The Triangulator

Many genetic genealogists have created tools to use witdirect-to-consumer DNA testing companies.  The list grows every year and allows the DNA tester to view their results and their matches in a wide variety of ways.  One of the basic issues genetic genealogists have is to determine Half-Identical Regions (HIRs) in order to help find the common ancestor(s) they share with a match.

You say WHAT?

Autosomal DNA (atDNA) is the test provided by 23andMe, AncestryDNA, and the one called Family Finder at Family Tree DNA. Although we share 50% of our mother's DNA and 50% of our father's DNA,  atDNA randomly combines with every person so one person does not inherit the same DNA segments as their their siblings, and we do not get equal amounts of DNA from our grandparents, etc.

We inherit 22 PAIRS of chromosomes (one chromosome of each pair comes from each parent) and a set of sex chromosomes.  Males get a Y-chromosome from dad and an X-chromosome from mom.  Females get an X from dad and an X from mom.

Only 23andMe and Family Tree DNA (FTDNA) provide a Chromosome Browser so we can see the segments we share with our matches.  23andMe does have a method of triangulating to determine if matches share the same segment with other matches you have.

At AncestryDNA, you must upload your raw data to GEDmatch, a third-party pool.  Even then, you are only compared with those from any of the companies who have also uploaded their raw data.  That is, you won't see information on the matches at AncestryDNA unless they have also uploaded to GEDmatch.

However, by looking at a Chromosome Browser, you cannot determine if your matches come from your father's side or your mother's side of the family as we get one chromosome from dad and one from mom for each pair of chromosomes.

Until now, DNA testers uploaded their matching segments into a spreadsheet and sorted them by chromosome, start position and end position to determine which matches could share the same segment.  At least three people must be matching on the same segment.  However, this method required an email to the group of three or more to see if all of them matched each other on the same segment (give or take a bit) on the same chromosome.  Those who matched each other on the same segment have a common ancestor and, therefore, share a common ancestor either your mom or dad's side. If someone doesn't match all in the group, that person shares a common ancestor on the other parent's side. This is called determining Half-Identical Regions.  (A Full-Identical Region would be those segments shared by identical twins and there could be some segments which are shared by siblings which match both parents.)

Göran Runfeldt of Sweden has developed a triangulation process using Family Tree DNA.  It has been dubbed The Triangulator.  Remember, this is still in Beta and does work best on a PC with Chrome.  However, Mac users have been able to use it.  See his site for instructions.

Instead of repeating all that others have said, I refer you to the following links which include some blogs on the issue as well as the directions.

Roberta J. Estes' blog:  DNAeXplained at https://dna-explained.com/2017/10/21/introducing-the-triangulator/

Göran Runfeld's instructions at https://dnagen.net/

Haplogroup blog at http://haplogroup.org/installing-goran-runfeldts-family-finder-segment-triangulator-chrome-extension/

Have fun!
Emily

Biggie Changes for Big Y

The Big Y test was launched in November 2013 and is a test for males who have taken a Y-DNA 37, 67 or 111 STR test.  The Big Y refines a tester’s haplogoup as well as contributors to the overall knowledge of the Y Tree by increasing the number of known SNPs from hundreds to thousands. This helps testers find matches who are more closely related in genealogical time with the goal of finding SNPs that are particular to a family group.  Eventually, we will close the gap between genealogical time (existence of records) and ancient DNA. 

The Big Y can be helpful when documentation does not exist.  It has helped genealogists find locations in their former homeland as can be seen in my experience below.

My personal experience:

After having my cousin do a Y-test, I found he matched six other surnames even when I upgraded him to a Y-111.  The wonderful haplogroup administrators suggested that I do some SNP testing which I did.  Then the advent of the Big Y came, and I jumped in.  After having a tester from each of the six names my cousin matched, the haplogroup administrators told me we are part of the Seven Septs of County Laois (Ireland) which existed there in the mid-1600s and at that point my surname Doolin was actually Dowling.

               Well, this is wonderful as I was stuck in Virginia in the mid-1700s and had no ideas if my surname was Scots or Irish as my dad always said we were Scots-Irish.  Also, I had no idea where in either of those countries our ancestors lived.  I realized my lineage could have come from County Laois, but there was a hundred-year difference.

               Last October (2016), my cousin received a match on a Y-37 with a genetic difference of two. I asked Mr. Dowling to upgrade to a Y-111 which he did and then he took the Big Y. He lived in London and had his lineage back to 1795 in County Laois!  So, now we have to discover which of his family (maybe not his direct line, however) may have left Ireland about 1750.  Without the Big Y, I would have had little hope in knowing a probable location of my Doolin ancestors.  Now there is some light.

The news today is that Family Tree DNA is providing a better Big Y experience in a few ways…

On October 10^th the changes in Big Y go live.  At that point Family Tree DNA will be recalculating Big Y matches and they anticipate this to take 5-7 days at which time you will be a page stating “Results Pending.  Once your results are updated, you will be notified, and after the transaction is complete, Family Tree DNA will update you as to when BAM files are available.

So what can you expect?

1.  Update to Human Genome 38

An update from Human Genome 19 to Human Genome 38 which is the most recent version and a more accurate representation of the human genome.  Advantages include:

•  Better mapping of NGS data to the proper location

•  Consideration of alternative haplotypes across the genome

For more information about human genome builds, click here.

2.  Terminal SNP Guide

A terminal SNP Guide allows you to view and filter the branches closest to the tester's terminal branch on the haplotree.

3.  BIG Y Browser

The ability to view your SNP data from Big Y. This will allow you to personally assess all SNP call positions that are being evaluated for matching purposes. This data will be continuously updated.

 Enjoy!

Emily