26Dec15 CopyrightDan)Edwards) 1ourpuzzlingpast.com/geneblog/wp-content/uploads/2015/12/Ancestry... · Found)on)the)AncestryDNA)DNA)landing)page)for)each)kit:) Thegoalof creangmirrored$

26-‐Dec-‐15 Copyright Dan Edwards 1

Collec:ons of family histories (Trees and documents)

Sets of DNA Matches


Successfully Finding Ancestors and Birth Families through Matches’ Trees at AncestryDNA

Depends upon Exploita:on of at least three par:es: 1.  You

•  Your DNA test at AncestryDNA and the resultant match list 2.  A Close match

•  Close cousin’s DNA test at AncestryDNA •  Clouse cousin family history as represented by their public pedigree

3.  Another party •  Match #2’s DNA test at AncestryDNA •  Match #2’s family history as represented by their public pedigree


Fundamentals •  Defini:on of “To Mirror”:

Ø  To copy a pedigree of a DNA match •  That you then use as a proxy for your own pedigree

•  Primary tools: 1.  AncestryDNA DNA match list 2.  AncestryDNA’s Shared Ancestor pedigree matching system 3.  Ancestry.com tree soQware

•  Usefulness Ø  Depends upon how many of your cousins have tested

•  AncestryDNA database of tests currently favors US colonials but that is changing as AncestryDNA offers their product in other countries.

Ø  Perseverance is important as one may have to wait a while un:l a revelatory DNA match appears.

Note that Ancestry soQware capabili:es

may change at any :me


Note: this intensive use of con:nually connec:ng and disconnec:ng mirrored pedigrees in an aVempt to use the shared ancestor hints to discover bio-‐families is an “off-‐label” use of the system as we’ve not seen AncestryDNA discuss or encourage this.

Found on the AncestryDNA DNA landing page for each kit: The goal of crea,ng mirrored pedigrees for an AncestryDNA kit is to generate these Shared Ancestor Hints

Knowing What You Bought at AncestryDNA

The number of “4th cousins” (really meaning es,mated 4th to 6th cousins) or closer is based ONLY on DNA matching and has nothing to do with aGached trees.

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Also found on the landing page is the link to the “ethnicity” es9mate page. We are ignoring those inten9onally.

Algorithm For Exploi:ng Mirrored Pedigrees Ø  Create a Private, Non-‐searchable tree on ancestry.com for research, hereaQer referred as

your research tree. Ø  You only need one such tree as any ancestry.com tree can contain many thousands of people and you can connect

and disconnect individuals to each other as oQen as you wish; you will want to maintain a large database of possible rela:ves anyway and it is easier to manage one large database of possible rela:ves than many different databases. So if you are going to mirror, for example your closest 25 matches you don’t need 25 trees – just one tree (i.e. database) will do.

Ø  Edi:ng individuals in an ancestry.com tree and manipula:ng trees: see the many Ancestry.com videos for direc:ons. Ø  Make your specula:ve trees non-‐searchable so that other ancestry.com users won’t stumble across your tree and

incorporate your specula:ons into their trees.

Ø  Start with your closest match of unknown rela:onship to you, who has a pedigree aVached to their test of at least a few genera:ons. Ø  If a match doesn’t have a pedigree aVached obviously there is nothing there to mirror (but you might s:ll find it

useful to use the Shared Matches capability of AncestryDNA on such a match.) Ø  If you have a close match you want to research and they only have aVached a short pedigree, you can research their

ancestors and if their families are well documented you can build back their pedigree and use it for your own pedigree. However, be aware that there are many poorly researched trees at ancestry.com and as you build pedigrees look for suppor:ng documenta:on.

Ø  Copy your match’s pedigree (star:ng with your match as the root) to a reasonable depth (to 3rd or 4th great grandparents as a minimum is oQen needed), Ø  by entering the individuals from your match’s pedigree into your research tree and connec:ng them to each other as

shown in your match’s pedigree chart. Ø  Start with the direct lines – ie. the parents, the parents of the parents, and so on. Later you will probably want to go

back and add in other individuals (siblings and spouses) depending upon whether you discover a direct line ancestor is common to other kits in the AncestryDNA database.


Algorithm For Exploi:ng Mirrored Pedigrees (cont.)

Ø  AVach your AncestryDNA kit to the root person (your match’s posi:on in the mirrored pedigree.)

Ø  Wait un:l the AncestryDNA Shared Ancestor matching system does its work in comparing the pedigrees of DNA matches (this can take a couple of hours to a couple of days.) Ø  On occasion the Shared Ancestor Hint system can appear to get stuck, not changing shared ancestors hints

even though you’ve changed the person to which you’ve aVached your DNA kit. You may have to detach your kit and wait a couple of days un:l all the previous shared ancestor hints clear out, and then aVach your kit to your new root person.

Ø  If Shared Match hints are created (which will be reported to you on your DNA landing page), view each match flagged as such for the common ancestors. Ø  If for any given mirrored pedigree you get more than one shared

ancestor hint to the same couple, you ought to try the “second step” outlined later.

Ø  Repeat the mirror pedigree crea:on then for the next closest match on your list for whom you don’t know the connec:on.


Shared Ancestor Hint Appearance on a DNA Match Page


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“You” as the person whose pedigree you mirrored.

A DNA match in your match list who has a family tree aVached to their kit.

Ancestors your two matches (the one you mirrored, and another one) share that may be your ancestors too.

If the match is not contactable use the “Shared Matches” capability (discussed later) of AncestryDNA to iden:fy common rela:ves who might be contactable.

Ø  “Possible range: Parent, Child -‐ immediate family member”

Your parent or sibling is in the database! Mirroring not necessary if your goal was to find such person.

Ø  “Possible range: Close family -‐ 1st cousins” Your half-‐sibling, aunt/uncle, or grandparent is in the database! Mirroring might provide more informa:on but contact is the most direct way to your final goal if you are seeking birth family.

When To Use Mirroring with Matches

Ø  “Possible range: 1st -‐ 2nd cousins” You have a first or second cousin, or half-‐first cousin, or half-‐aunt/uncle, or grand aunt/uncle, or a double 2nd cousin, in the database. Ø  However, unless you happen across a family group who have tested many of

their family members, you are unlikely to get shaky leaf hints on grandparents. Great grandparents are more likely to be found.

Ø  If you are lucky to have many such close matches with aVached pedigrees, you can some:mes see their common ancestors just by visual inspec9on of their pedigrees.

The ul:mate usefulness of mirroring any given match may depend upon the closeness of the match whose pedigree you wish to mirror.

Per es9mated (by AncestryDNA) kinship categories:


When To Use Mirroring with Matches (cont.)

Ø  “Possible range: 2nd -‐ 3rd cousins” Your DNA match is a cousin not too close and thus may not have personal knowledge about your birth family, but you share at least one common ancestor not too long ago. •  Most recent common ancestor is likely post Civil War (in the USA) or an immigrant late

enough to be found in immigra:on documents. Ø  “Possible range: 3rd -‐ 4th cousins”

Your DNA match is a cousin not too close; these are challenging but workable in finding family groups which include your ancestors. You probably have many biological cousins in this kinship range in society at large (even if not yet DNA tested) so you are likely to have some in your match list but it can take considerable work doing descendency research to narrow down your birth family with these kind of matches.


Matches of this distance are oQen produc:ve for doing genealogy work because the shared ancestors lived during a period when it is likely they leQ some documenta:on that can be found. Discovering shared ancestors at this depth can reinforce hypotheses regarding possible closer rela:ves.

Pedigree Chart, of moderate depth and high completeness, Mirrored from a close match, illustra:ng shared ancestor hints

Close match you mirrored

parents grandparents Great grandparents 2nd great grandparents 3rd great grandparents

Your DNA kit aVached here

Typical 3rd cousin match

Your possible ancestor Your possible ancestor


When To Use Mirroring with Matches (cont.) Ø  “Possible range: 4th -‐ 6th cousins” Ø  “Possible range: 5th -‐ 8th cousins”


In both of these cases there are significant challenges arising from: •  Randomness of DNA inheritance

•  We can have matches from very distant cousins who, by random, might share an expected amount of DNA similar to 4th cousins.

•  We can have 3rd cousins with whom we share no significant chromosome regions and thus are not “matches”, or, are matches but share such small chromosome regions that they appear as distant cousins.

•  Accumula:on of NPEs/adop:ons through :me •  NPE rates of 1% to 2% per genera:on means that the paper pedigrees

connec:ng many 5th cousins are not the connec:on via DNA. •  Significant numbers of non-‐documented adop:ons during :mes of wars

and famines, and plagues. •  Inaccuracy of deep family trees

•  Records are oQen missing and family histories are inferred •  Genealogy scams of the past

Common Errors and Pinalls •  Presump:ons: –  Assuming the shared ancestor hint person is your ancestor

•  Could be your cousin –  Be aware of “half”-‐rela:ve possibili:es

•  In an ancestral couple on which you have a shared ancestor hint you may be related to only one of the two.

•  Tree mismanagement –  Duplica:ons of too many trees

•  Solu:on: Use a single database –  Not making the research tree private and non-‐searchable

•  AVaching your DNA test to long dead people •  Using too distant of matches –  Solu:on: Use “Extremely High” probability matches at AncestryDNA – these are your closest rela:ves


Ø  What to do when one thinks one has found an ancestor: Create a Descendant chart for two genera:ons

Ø  Spouses of children of ancestor Ø  Grandparents of spouses

Second Steps and Special Cases


Use mirroring technique on various grandchildren of ancestor to find through which child of a shared hint ancestor you may be descended.

This amount of depth in a mirrored tree is not necessary and can be misleading

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Your mirrored match

Second Steps and Special Cases (cont.) Ø  Large numbers of “3rd to 4th cousin” matches:

–  If you have very many matches es:mated to be 3rd to 4th cousins then one or both of your parents may come from endogamous popula:ons •  Ashkenazi Jews (AJ) •  Island popula:ons

–  Hawaii and Polynesia –  Puerto Rico

•  Very many genera:ons of cousin marriages combined with rela:vely small founding popula:ons leads to many small but sta:s:cally significant shared chromosome regions between any two individuals in these popula:ons, making one seem like a 4th cousin to everyone in the popula:on.

•  Mirroring and cousin network methods may be of limited use •  Possibly Y chromosome and mitochondrial DNA matching methods may be required

Ø  Shared ancestor hints may appear on several different lines in a mirrored pedigree: –  Mul:ple cousins: double first cousins, double 2nd cousins, combined 2nd and 3rd

cousins, etc. •  You have ancestors who married siblings from the same family, or married cousins, and this may occur

more than once on any of your lines. This is not uncommon. •  Our ancestors tended to find mates within their small communi:es, leading to family trees being very

interwoven. •  This is one reason why you want to keep a single database (i.e. a single research tree) as you may have

to research an en:re liVle community and families may be mul:ply connected!


Addi:onal Techniques For Data-‐Mining Matches’ Pedigrees

Ø  Networks: Crea:ng sets of individuals, each of whom may match only a subset of the en:re set. Ø  DNA Circles/ NADs Ø  Custom made networks

•  Using an In Common With tool Ø  Segment mapping: For each autosome and the X chromosome,

using cousin matches to assign por:ons of chromosomes to ancestors. This method requires going from the known to the unknown

•  Suited beVer for those who already know some of their ancestors and have iden:fied tested cousins.

Ø  Jeff Snavely’s Chrome extension Ø  Harvests ancestors from matches. Ø  If used then mirroring may be redundant.


Networks of Matches: Of DNA Circles and New Ancestor Discoveries (NADs)


The “New Ancestor” -‐ If not a direct line ancestor, then a cousin or a spouse of a cousin. In some cases he/she will be an ancestor of a spouse of a cousin.

If you mirror the pedigree of one of these matches then the person at the center of the NAD (in this case James Turner) will show up as a shared ancestor hint for that pedigree.

View the Ancestry Academy Course for More informa:on on DNA Circles and NADs

The person to which the AncestryDNA Kit is aVached but who does not have the NAD target ancestor in their current pedigree.

Sample NAD:

Why use Mirroring if AncestryDNA has NADs?

Ø NADs exist because DNA Circles exist. –  Every NAD in the system is a DNA Circle for at least a few other

people. –  If an ancestor is not the center of a DNA Circle somewhere in the

system, then there will be no NAD for others to exploit.

Ø  Even though mul:ple instances of an ancestor may exist in the AncestryDNA aVached pedigree database, a DNA Circle s:ll may not be created: –  The requirements for the crea:on of DNA Circles may be too strict

•  Spelling varia:on in names can keep the DNA Circle algorithm from iden:fying common ancestors.

–  Database dynamics: people are constantly changing pedigrees to which they aVach DNA kits, so DNA Circles with cri:cally few members may disappear easily.


Custom Networks of Common Matches


“Shared Matches” Tool provided to find matches In Common With with any match in your list. Found on each of your AncestryDNA match pages:

Returns a list of DNA matches of confidence (to you) of “Extremely High” and “Very High” (and thus excluding matches only “High”, “Good”, and “Moderate”) who also are a DNA match to your currently viewed match.

That these cousins cluster together is sugges:ve that they share ancestors, or their ancestors inter-‐married.

Keep a spreadsheet for cousin-‐clusters. Diagramming the connec:ons may help visualize the families.

Chromosome Mapping Ø  As AncestryDNA does not currently offer shared region (“segment”) data between

matches, chromosome mapping of matches at AncestryDNA is not possible unless one transfers their genotype data to 3rd party sites (gedmatch.com, or FTNDA.)

Ø  Chromosome mapping works by going from the known to the unknown, thus requires knowledge of shared ancestors with a known cousin.

Ø  For a discussion of these techniques and tools see: hVp://blog.kiVycooper.com/tag/chromosome-‐mapping/

Ø  If one does not know at least a few of their biological predecessors then one cannot do chromosome mapping. However, one may be able to benefit from the work of others. If you have a match who has successfully mapped, to one set of their ancestors, the shared chromosome region between the two of you then you know that ancestral couple are your rela:ves, possibly your direct line ancestors, but at least your cousins.

Ø  Overall, it is a powerful technique but requires a great amount of work.


Crea:ng A Large Database of Ancestors of Your DNA Matches

Ø  As each of your AncestryDNA match pages has a list of pedigree entrants for the DNA match of that page, if the DNA kit is aVached to a tree, it is possible to collect these ancestors into a large database.

Ø  Extraordinarily laborious to do this manually, though technically possible. Ø  A Google Chrome browser extension has been developed to automate the

process: “AncestryDNA Helper” (search for that name at the Google store.) –  Check the Yahoo group: hVps://groups.yahoo.com/neo/groups/AncestryDNA_Discussion/info


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Same ancestor found in several pedigrees from different families

Several different DNA kits

Once a database of the ancestors from thousands of matches is compiled, common ancestors of matches become no:ceable (in this case a 3rd great grandfather):

Crea:ng A Large Database of Ancestors of your DNA Matches (cont.)

Ø  However, one must s:ll be careful not to assume someone occurring mul:ple :mes in the pedigrees of your matches is your ancestor. They could be a cousin!


Same ancestor found in several pedigrees from different families

Several different DNA kits

•  Here an ancestor of several matches shows up in a match list, but in this case the ancestor is a 2nd great grand uncle! :

In this case, it took researching the siblings of this gentleman and no:cing more matches to his father (on previous page) and that there were matches to his siblings too, to be sure this Theodore was an uncle, not a direct line ancestor.

Conclusion: Strategies Ø  To maximize poten:al of AncestryDNA Shared Ancestor hints we need:

Ø  Many individuals to do autosomal DNA tests Ø  Many of those tested need to have

Ø  Developed family histories Ø  Be willing to share their pedigree publicly

Ø  This is a collabora:ve effort


Ø  The Pedigree Mirroring technique allows one without knowledge of their biological ancestors to make use of the AncestryDNA Shared Ancestor Hint system.

Ø  Discovery of a common ancestor with more than one match combined with descendant research gives one a list of candidates for close family members.

Ø  Addi:onally tes:ng of one or more of these candidates can result in the discovery of a birth parent/family.

Encourage openness in the genealogy community

Encourage people to test

Documents

26Dec15 CopyrightDan)Edwards) 1ourpuzzlingpast.com/geneblog/wp-content/uploads/2015/12/Ancestry... · Found)on)the)AncestryDNA)DNA)landing)page)for)each)kit:) Thegoalof creangmirrored$