice Meeting on 16th December 2023. It should be noted that these are my views and others may disagree.  As always, I welcome your feedback.

How much evidence is needed?

In 2021 I first wrote about the DNA Research Methodology.  This research methodology promotes slight variations depending on whether you are looking at close relations, such as 3rd cousins or closer, or more distant ancestors.  We need to adopt a similar approach when confirming genetic relationships, with additional evidence needed and more rigour applied when looking at distant relationships beyond 2nd great grandparents, or where there is no paper trail.

Not all DNA conclusions need the same level of supporting evidence, we need to think of it as a continuum.  Often it will be the impact the decision will have on others that will drive how much evidence is needed, particularly if the person or their close family are still alive.  There will also be differences if your ancestor left behind a strongly documented paper trail, or if you have started with a blank sheet!  

When assessing close relationships, genetic conclusions need to be ‘beyond reasonable doubt’  particularly where there is no existing paper trail and they affect living people.  

In contrast, given the passage of time, conclusions regarding more distant relationships may not always need to be ’beyond reasonable doubt’.  However, as DNA inheritance is random these decisions still need to be supported by sufficient genetic evidence to support the hypothesis on ‘the balance of probabilities’ consistent with Genealogical Standards.  

Naturally, genetic evidence cannot be used in isolation. Any conclusion reached needs to be reasonable and defensible, supported by other contextual information and genealogical records.  Continue to gather more evidence to move up the continuum.  

Examples of DNA evidence

The following table summarises the types of evidence you might use when documenting your conclusions and are expanded upon later in this post.  There are probably more types of evidence that could be used but I suspect these are the main ones.  

Evidence examples	3rd cousin and closer	More distant relationships
1. Individual DNA matches - Assess likely shared cMs range for relationship	Can be confirmed with documented paper trail, if relationship and range met Segments for close cousins can be utilised to build pedigree segment base for ancestors (only indicative without triangulation).	Indicative only - need additional confirmation including shared match groups and triangulation. Segments for close cousins should be utilised to ‘walk back’ the segments to more distant ancestors.
2. Triangulated DNA matches/groups - Assess likely shared cMs range for relationship	Can be confirmed with documented paper trail, if relationship and range met. Segments for close cousins can be utilised to build pedigree segment base for ancestors (triangulation ensures segments confirmed). Helps to build hypothesis for no paper trail.	Those with ‘tree and segment triangulation’ can be confirmed with documented paper trail, provided triangulation fundamentals are met. Segments need to be verified by ‘walking back’ the segment, confirming earlier generations first. Utilise visual phasing data when available. Triangulated groups help to build hypotheses for no paper trail.
3. Shared match groups and cluster reports	Tree triangulation within shared match clusters such as DNAGedcom.   Tools such AncestryDNA Thru-Lines and Theories of Relativity at My Heritage strengthens the evidence. Helps to build the hypothesis for close cousin relationships.	Indicative only - shared matches <30cMs need to be examined very carefully when determining shared match groups. Can be used to support hypothesis where there are members of clusters also in ‘triangulated segment groups’ with ‘tree triangulation’.
4. WATO charts	Relationship probability tool best used for predicting close relationships. For predicted probabilities to be more reliable, matches need to be 40cMs or greater.	WATO charts can be useful as a visual aid but as distant matches are usually <40cMs probabilities cannot be relied upon. Helpful for documenting matches and overlaying other evidence that support the hypothesis, ie. where triangulated groups or clusters exist.
5. Ethnicity reports	Percentages more useful where unique ethnicities exist. 25% = likely grandparent, 12.5% = likely great grandparent etc.	Indicative only - Smaller percentages can be a mix of both sides and need to be used with caution.
6. Y-DNA and mtDNA	Best for confirming more distant relationships on patrilineal and matrilineal lines - ideal for testing hypotheses.

1. Individual DNA matches - shared cMs

All DNA sites have relationship predictors, for this post I am using the one from AncestryDNA.  Another popular predictor is the Shared cM Project Tool at DNA Painter.

For each of the following three matches, I have identified our most recent common shared ancestors, but can I confirm the genetic relationship with just match details alone?

View larger image

Match A - Joanne:

* The paper trail for Joanne and me is strongly documented, our relationship being 2nd cousins, sharing great grandparents (Coat-Bradley);

* The shared cMs of 227 over 10 segments in 69% of cases is suggestive of a 2nd cousin relationship;

* Given the paper trail and the genetic evidence points to a 2nd cousin relationship (3rd cousins or closer), we can confirm the DNA match;

* The 10 segments shared with Joanne will be very helpful to further analyse more distant relationships and it is recommend that close matches be requested to upload to a chromosome site if possible;

* Until each segment is analysed individually there is no guarantee that all 10 segments came from the same common ancestor.  In fact, as Joanne shares great grandparents with me, each of these segments will probably have been inherited from different 4th or 5th great grandparents from either one of the 'identified MRCA couple';

* Segments from close cousins are the starting point for 'walking back the segments' and confirming your more distant ancestors.

Match B - Jennifer:

* There is 'no paper trail' for Jennifer and me, as our relationship is on my unknown great grandfathers line;

* The shared cMs of 54 over 3 segments in 37% of cases is suggestive of a relationship as close as a 3rd cousin;

* I have undertaken detailed genetic analysis not documented in this post and I believe my great grandfather to be one of three brothers of Prussian descent.  Based on Jennifers shared matches, her connection is also probably on this line;

* If my hypothesis is correct, my genealogical research suggests Jennifer is most likely a 'double' cousin, sharing two sets of common ancestors (one at the 4th cousin level and the other at 5th cousin level);

* If I had only identified one of the cousin relationships, I would have found that a fourth cousin relationship was likely in only 4% of cases - a trigger that further research was needed;

* Given there is no paper trail and the genetic evidence is beyond 3rd cousins or closer (ie. more likely a distant relationship), we cannot confirm the DNA match without further evidence;

* Ideally, the 3 segments shared with Jennifer need analysis at a chromosome site if possible;

* Until each segment is analysed individually there is no guarantee that all 3 segments came from the same common 'ancestor couple' or whether they split between the 'two ancestor couples';

* Shared match groups and clusters for this match need to be carefully examined, to ensure they are not inadvertently allocated to the wrong ancestral couple group;

* This match can only be marked as 'tentatively confirmed' to both ancestor couples.

Match C - Peter:

* The paper trail for Peter and me is strongly documented, our relationship being 4th cousins once removed, sharing my 4th GGP's (Richards-Coggan);

* The shared cMs of 21 over 2 segments for a 4th cousin once removed relationship is only found in 11% of cases, which is at the lower end.  In contrast, many closer alternate relationships are suggested.  Is the genealogy wrong?

* Whilst we have a paper trail the genetic evidence is low.  As the relationship is also distant (greater than 3rd cousins) we cannot confirm the DNA match without further evidence;

* The 2 segments shared with Peter need analysis at chromosome site if possible;

* Until each segment is analysed individually there is no guarantee that both segments came from the same identified 'ancestor couple';

* Based on the analysis being solely at AncestryDNA this match can only be marked as 'tentatively confirmed'.

2. Triangulated DNA matches

Chromosome analysis sites have an advantage in providing segment details for our matches.  'Segment Triangulation' is a process applied to identify matches who have tested their autosomal DNA and all match on the same chromosome, in the same segment area and all match each other.  It is applied to all chromosomes 1-23 and is evidence of a shared common ancestor.  

These groups of matches are called 'triangulated groups'.  We can confirm the match if we can also identify 'Tree Triangulation' for at least 3 matches in the triangulated group, provided triangulation fundamentals are met (for more information on triangulation concepts refer to the resource list at the end of this post).  

The 23rd chromosome has unique inheritance properties which can be useful for narrowing down relationships. Whilst all companies test the 23rd chromosome (also called 'X'), you can only view these matches at GEDmatch, 23andMe and FTDNA.

Match B - Jennifer:

* Jennifer has not transferred her results to a chromosome site;

* However, her son has tested at My Heritage and shares 36cMs on one segment on Chromosome 13;

* A triangulated group has been established, consisting of several matches who have ancestors from Germany;

* Whilst the genetic evidence confirms the group shares a common ancestor, without 'tree triangulation' we are unable to determine which of the two possible shared ancestor couples is the relevant one;

* As the segment inherited by the son is the same size as the largest of Jennifers 3 segments, we can conclude that the other 2 segments may be quite small and potentially the shared ancestor for those segments may be a long way back (possibly back further from one of the 4 likely 3/4th GGP's);

* Our confidence level that this is a confirmed DNA match may have increased given the genealogy of the triangulated group on chromosome 13, but without 'tree triangulation' with a third match it can still only be marked as 'tentatively confirmed';

* Without further evidence we still cannot assign the match/segment to either one of the two sets of possible shared ancestors 3GGP's (Noll-Zimmerman) or 4GGP's (Wedding-Rawolle).  For the purposes of my ongoing analysis the match/segments can only be assigned to the lowest level of confidence, in this case my 2nd GGP's (Noll-Wohling).

NOTE:  Current issues at MH prevent adding a triangulation image to this post.  

It will be updated when available.

Match C - Peter:

* Peter uploaded his results to GEDmatch which enabled analysis of our match at the chromosome level;

* GEDmatch indicates we share 13.4cMs on Chromosome 13 and 15.6cMs on Chromosome 14, a total of 29cMs.  Whilst AncestryDNA estimated we shared 21cMs over 2 segments, it is not unusual for variations like this to occur due to difference in reporting rules;

* By examining other matches who matched on the same chromosome, I identified another match descended from the same couple I shared with Peter, my 4th GGP's (Richards-Coggan).  This match also matched in the identical segment area on both chromosomes;

* My analysis has identified 'Segment Triangulation' AND 'Tree Triangulation' on both segments providing evidence of shared common ancestors, my 4th GGP's (Richards-Coggan), for Peter (4th cousin once removed) and a 5th cousin once removed;

* Given the paper trail is robust for both matches and the genetic evidence is confirmed by 'Segment Triangulation' (distant relationships), we can confirm both DNA matches.

3. Shared Match Groups and Cluster Reports

Shared match groups at AncestryDNA are very useful for classifying your matches into grandparents groups and more distant ancestral groups.  They are most useful for classifying matches to the grandparent and great grandparent levels.  Difficulty arises for more distant cluster groups as we are unable to view how matches match each other, unless we have access to individual match lists. 

Another useful tool is DNAGedcom which can provide a visual representation of cluster matches and also displays which matches are in common with each other.  The images used in this section were extracted from DNAGedcom with matches down to 20cMs consistent with AncestryDNA shared matches.  

Remember however that DNAGedcom provides us with details of 'shared matches' not 'shared segments' so these reports are always 'clues'.  We can hypothesise about what they are telling us based on the number of shared segments for each match and using other known 'triangulated segment' data.

Match A - Joanne:

* In this case we know the relationship, have a strong paper trail and have DNA confirmed the 2nd cousin match (3rd cousin or closer); 

* Unfortunately Joanne does not have her results on a chromosome site, however her brother is on FTDNA but not AncestryDNA;

* Shared matches with Joanne at AncestryDNA show 38 shared matches, that could come from any of the 4 ancestral lines associated with our shared great grandparents;

* Of these matches I have identified shared ancestors for 27 of them, split between all 4 possible ancestral lines.  10 remain unidentified;

* The DNAGedcom report suggests 3 key main cluster groups and based on the matches included are consistent with our 4 shared 2nd GGP's.  The cluster report is supported with many interrelationships common for a close relationship like 2nd cousin.  Only 24 matches appear in the DNAGedcom report suggesting that the other 13 matches may not also share other matches over 20cMs with Joanne;

* 13 shared matches have their results on a chromosome site, all of whom are triangulated with Joanne's brother, on multiple chromosomes at GEDmatch, providing further evidence that our DNA confirmation was correct;

* The triangulated data for Joanne's brother adds further weight to the evidence that the shared matches appearing in these groups and clusters are also likely to be related on the same ancestral line.

Match B - Jennifer:

* The hypothesis for this match is that Jennifer is a 'double' cousin, both a 4th and 5th cousin, related to me via two sets of shared ancestors Noll-Zimmerman (3GGP's via Noll-Wohling 2GGP's) and Wedding-Rawolle (4GGP's via Noll-Wohling 2GGP's and Wohling-Wedding 3GGP's);

* There is a high level of confidence regarding the largest segment match due to identifying a triangulated group on Chromosome 13 with Jennifers son, but without 'Tree Triangulation' the shared ancestral couple has not been identified;

* There are 18 shared matches with Jennifer at AncestryDNA, all of whom are consistent with being connected on my Prussian line, ancestors from my 'mystery' great grandfather, his parents Noll/Wohling (2GGP's).  13 matches have identified MRCA's, 2 x Noll-Wohling; 3 x Wohling-Wedding; 6 x Noll-Zimmermann; and 2 x Wedding-Rawolle; 

* The DNAGedcom shared match cluster report shows Jennifer in Cluster 22 with nine others.  7 of these share the ancestors of Noll-Zimmerman (3rd GGP's). A number of matches in Cluster 22 also share with others from Clusters 9 and 11;

* Jennifer shares with two matches from Cluster 9 sharing the MRCA of Wohling-Wedding (2GGP's); 

* Jennifer shares a match from Cluster 11 sharing the MRCA of Wohling-Wedding (3GGP's);

* Jennifer shares a match from Cluster 14 sharing the MRCA of Wedding-Rawolle (4GGP's);

* The many shared matches within the various cluster groups appear to support the hypothesis;

* Cluster 22 provides further evidence to support the relationship of Jennifer to the shared ancestral couple of Noll-Zimmerman;

* It can be concluded that the shared matches with Jennifer in Clusters 9, 11 and 14 are all potentially segments from the Wedding line.  This further supports the shared ancestral couple of Wedding-Rawolle and could be an indication of shared segments 'walking back up the line';

* It still remains unclear from looking at clusters alone which ancestor group is the MRCA for the triangulated group with Jennifers son on Chromosome 13.  Looking at the sheer numbers of confirmed matches one might suspect the largest segment of 35cMs would be coming from the Noll-Zimmermann group, also being the closest ancestral couple.  However, when looking at shared matches for known Wedding-Rawolle descendants it seems more likely to be a segment on the Wedding-Rawolle line (but this is by no means certain); 

* Assuming my hypothesis regarding the identity of my great grandfather is correct, then we do have documentary evidence that two different relationships would exist between Jennifer and me;

* Whilst we do not have segment data to definitively confirm either of the genetic relationships, the cluster reports provide a much higher level of confidence that both connections to the MRCA's of Noll-Zimmerman and Wedding-Rawolle are also highly likely genetically.

* Where do we now sit on the continuum?  To answer my great grandfather question I need to rely on much more evidence than this match alone, so perhaps it is sufficient for my purposes given I have a lot of other supporting data.  However in other circumstances, it may be quite critical to resolve where each segment was coming from to be able to answer your research question.  

* As a side note, when I first started researching my great grandfather, it was this match that gave me the most heartache, but in the end it was the one that helped the most to finally narrow down the possibilities between two families. 

Match C - Peter:

* In this case we know the relationship is 4th cousin once removed, have a strong paper trail but the DNA evidence was initially low;

* The connection was later DNA confirmed through segment triangulation, on two chromosomes but with the same match;

* At AncestryDNA there are only 6 shared matches with Peter.  Of those, 5 matches have identified MRCA's, 1 sharing my 2GGP's (Coat-Richards) and 4 sharing our 4GGP's (Richards-Coggan) the same ancestors I share with Peter.  Whilst we have no segment data for all but one of these, these matches provide additional evidence to support our conclusions about our genetic relationship, increasing our confidence level;

* The DNAGedcom report places Peter in Cluster 45, it includes 4 of the identified matches for our shared  4GGPT's (Richards-Coggan) including the match who triangulates on both Chromosome 13 and 14;

* Cluster 44-47 are forming a super cluster, with a number of shared matches between the groups.  Peter only has one match shared with Cluster 44, but these are additional clues we can use to build our DNA evidence;

* Cluster 44 contains matches who share my 3GGPs (Richards-Richards) on same the ancestral line as my connection to Peter, via Susannah Richards (no known relation to her husband John);

* The match that Peter shares in Cluster 44 (green arrows) is the same as at AncestryDNA who shares my 2GGP's (MRCA Coat-Richards).  This suggests that the match in Cluster 44 matches me on more chromosomes than Peter, but the one she shares with Peter is a Richards-Coggan segment.  Other segment matches for her in Cluster 44 may have been inherited from John Richards' line, Richards-Lloyd;

* My Coat-Richards match in Cluster 44 (red arrows), shows two shared matches with Cluster 45, which we can hypothesise as likely Richards-Coggan segments.  The first we know is Peter and the second turns out to be the same match that is on GEDmatch and triangulates on Chromosomes 13 and 14.  

* This suggests that our matches in Cluster 45 (who match Peter and the other one in the C13/14 TG) probably triangulate on the same segment area on at least one of those chromosomes.  Whilst these matches have not uploaded to a chromosome site, the additional evidence provided by the DNAGedcom cluster report increases the level of likelihood of the DNA relationship with Peter to highly likely;

* Whilst Peter shares with other matches who share the Richards-Coggan in Cluster 44, there is one he does not share with.  Whilst this match shares with others in the cluster who are Richards-Coggan descendants it suggest their shared segment is probably on different chromosome, not C13/14 where Peter shares.  It should also be remembered that without seeing segment data it could be coming from a different ancestor entirely, particularly in close communities;

* We started out with an individual match to a distant MRCA with a strong paper trail but our genetic evidence was low and we could only mark the relationship as 'Tentatively Confirmed';

* By next using segment triangulation, we were able to mark the relationship as 'DNA Confirmed', but there was only one other match with 'tree triangulation' in the triangulated group;

* As we can also see now, by working between the triangulated segment and the shared cluster data, utilising DNAGedcom cluster reports we were able to gather much more supporting evidence to support the DNA Confirmation, increasing our confidence level to 'highly confident'.

4. WATO Reports

The 'What Are The Odds?' tool from DNA Painter is a fabulous resource that uses DNA and probability estimates to predict potential relationships.  It works best for closer relationships and for predicted probabilities to be more reliable, matches need to be 40cMs or greater.  A low match, or even the absence of a match can correctly rule out hypotheses that might otherwise have been possible.

The first image shows an example of how a half second cousin might fit in to the tree.  This could be used to support a hypothesis regarding potential relationships.  In this example predicted probability is '1' which indicates the relationship is possible, but other relationships are also possible.  More evidence needs to be gathered, both genealogical and genetic, particularly if there was no paper trial.  

The second chart takes this analysis further for more distant relationships on the same ancestral line.  The underlying probability statistics in WATO don't go below 40cMs and distant relationships have many segment matches under that amount. Whilst not useful for probability predictions for distant ancestors, WATO is a great way to plot your matches to give you a visual representation of the size and spread of matches and what additional evidence you have gathered.  I use it as the base for my analysis documentation in powerpoint and add evidence of clusters and triangulated groups to the page.  Notes can also added if there are anomalies that need to be looked at.  

Remember at the distant cousin level, isolated matches are not evidence, just clues.  To provide additional evidence they need form part of either a segment triangulated group, or a shared match cluster.

5. Ethnicity Reports

Ethnicity reports are great examples of supplementary evidence that can help validate or confirm your conclusions regarding relationships, particularly where unique ethnicities are involved.  The following image shows how Rob relates to his highest maternal and paternal match.  Clearly his Serbian heritage comes from his paternal side. 

6.  Y-DNA and mtDNA Tests

For more distant ancestors on either patrilineal or matrilineal lines Y-DNA testing and mtDNA testing is a great way to confirm hypotheses about these relationships.  The following source citations are examples from Wikitree:

• Paternal relationship is confirmed through Y-chromosome DNA test results on Family Tree DNA Tester #1, FTDNA kit # XXXXX, and his 3rd cousin, Tester #2, FTDNA kit # XXXXX, match at a Genetic Distance of 5 on 111 markers, thereby confirming their direct paternal lines back to their most-recent common ancestor who is John Coat, the 2nd great grandfather of both Tester #1 and Tester #2.
• Maternal relationship is confirmed through mtDNA Full Sequence test results on Family Tree DNA between Tester #1, FTDNA kit # XXXXX, Tester #2, FTDNA kit # XXXXX, and Tester #3, FTDNA kit # XXXXX for King Richard III.  The full sequence match confirms their direct maternal lines back to their most-recent common ancestor who is Cecily Neville York, the mother of Tester #3 King Richard III, the 16th great grandmother of Tester #1 and the 18th great grandmother of Tester #2.

Further information and examples of my approaches to DNA confirmation and sourcing in my Family History Program (FTM) can be found in the resources section below.

More Resources:

• DNA Evidence - Summary PDF: Veronica Williams, 2023
• DNA Case Study Template (can be downloaded, end of blogpost): Danielle Lautrec, 2023
• Using DNA Evidence to confirm your ancestors: You Tube Presentation by Veronica Williams, March 2023
• Keeping Track of my DNA using FTM Filters: You Tube Presentation by Veronica Williams, 2022
• Clustering for chromosome analysis:  Veronica Williams, 2021
• DNA Sourcing, using FTM - Practical Guide: Presentation Notes, Veronica Williams, 2021
• Triangulation ISOGG Wiki: 'Tree Triangulation' and 'Segment Triangulation' (scroll down for autosomal triangulation);
• Genealogical Standards: 2019

Building Evidence Summary Table:

Veronica Williams

First published - 9th December 2023

Last updated - 30 January 2024

Using chromosome analysis to find that elusive 2nd or 3rd great grandparent

If you are like me, you have a couple of distant ancestors that are brick walls or where the paper evidence is not being confirmed by your DNA analysis.  Is your paper evidence right, but there are just not enough descendants in the DNA mix?  Or, is there a problem with your genealogy and your ancestor is someone else entirely?

How can chromosome analysis help you with this problem?

This blogpost is aimed at documenting the process to follow in these types of cases.

The plan and things to consider

• Where does the ancestor sit in your tree?
• What DNA test is most suitable, Y-DNA, mtDNA or autosomal DNA?
• How many descendants have tested?
• Have all these testers uploaded their data to a chromosome analysis site? 
• Can you identify additional 'priority' testers that may assist in solving your problem?
• Are you confident that your DNA analysis to date (using the totals shared cMs approach), has confirmed your pedigree back to 2nd great grandparents for all lines?  This ensures you have a solid pedigree base to start using chromosome analysis techniques.
• Have each of the generations between you and the subject ancestor been DNA confirmed?
• How many generations back on 'this line' do your confirmed DNA 'segments' go?
• Can you identify segment data for each generation?

Then take the following actions

• Identify triangulated groups in all of those segment areas;
• Interrogate each of the groups, searching for common names, locations, ethnicities, look for patterns between matches in each triangulated group;
• Build research trees, are there patterns or commonalities between triangulated groups?
• Ensure all 'DNA confirmed' segments can be 'walked back' on each chromosome, for each triangulated group;
• Continue to interrogate all triangulated groups with the aim to connecting them and revealing your shared ancestors.

Not all of their DNA got to you

We need to remember that due to the process of recombination, we don't all inherit DNA from our distant ancestors.  Every generation loses 50% of our ancestors DNA.  That's why it is so important to get as many of your relatives as possible to take a DNA test!  Our genealogical tree is not the same as our genetic tree - we can still be genealogically related to other cousins but share no DNA.  On average, you may have inherited about 3.1% of your 3rd great grandparents DNA - that is, if you got any at all!

How much DNA is available and who should I test?

DNA Painter has great tool called the Coverage Estimator, which can help to identify who is the best person to test to maximise the DNA for your 'target' ancestor.  The following examples show the amount of DNA my family has for my great grandmother Abigail Courtney and her father, my 2nd great grandfather Arthur George Courtney.

Walking back the segments

To start, you need a solid base of DNA confirmed matches that confirm your pedigree.  2nd cousins are ideal as they only share one grandparent with you, they need to have their results on a chromosome site such as GEDmatch, FamilyTreeDNA or My Heritage.  Your goal is to identify the segments inherited from the 'target' ancestor.  With matches at the 2nd cousin level you will be able to identify segments inherited from your shared great grandparents.  In my case they are Edward Roberts and Abigail Courtney.  

It is then a matter of separating the segments inherited from both ancestors to identify those that are on the 'target' ancestors line.  By interrogating all triangulated segments for my Roberts-Courtney line (the line shared with my 2nd cousins) I am seeking to separate out Roberts line matches from Courtney matches.  Then, we need to push each ancestors line back another generation so that we can isolate all triangulated segments belonging to the 'target' ancestor.   

In my case, once I have identified segments inherited from Abigail Courtney, I then need to continue to interrogate those triangulated groups to seperate out the segments she inherited from her mother.  By again separating these out, we should only be left with groups more likely to have been inherited from her father George Courtney (our target ancestor).

As you work through this process it is recommended to continually analyse both your triangulated groups and AncestryDNA clusters.  Finding a 'bridge' match in a triangulated group and also in an AncestryDNA cluster may help lead to other connected matches that may be relevant to your search.  Try to amass as many clues as possible to connect your triangulated group matches to find their common ancestor.  Look for common connections within each group and between groups, the names may not be known to you but they could be clues pointing to your 'target' ancestor.

The follow chart seeks to document my progress in identifying the parents of my 2nd great grandfather Arthur 'George' Courtney.   It can be a long term exercise to push segments back, but eventually you will find that the genetic clues will reveal common surnames, locations or ethnicities that may give clues to to help you progress your genealogical research.

Genetic research principles are very similar to traditional research, you start from yourself and move back one generation at a time.  Just as in traditional research we seek to obtain birth and death certificates for our ancestors, rather than just checking the index; so do we seek triangulated segment data as evidence of shared ancestors, rather than just having matches in common.  This becomes much more important for distant ancestors such as 2nd great grandparents and beyond, where shared cMs are more difficult in pinpointing a relationship given the plethora of possible relationships and the possibility of multiple shared ancestors.

Getting the segment data needed

Often the key matches that will help us solve our mystery are on AncestryDNA and there is no segment data available.  We need to be creative in our requests when asking these cousins to transfer their results to a chromosome site so we can analyse the segment matches between us. Offering to help them with the analysis of their own kits can be a good way to get them engaged.  Alternatively, think about setting up a group project at FamilyTreeDNA that might entice a broader range of testers that could assist in solving your mystery.

My Genetic Research

You can read more about my DNA analysis on my various blogs.  

* My biggest research challenge is my maternal 2GGF Arthur George Courtney.  He has a whole blog dedicated to him, read more on Finding George Courtney c1841.  The Research Summary provides an overview of my genealogical and genetic research.

* In researching George, I managed to identify another maternal 2GGF: read my post  - What is our family name?  Roberts, Baker or Dye?

* Our Irish ancestors are always a challenge due to missing records, but DNA can often piece it together.  My Britton family from Fermanagh are an example.  I have much more to document about this family but these two posts may give you some ideas about what's involved.  Meet Catherine 'Kitty' Britton, thanks to the X chromosome and Reuniting our Britton family, our unnamed Patriarch.

More information

For more information regarding chromosome analysis techniques, refer to the Table of Contents for this blog.

Veronica Williams

25 July 2023

Are you a County Clare cousin - looking for connections in Moyriesk or Rathclooney?

Are your ancestors from County Clare in Ireland?  More specifically are they from the townlands of Moyriesk or Rathclooney, or perhaps nearby parishes of Doora, Clooney, Kilraghtis, Drumcliff, Quin, Tulla or Ruan?

If so, why not join our DNA project as we try and break through our brick wall pedigrees and get clues from DNA matching about our family connections.  Could we be related?

I've been researching my Clare ancestry for some time and you can read more about my known ancestors on my website genemonkey.com.  Known descendants can be viewed using the Wikitree.com links below.

• My 2nd great grandmother Mary Sweeney was b1821, she was the first to emigrate to Australia in 1839 aboard the Roxburgh Castle, along with her brother Terence;
• Her father John Sweeney was born some time before 1795 and can be traced to Rathclooney, County Clare where he lived with his MacNamara cousins;
• Mary's grandfather was Daniel Sweeney and his wife was believed to be a MacNamara;
• John's grandfather, Roe Sweeney died in 1800, but is believed to have lived in Moyriesk, County Clare.  He was a gentleman and his children married into distinguished families, including the O'Connell's.

Sweeney Homestead, Rathclooney 2017

Let's see if we are related!  Please join the Moyriesk and Rathclooney FTDNA project!

The key surnames of interest in this project include McNamara/MacNamara, Sweeney, Hanrahan, Enright, Hehir, O'Connell, O'Donnell, McInerney and McMahon/Mahon.  

Uploading your DNA results to the FTDNA project

If you have tested your autosomal DNA at a different company than FamilyTreeDNA, you can upload your results for free - refer to the Autosomal-DNA-Transfers-Guide.  If you tested at AncestryDNA or another DNA site you might find this blog post by Louise Coakley Genie 1 useful, she explains it better than I could!

Wikitree

As part of the project we are documenting and trying to connect our ancestors on Wikitree.com - a one world tree AND a free family tree site.  The FTDNA project administrators will add the oldest known ancestor to Wikitree and we encourage members to add more of their known County Clare ancestors to the tree.  

You can find other people who have connections to our townlands of interest on Wikitree:-

• Townlands of County Clare
• Moyriesk Townland, Clooney 
• Moyriesk Townland, Doora
• Rathclooney Townland         

We are particularly keen to connect with people who have ancestors identified in one of the following sources for these key townlands:-

Ireland, Tithe Applotment Books, 1805-1927

Griffith's Valuation, Moyriesk, Parish of Doora;

Griffith's Valuation, Moyriesk, Parish of Clooney;

Griffith's Valuation, Rathclooney, Parish of Clooney;

1901 Ireland Census, Townlands of Moyriesk and Rathclooney;

1911 Ireland Census, Townlands of Moyriesk and Rathclooney.

More help

If you need help joining the FTDNA project, or with Wikitree, please do not hesitate to contact me via the contact form on this blog, or by private message at Wikitree.