Q. What is a SNP and how can I use them to figure out how I'm related to my matches?
A. SNP is short for single nucleotide polymorphism. They are the most common type of genetic variation among people. Each SNP represents a difference in a single DNA building block, called a nucleotide. For example, a SNP may replace the nucleotide cytosine (C) with the nucleotide thymine (T) in a certain stretch of DNA. When this occurs it is a mutation (or change in your genetic code) that we can then use to determine how people are related to each other. Since these mutations occur in individuals, that means that people who share the same SNP ultimately inherited them from the same individual—a common ancestor.
A SNP occurs approximately every 120-140 years. This suggests that the common ancestor of Y6923 lived sometime around 350 CE. Furthermore, as you can see from the tree on the results page, SNPs below Y6923 have been discovered from individual Big Y tests, and these SNPs represent sub-branches of Y6923 whose common paternal ancestors lived as recently as 1100 to 1700 CE. You may have some of these SNPs, and if you do that will not only help the entire group by helping to reveal when each of these SNPs occurred, but it will also help place your line on the phylogenic tree.
Q. I'm already a member of a Haplogroup Project. Why should I join this one?
A. This project can be considered a hybrid surname haplogroup project because it’s name comes from a SNP that occurred within (or slightly outside) of the genealogical time frame. Because MOST Jews did not have surnames this far back, this SNP can be considered a surname surrogate because it is your paternal genetic signature. Family Tree DNA considers the genealogical time frame to be 24 generations or around the 11th Century. So this project is open to all of the men who appear on your match list. We still rely on the larger E-M35 project for assistance with more complicated DNA analysis and encourage all of you to also join that project as well.
If you're in the Jewish E Project it won't be of much use to you because it is a starter project to figure out where you belong, and that has already been determined. The Jewish E Project is also too large and encompass other sub-haplogroups that are not related within the genealogical time frame. Furthermore, the Jewish E project is no longer active, and members of this project who joined more than five years ago still remain unsorted. Our project is small enough to give you personal attention.
The primary advantage of belonging to this project is because we offer BOTH DNA expertise and genealogical expertise. Most men in this group do not have information on their "Y" ancestor prior to the 18th Century. But there are some Jews who do have family trees and surnames that go back as far as the 12th Century—even possibly members of this group!
Q. Why does Family Tree DNA show that my Y-DNA Haplogroup is something different from E-Y6923? Did my Y-DNA Hapolgroup change?
A. Haplogroups are named after SNPs, and in many cases Family Tree DNA makes a prediction about your haplogroup based on your Y-chromosome STR results. Since SNPs are mutations that occur in individuals, and thus indicate common descent, haplogroups are not mutually exclusive. Take a look at the tree provided on the results page. We are all members of Haplogroup E-Y6923, but as you can see, that haplogroup is a sub-haplogroup of E-L791. Thus we are also all members of E-L791 as well. And while L791 has more sub-haplogroups that do not appear on this tree, those groups would also belong to E-L791, but not E-Y6923.
So your haplogroup will never change, it is just being gradually revealed as more recent SNP mutations become known. Your precise haplogroup will only be discovered if you do a test like Big Y or full genome testing. If you look at your match list you will notice that some of your matches show their terminal SNP as L791 and others have been assigned L117 or M34. But in fact you ARE Y6923. The difference in how these SNPs have been assigned may be because one person tested 10 years ago when a particular SNP was not known, or it may be because one person has paid to test for a specific SNP. Unfortunately, Family Tree DNA does not update predictions as new SNPs are discovered, so a father's prediction will be different from his sons if they were tested years apart. Still you are all the same! Keep in mind that your match list is only supposed to be composed of men who match within 24 generations. Our SNP has a predicted date of 400 CE. So that means that you MUST share all of the following SNPs.
M34 ca 15200 years before present
| L791 ca 5700 years before present
| | Y4971 - ca 5100 years before present
| | | Y6923 - ca 1650 years before present
Also, keep in mind that just because someone does Big Y doesn't mean that their SNPs are available for purchase at FTDNA, or even recognized by the genetic community. A SNP has to be found in a certain number of individuals before it becomes "officially" recognized. While, Y6923 is available for testing through Family Tree DNA, it is not on their official tree. But this project will help make that happen!
Q. Should I upgrade to 67 or 111 markers, or buy the E-SNP Pack?
A. Neither would be very helpful right now. Marker upgrades may be helpful in determining how closely you are related to your matches. However, if it’s a choice between upgrading STR or doing SNP testing you’re much more likely to get more bang for your buck by investing in SNP testing. However, currently, the SNPs included in the Family Tree DNA SNP pack occurred thousands of years ago and are of no use to you. So please check with any of us before purchasing a test that may be of no benefit to you. Remember, just because FTDNA reports your haplogroup as E-L117, those are the names of SNPs that occurred more than 14,000 years ago. Don't even consider testing a SNP that is upstream (occurred earlier) than Y6923.
Q. What is Big Y and how can it benefit me?
A. Big Y is a direct paternal lineage test that looks at 12 million locations on the Y Chromosome. Big Y is able to detect new branch markers that are unique to your paternal lineage, surname, or even you. Because a SNP will mutate approximately every 144 years (one of the nucleotides A,C,G or T will change), the age of a SNP can be calculated, and the more men who do Big Y, the more accurate this date becomes.
In this group we have several men who have done Big Y and tested positive for Y6923. (See YFull results). And so far we have discovered 3 sub-branches representing men who share a common SNP downstream from Y6923. Different companies use different mutations rates, but if we assume that one SNP mutates every 144 years, then additional “downstream’ mutations may have occurred as follow between 1100 and 1250 CE, and one as soon as 1700! What this means is that the more men do Big Y, more new SNPs will be revealed that occurred AFTER 750 CE. When two or more men share a SNP, that SNP becomes a common SNP and its position on the SNP tree can be determined and a date can be predicted. But as you can see that leaves scores of SNPs that have been found in some of your matches. If you also do Big Y you will be able to pull out even more of these SNPs, get them dated and contribute even more of your own novel SNPs.
This group is still in need of more Big Y, some men are better candidates than others. For example if one of your very closest STR matches has already done Big Y your contribution will be less than if you have no close matches who have done Big Y. When you have a super close match who has done Big Y there are some very inexpensive ways to attach your ancestor to the SNP tree without doing Big Y.
Q. I just got my Big Y Results. What is the next step?
A. The next step is to get your results analyzed by haplogroup administrators and even outside sources. Most of the men in this project have sent their Big Y results to a company called YFull for both analysis and inclusion in their experimental Y Tree. In order to do this, you will need to send them your BAM file. However, this file needs to be requested from Family Tree DNA. You can request it by clicking on the "contact us" link at the bottom of the page. On the next page select "Open Request". The fourth item down is "Big Y BAM Request". Select this and just say that you want your BAM file.
In about 4 working days you should be able to access this BAM file. You can find it on your Big Y result page in the top right hand corner. Select "Download Raw Data". Next select "share BAM file". After that you will need to copy the link in order to share it. The administrators in the E-M35 Project will want your BAM file. In addition, we hope you will also send it to YFull. YFull will not charge your for adding your results to their experimental tree, but it will cost $49 if you want access to your results. You do not get charged until your results are ready.
Q. How can I attach my branch to the EY6923 Phylogenic/DNA tree if I can’t afford Big Y?
A. The men who have already done Big Y each have around 5 SNPs that occurred AFTER 750 CE. It is possible for you to test these SNPs independently. Depending on interest in this group, we could look into putting together our own SNP panel. You also can order any of these SNPs at a cost of $17.50 per SNP. By testing positive for one of these SNPs, you will add yourself to the SNP tree. Of course, this is more of a "guess and check" approach, but as we learn more about each of these SNPs and are able to place and date them there will be much less trial and error involved in figuring out what to order.
Q. I've already taken a Y-Chromosome test through Family Tree DNA. Why should I take more tests?
A.Most of you have taken one of the basic Y-DNA tests which only test Short Tandem Repeats (STR). STRs are a little different than SNPs in that they represent a certain section of DNA that tends to repeat itself often. These tests are very useful to determine relatively close relationships, but they aren't good for establishing the tree shown above because they tend to mutate back and forth, and are therefore less precise.
In many cases, an STR test is the best test to take. Not only does it allow you to find close genetic matches, it can also be used to predict your SNP by comparing your STR results to others who have also taken SNP tests. If it wasn't for your STR test, you would not have been identified as a member of Y6923! However, STR tests can only go so far and for the type of research we are looking to do in this project, SNP tests are also necessary. Projects like this one are useful to help you decide which "upgrade" tests are necessary and which are not.
Q. What makes E-Y6923 "Jewish"? Does this mean that I have proven Jewish ancestry?
A. The simplest answer to this question is that E-Y6923 is Jewish because the vast majority of men who belong to this haplogroup are either Jewish themselves, or are of Jewish descent on their father's line. Due to a history of persecution, Jews have historically been an isolated population with very little intermarriage and very few converts. Thus, it is overwhelmingly likely that the common ancestor of this haplogroup was a Jewish man. Therefore, being a member of this haplogroup can be viewed as confirmation that you have Jewish ancestry on your patrilineal line (i.e. father's father's father's father, etc.). However, it does not say anything about the rest of your ancestry.