Friday, December 12, 2014

The Long Journey of your Genome: Part 2

Many of us wonder what path our ancestors traveled through prehistory to the time that pieces of their journey were recorded in various forms of the written word. Those of us who have European female ancestry can use a full mitochondrial test to tell us from which of the Seven Daughters of Eve we descended through our direct maternal lines. However, we must not lose sight of the fact that we may have descended from several of the seven daughters described by Bryan Sykes or even from sisters of the Eve hypothesized in his book. For example my maternal grandmother in a direct umbilical line descended from Helena but my paternal grandmother descended in a parallel line from Ursula. My daughter and son descended from Helena by a very different "umbilical cord" line. Through my daughter-in-law my Dowell grandchildren picked up a second line from Ursula and a line from Katrine through their maternal grandfather. 

Connecting these ancient SNP defined lines with our documented genealogies has been more problematic. Some of us have been able to make haplogroup connections that are meaningful to our genealogical research; but most of us have not. Full mitochondrial databases are still very small compared to both yDNA and atDNA databases so matches are not as common. Also, as I discussed in Part 1 of this series, the amount of information recorded in your mitochondria is minuscule compared to that contained in your chromosomes.

Beginning to read your Big Y Results - Results 

Much of the information that is reported to those of us who have taken the BIG Y test is unintelligible to most of us -- at least at first. FTDNA does not report our BIG Y results in the yDNA section of our My DNA page. Rather, it is in the Other Results section. This is the first indicator that BIG Y results have not yet been integrated with the rest of your yDNA reports. This is most important to remember when you try to understand the place of your own SNPs within the FTDNA. No SNPs have been added to the Y-DNA Haplotree since the inception of BIG Y testing a year ago. 

Only SNPs that had been discovered by FTDNA or GENO2 prior to November, 2013 are included in the FTDNA's current tree. Even some of the SNPs for which you may have confirmed results from individual tests at FTDNA are not reflected on their current tree. These also may not be included in their listing of your confirmed results on your opening my DNA page. For example in 2012 I took an individual SNP test at FTDNA for a SNP named DF13 and was found to be positive. DF13 was then and is now known to be below L21. However, I am still being shown to have a terminal SNP of L21 on my FTDNA report. More recently BIG Y has discovered about thirty more SNPs below DF13. 

There is no way FTDNA could have included those thirty SNP in their tree yet. This is a different kind of exploration. The BIG Y is a voyage into the unknown inner space of our yDNA. However, DF13 was known and I had been tested for it more than a year before BIG Y blasted off and more than a year before the last update of FTDNA's current tree. This is not a criticism of FTDNA's tree as much as it is a caveat warning you not to read too much into it. Probably less that one-tenth of the SNPs on our Y chromosomes, about which we know today, were known at the time FTDNA was putting the current table together. It is going to be a monumental effort to update it.

I think I'll stop now before continuing soon with some hints on how you can begin to interpret your BIG Y results. That is really what I started to do in Part 1 before I decided I needed to give some background first.

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