Showing posts with label SNP S1026. Show all posts
Showing posts with label SNP S1026. Show all posts

Tuesday, September 22, 2015

Tested 67 ySTR Markers? Now What?



You have tested 67 ySTR (short tandem repeats) markers and you still want to learn more. What's a guy to do? If you have several closely bunched matches at that level, you may want to upgrade your test to 111 markers to see if that will sort your matches out a bit. On the other hand you may be ready to start exploring your SNP (single nucleotide polymorphic) trail down from prehistory to you.

If you have tested at FTDNA, you already have been given an estimate of your haplogroup (ancient clan). 


In this example the suggested haplogroup is R-M269 

One way to look at your haplogroup is as an exit number along the great SNP inter-eon freeway down which your genome has been traveling for thousands of generations. In this case your ancestor had a permanent change (SNP) in his genetic migration at exit R-M269. Since that point all of his male descendants have continued to carry that same SNP to document their journey down to you.

However, this SNP is probably carried by millions of men living today. If you want to document your migration path more precisely, you will have to become a SNP chaser.

If you are a novice ySNP chaser, you will have to reorient your thinking a bit. When you read the results of a 37 marker, 67 marker or 111 marker test, you are used to seeing the number of STRs that occur at given locations along your genome. Generally these are numbers like 10 or 28. These results were used by the lab to group you with other men who have identical results on most of the markers tested. It takes identical results at a group of locations (e.g. 37 or 67) considered simultaneously to identify men who may be closely related in genealogical times. Generally the more exact ySTR matches two men share, the closer they are to their common paternal ancestor. The process is somewhat like a census conducted by going to 37 or 67 houses (predefined genetic locations) and counting number of ySTRs that reside there. It is a census of STRs that live there currently.

With ySNPs we are documenting a journey that is recorded in a diary of all the branching points that have occurred in the past. It is like driving from coast to coast and listing in sequential order each of the interstate exits you took. In the example above the most recent branching point the lab was able to estimate was exit (SNP) R-M269 which first showed up in the genomes of that man's ancestors many thousands of years ago.

If you would like to get some idea of where other important branching points of your genome may have occurred without spending more money on testing here is one technique:


Click on "Advance Matches" shown in the illustration above.

On the following screen select "Y-DNA67" and then click on "Run Report":

A results page similar to the one shown below will appear. 

This page has been truncated for privacy of  the men reported.
In all likelihood the SNP trails of all of these men have been identical down to the last few millennia, they show a wide variety of results in the "YDNA Haplogroup" column on the left. These differences reflect the depths of testing these men have gone through. Some of them have had no specific SNP testing at all and are predicted to be M269. Others had had some level of SNP testing completed and have been advanced to exit R-L21 -- the most common male haplogroup along the Atlantic coast of Europe. Some have taken the BIG Y test and been assigned the more precise haplogroup R-S1026. In this example it is highly likely that all of these men belong to this later classification but only testing would verify that conclusion. The relatively close 67 ySTR results (right column above) allow me to make that prediction.  

At present SNP chasing is really in its infancy. A vast majority of the SNPs we know today have been discovered in the last two years. We are still working to find the exact location and sequence for many of them. In some ways our knowledge today would be like getting a SNP passport with several dozen stamps on it but in random order. We know that our genomes passed through all those points but are still trying to decipher in what sequence that journey occurred. As more men are tested and we can document where they exited the main SNP trail, we can refine our chronology for all of us.

The above exercise should give some sense of direction for further SNP chasing research to trace the path of your ancestors down into the genealogical age. At present R-S1026 is the most recent checkpoint FTDNA has added to its published SNP Tree. Most estimates are that R-S1026 has been around for about 3,500 years. The each of the men in the above chart who have confirmed their R-S1026 status through BIG Y testing now have three dozen or so SNPs more recent than R-S1026 stamped on their passports. Some of those SNPs are shared with others and a few of them are unique.

In my next post I will discuss three separate testing strategies for exploring your SNP trail.


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.