How to get the most out of your DNA results

1:30 a.m. Tuesday 9 November 2021 (Irish time)/5:30 p.m. Monday 8 November 2021 (Washington time)

by Paddy Waldron

WWW version:

http://pwaldron.info/WSU2021/

YouTube version:

TBA

Outline

• Introduction
• Identity v. Anonymity
• The basic rules for genetic genealogy
• What is DNA?
• Where does our DNA come from?
• Inheritance paths
• The autosomal DNA comparison websites
• How can we use autosomal DNA in genealogy?
• Commercial and marketing priorities
• Combining pedigree charts and DNA results
• Aggregating autosomal match lists and segment data from the different DNA websites
• A case study: the Lynches of Moveen West
• Conclusion: Why you should submit your DNA
• Further reading
  

Introduction

DNA testing is not a substitute for genealogical research; rather the two approaches help to corroborate each other.

1. the oral traditions passed down through the generations;
2. the archival sources used by traditional genealogists; and
3. the DNA evidence that often reconciles both, but sometimes refutes either or both (NPE).

• Is the description of the deceased provided by the informant on a death certificate oral or archival? (Estimated age at death, parents' names, mother's maiden surname, etc.)
• Are family letters and diaries oral or archival?
• Are published or unpublished family histories oral or archival? (e.g. 1991 Cosgrove-Corry by Fr. Peter Ryan at al.)

I once thought of my mother's stories as history. I thought memory was history. Then I became a historian, and after many years I have come to realize that only careless historians confuse memory and history. History is the enemy of memory. The two stalk each other across the fields of the past, claiming the same terrain. History forges weapons from what memory has forgotten or suppressed. Few non-historians realize how many scraps a life leaves. These scraps do not necessarily form a story in and of themselves, but they are always calling stories into doubt, always challenging memories, always trailing off into forgotten places.

Identity v. Anonymity

• There is a trade-off between:
• increasing your chances of finding long-lost cousins and ancestors (and being found by long-lost cousins); and
• maintaining the privacy of your family history research and DNA results.
• If you keep your DNA results or known family tree private, then nobody will be able to find you and you will not be able to find any DNA matches.
• If you want to be found, then you must let your potential cousins see your DNA results and your known family tree.

• Some customers of the DNA companies appear to wish to maintain a certain degree of privacy and anonymity
• Others find it paradoxical that those trying to identify their anonymous ancestors can be so concerned about anonymising their own identity.

The Genetic Information Nondiscrimination Act of 2008 has caused confusion:

• health insurers may not discriminate against people with bad genes by charging above average premiums
• health insurers must discriminate against people with good genes by charging average premiums
• pension providers could discriminate against people with low life expectancy by charging as if they had average life expectancy
• can pension providers charge people with high life expectancy more than if they had average life expectancy?

The basic rules for genetic genealogy

Reveal your birth surname:

Most people inherit DNA with their birth surname, so identify yourself as a minimum by your birth surname with an initial or a title, e.g., P Waldron or Mr Waldron or Miss Durkan.

Reveal the gender of the person who provided the DNA sample:

Valuable additional inferences can potentially be drawn once it is known whether two X chromosomes (chromosomally female) or one X chromosome and one Y chromosome (chromosomally male) are potentially available for comparison.
People who are chromosomally female do not have Y-DNA and are encouraged to recruit their chromosomally male relatives to provide Y-DNA, but they must NOT attach a female name to a male DNA sample, as this causes untold confusion.
Be especially careful not to inadvertently link a male's Y-DNA results with a female's autosomal DNA results at FamilyTreeDNA.com where error-checking does not look for this.

Avoid providing irrelevant information:

Your first name, married surname, adopted surname or marital status reveal nothing about your DNA, so you may keep these private if you wish.

Avoid pseudonyms and aliases:

They reduce the chances that your matches will bother to look at your family tree, contact you or share the information about your ancestry that they have and that you do not have.

Be consistent and avoid unnecessary confusion:

A real example (further anonymised):

• AncestryDNA username: tara1234
• DNA samples from mother and daughter (per email exchange)
• linked to an aunt and niece in a family tree
  
• appear to matches as M.R. (managed by tara1234) and D.C. (managed by tara1234)
• neither of these are the real initials
• the daughter is an AncestryDNA match to her mother's probable 4th cousin, but the mother is not (false negative?)
• only one of the two kits is at GEDmatch.com
• GEDmatch alias and email address both begin with Molly
• Molly is the dog's name
• it took me 300 days after the upload to GEDmatch to associate the AncestryDNA and GEDmatch identities

Keep all your DNA-related correspondence in a single searchable email archive

Use the messaging systems on the DNA wesbites and social media websites only to exchange email addresses.

What is DNA?

• short for deoxyribonucleic acid
• made up of chromosomes and mitochondria, each consisting of molecules of four nucleotides named adenine (A), cytosine (C), guanine (G) and thymine (T)
• represented by strings of the letters A, C, G and T
• laboratories produce a computer file (raw data file) of As, Cs, Gs and Ts from DNA samples
  

Where does our DNA come from?

• When a sperm fertilises an egg, each brings DNA, which is replicated in every cell of the resulting person.

• autosome is short for autosomal chromosome.

Inheritance paths

Y chromosome

Only males have a Y chromosome.
The Y chromosome comes down the patrilineal line virtually unchanged - from father, father's father, father's father's father, etc.
This is the same inheritance path as followed by surnames, grants of arms, peerages, etc.

X chromosome

Males have one X chromosome, females have two.
X DNA may come through any ancestral line that does not contain two consecutive males.
Blaine Bettinger's nice colour-coded blank fan-style pedigree charts show the ancestors from whom men and women can potentially inherit X-DNA.

Autosomes

Exactly 50% of autosomal DNA comes from the father and exactly 50% comes from the mother.
Due to recombination, on average 25% comes from each grandparent, on average 12.5% comes from each greatgrandparent, and so on.
Siblings each inherit 50% of their parents' autosomal DNA, but not the same 50% (except for identical twins).
Similarly, siblings each inherit 50% of their mother's X DNA, but not the same 50% (except for identical twins).
Sisters each inherit 100% of their father's X DNA.

Mitochondria

Everyone has mitochondrial DNA.

Mitochondrial DNA comes down the matrilineal line - from mother, mother's mother, mother's mother's mother, etc.
The surname typically changes with every generation in this line.

• Autosomal DNA is widely used in genealogy.
• Y DNA is used for one name studies or surname projects.
• Targeted mitochondrial DNA and X DNA comparisons can be used to solve more specialised problems.

• Autosomal matches can be related through either parent and through any grandparent, greatgrandparent, etc.
• In principle, Y DNA matches should share the DNA subject's surname.
• In practice, Y DNA matches can have different surnames:
• because the common ancestor lived before the surname era (about 1000 years ago in many cultures); or
• because there has been a surname/DNA switch (a baby boy took his surname from mother, stepfather, adoptive father, or anyone other than his genetic father).
  

The autosomal DNA comparison websites

• GEDmatch.com
• FamilyTreeDNA.com
• AncestryDNA
• MyHeritage.com
  

• from their own laboratory only (AncestryDNA, 23andMe)
• from other laboratories only (GEDmatch)
• from their own laboratory and other laboratories (FamilyTreeDNA, MyHeritage)

So the cheapest way to get into the system and fish in all the gene pools is:

• spit for AncestryDNA and 23andMe
• upload the resulting raw data file to GEDmatch, FamilyTreeDNA and MyHeritage

You are more likely to find confirmed relatives on the DNA comparison websites:

• the more customers the website has
• the better the analysis tools the website provides

The DNA Geek provides regular updates on customer numbers.

How can we use autosomal DNA in genealogy?

• Autosomal DNA can distinguish unambiguously between identical twins and fraternal twins
• Sometimes autosomal DNA comparison can tell us that two individuals are almost certainly full siblings (Group A on the DNA Detectives Autosomal Statistics Chart)
• In other cases it may not be clear whether we are looking at full siblings with below-average shared DNA or half-siblings with above average shared DNA
• Sometimes autosomal DNA can tell us that two individuals almost certainly have one of the relationships in Group B (half-siblings, aunt-or-uncle/niece-or-nephew, double first cousin, grandparent/grandchild)
• Evidence of age and evidence from the other parts of the DNA (X, Y, mt) can be combined with the autosomal DNA evidence to narrow down the possible relationships
• Occasionally autosomal DNA comparison can tell us that two individuals almost certainly have a Group C relationship (first cousin, etc.)
• But generally autosomal DNA comparison can only give us an estimated probability distribution of the possible relationship groups.
• Some DNA companies still give conflicting relationship estimates for the same match (example)
  
• Less informed customers may not understand the difference between an estimated relationship (based on DNA) and an exact relationship (based on a paper trail).

Commercial and marketing priorities

1. separating you from your money;
2. assigning ethnicity labels to percentages of your DNA; and
3. sending you elsewhere for help in identifying cousins and ancestors.

Combining pedigree charts and DNA results

Add DNA information to your genealogy database:

• Beginners may not be familiar with the term pedigree chart, let alone GEDCOM file.
• As soon as you have sent off your DNA sample, you must start recording your ancestors and cousins confirmed by DNA in a database using software like Ancestral Quest.
• You can combine your DNA and your known ancestry to help your long-lost cousins to find you and to find your and their long-forgotten ancestors.
• Use an event field or note tag in your database to track people who are in both your database and the DNA databases.

Add genealogy information to the online DNA databases:

• Export a GEDCOM file containing at least the ancestors of each DNA subject and upload it to all the DNA websites.
• Examples of pedigree charts: from Ancestral Quest, AncestryDNA, ancestry.com, FamilyTreeDNA and GEDmatch.
• For FamilyTreeDNA.com, include in the GEDCOM file any known relatives already in your FTDNA match list and the shared ancestors; FTDNA will use this information to assign other matches to the DNA subject's paternal and maternal sides (example).
• Add your GEDmatch.com kit number to WikiTree.com and GEDmatch.com will automatically display a link to your pedigree chart on WikiTree.

Aggregating autosomal match lists and segment data from the different DNA websites

DNApainter.com is one of several tools for aggregating:

• the match lists provided by all the DNA websites; and
• the segment data provided by all the DNA websites except AncestryDNA.

Example DNApainter profile.

A case study: the Lynches of Moveen West

Episode 1

• Background:
• Pádraig Máire Neans (b. Abt 1826/9, d. 1907) and Tomás Máire Neans (b. Abt 1838/41, d. 1921) are remembered in the oral tradition as two Lynch brothers living across the road from each other in Moveen West. 
• They survived the Great Famine in Moveen.
• Their mother Máire/Mary is remembered as one of two sisters between whom an O'Dea farm was divided - Mrs Lynch and Mrs O'Connell (later evicted?).
• In Griffith's Valuation in 1855, Mary Lynch (apparently widowed, no. 9a) and her son Patrick Lynch (recently married, no. 24a) are listed as occupiers.
• A third Lynch brother, Daniel, went to Connecticut, where his death certificate confirms his parents' full names:

  Daniel Lynch, Newtown, Aug 4, 62, male, married, County Clare, Ireland, Newtown Conn, Paralysis Caused by fall, Farmer, W, Michael Lynch, Mary O'Day, Albert L Schuyler MD
  [3rd last line on each page]

• Daniel is buried in St. Rose's Cemetery in Sandy Hook.
• 20 June 2016: Donation from the diaspora to Clare Roots project "to go towards the test cost for a descendant of the Moveen West Lynch families".
• Around the same time, the Lynch siblings of Sacramento began to show up as autosomal DNA matches to "all the usual suspects" - people with roots on the Loop Head peninsula in West Clare.
• What they then knew about their Irish-born grandfather:

  Because our grandfather, Eugene Lynch, is such a mystery to us we really don't know how to find him. All we have for certain is the 1910 census [lines 39-43]. It says he came over in 1887. The story is this: Eugene married my grandmother in San Jose in 1904 and they lived in Sacramento. He abandoned her and their children in 1909 [sic] when my grandmother was pregnant with my father. We didn't really know anything about him until we started doing this genealogy. We knew [sic] he died in San Francisco in 1917 but were surprised to discover that he was the captain of a schooner at the time.

• 6 October 2016: I uploaded the new recruit to GEDmatch.com and found this triangulation:

  8 8,292,285 54,555,905 50.2 10692 Claire/Ed
  8 17,609,398 38,378,638 27.4 5563 Ed/Michael
  8 17,648,866 37,812,773 26.9 5499 Michael/Claire

• Claire and Ed are fourth cousins, descended from Mrs Lynch and Mrs O'Connell respectively.
• So their 50.2 centiMorgan half-identical region must contain an O'Dea segment.
• Michael is Eugene Lynch's grandson, so Michael must be related to Mr O'Dea (first name still unknown) or Mrs O'Dea (Neans) or descend from both.
• Eugene's surname is Lynch, so he must descend from Michael Lynch and Mary O'Dea.
• Eugene (41 in 1910) is too young to be Michael and Mary's son (their known children have implied birth years 1824-1841).
• Eugene's baptism is not in the parish registers, which survive from 1852.
• Eugene's descendants share too much DNA with other descendants of Michael Lynch and Mary O'Dea for him to be their greatgrandson.
• So he must be their grandson.
• Even this implies a somewhat implausibly large 209.5cM shared between 3C1R - see Autosomal Matrix Comparison and Table of Probabilities.
• 15 November 2016: The Sacramento Lynches arrive in Moveen:

  That day was the highlight of our trip to Ireland, and for me it was an unbelievable gift. I have been wondering and imagining for so long about my grandfather's (and thus my own) origins that I still quite can't believe I went there. It was a profound and moving experience for me. My sister Pat and I speak of it often ... It was magical to us. Both of my parents were from families who didn't stay connected with their homeland, and this journey has really fulfilled a need that I hadn't realized I had. I'll be forever grateful to Tom Kearney for introducing me to you, and to you for so generously sharing your expertise with us.

• For over two years, we swabbed various descendants of the known sons of Michael Lynch and Mary O'Dea in search of closer matches and of further clues, but failed to identify Eugene Lynch's father.

Episode 2

• 8 March 2019: The Sacramento Lynches return to Moveen (Facebook post).
• An epiphany on the road to Moveen - a new hypothesis to be tested: Could Eugene have taken his mother's surname?
• No sign of a Eugene Lynch born to a single mother in the local workhouse.
• We have analysed autosomal DNA matches extensively, but did we ever check Michael Lynch's Y-DNA matches?
• The Y-DNA and the surname both follow the male line, unless there is a surname/DNA switch.
• Not a Lynch to be seen in Michael's matches
• Two Currys out of nine Y-DNA111 matches.
• Four more Coreys or Currys (including an adoptee), none of whom has bought Y-DNA111,  in his top 12 Y-DNA67 matches.
• Surname spellings also mutate, independently of DNA mutations.
• Corey, Corry, Curry, O'Curry, Ó Comhraí should all have the same Y-DNA signature; likewise Lynch, Lindsey, Lynskey, Lynchahaun, Lynchaghaun, etc.
• Could Eugene Lynch really be another Eugene O'Curry?
• Not the parent expected? (NPE)
• The DNA evidence often fills gaps in the traditional evidence, but sometimes refutes it.
• His famous namesake reputedly descends from the O'Currys of Lisluinaghan (see repeatedly evaporated Rootsweb post).
• The Mary Lynch who married Thomas Corry/Curry of Lisluinaghan appears to have been a daughter of Michael Lynch and Mary O'Dea:
• 98.5 centiMorgans shared between a descendant of Daniel Lynch and a descendant of Mary Curry, who could be no closer than 3C1R;
• Pat Corry from Lisluinaghan witnessed the shotgun wedding of Michael Lynch of Moveen in 1882 - were they first cousins? Or even double first cousins?
• Thomas Curry and Mary Lynch had a youngest son called Eugene, baptised in Kilkee parish on 10 Apr 1866:
• "this ancestor has been very elusive";
• he had "previous";
• no sign of Eugene Curry in 1900;
• his wife Ellen Curry née Kelly was a live-in servant in Brooklyn (line 48);
• Ellen's sister Mrs Margaret Blomberg was taking care of Eugene and Ellen's daughter Margaret in Brooklyn also (line 93);
• Eugene's brother Simon Corey was taking care of Eugene and Ellen's daughter Elsie in Newtown, CT (line 96);
• the family lore passed down has always been that "Eugene Curry “went west” to find his fame and fortune and would send for his family at a later date.  He was never heard from again."
• 209.5cM shared between 2C1R makes a lot more sense than 209.5cM shared between 3C1R.
• "The idea of the two Eugenes being one is a bit staggering and mind-boggling" for his descendants, and even for me.
• Further investigation of the DNA matches shared by known Lynch and Corry descendants in different DNA databases has left little doubt that Eugene Curry became Eugene Lynch.

Conclusion: Why you should submit your DNA

• The value of DNA "testing" to genealogists increases dramatically with the number of people from the relevant geographical area and relevant extended family group already in the DNA databases used.
• Submitting your DNA to a database has significant positive externalities for existing and future researchers.
  
• We need to persuade more people to submit DNA samples to the databases for purely genealogical purposes.
• Your descendants will be eternally grateful to you for leaving them your DNA.
  

Further reading

• See here for all the technical details of how and why to upload your DNA data and pedigree charts to the various websites.