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J2a-Z482 Jewish

  • 146 members

FAQ

Q. What is a SNP and how can I use them to figure out how I'm related to my matches?

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.  A  SNP occurs approximately every 120-140 years.  Since the Z482 SNP is dated around 4400 years ago, you should have somewhere between 31-37 SNPs that occurred AFTER that SNP.  

Once you discover a SNP that you share with others that occurred within the genealogical time frame (24 generations or ca 11th Century CE), you can start to use SNPs to figure out how you are related to your matches.  For example in our project all of the men who have done Big Y are determined to share a common ancestor who lived around 1100 CE (or 900 years ago).    That suggests that each should have 6-9 SNPs that occurred AFTER their common shared SNP.  If we assume that they had on average 7 SNPs each and a mutation occurred every 125 years, then based on probability we can predict that a mutation may have occurred in 1225, 1350, 1475, 1600, 1725, 1850, and finally in 1975 (assumed year of birth).   Of course SNPs are random and not likely to be so predictable.  

In this project we have 3 men; KING/GUNZBURG, LEFKOWITZ & SOSLAND/KANTROWITZ who share an even more recent SNP that occurred around 600 years ago.  In addition, each has around 5  private SNPs (not shared by any of the other men), that occurred AFTER this shared SNP.  That means that there are ≈ 15 private SNPs whose precise placement on the phylogenic (DNA) family tree is still unknown.  If these mean are close STR matches, you may have some of these SNPs.  You can test the private SNPs of a very close match,  and a positive result will help place your branch on our tree.  Your results will not only assist the entire group by helping to reveal when each of these SNPs occurred, but it will also add a new branch to our tree!   Please contact us for more information if you are interested!   (Click on the result tab above for a diagram and more detailed information).

Q.  I'm already a member of a Haplogroup Project.  Why should I join this one? 

This project is a subset of the larger M172 (occurred around 20,000 yrs ago)  and M67 (occurred around 12,500 years ago)  haplogroup project  because it’s name comes from a SNP that occurred thousands of years after these SNPs.   The Z482 occurred only around 4400 years ago, and so mar MOST of the men who have done Big Y are ALSO  positive for a much more recent SNP that occurred within the genealogical time frame (24 generations).    Remember, our members are primarily Ashkenazi, and MOST Jews did not have surnames this far back.  So for those who can attach their branch to our phylogenic tree within the genealogical time frame this common SNP can be used as a surname surrogate because it is your genetic signature.    We still rely on the larger J2-M67 Project for assistance with more complicated DNA analysis and encourage all of you to also join that project.  

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.  How can genealogy help when we don't know very much about our ancestor?

Among our members is one very notable lineage that can be traced back to Baruch ben Meir ZURICH who was born in 1319 and died in Augsburg.  (His wife Gütlin is the daughter of a direct line male offspring of the famous Kalonymous rabbinical line that can trace its line back to Meshullam born around 780 CE).   So certainly quite a few of our members are expected to be offspring of Baruch ben Meir.  Now Baruch's GGG grandson was Jechiel de Porto who lived in Porto, Mantua, Italy.  From there they moved to Ulm and offspring took both the ULM(O) and GÜNZBURG surnames.    Many of you may have noticed quite a few men on your match list with a variation of the surname GÜNZBURG.  One of them does actually have a DOCUMENTED pedigree that goes all the way back to the de PORTO family of Italy.  (So it is no surprise that we also have several Tuscan matches).   We do have one representative of a GÜNZBURG line that can trace his line to a Rabbi Kallman GINSBERG in the mid 18th Century.  We believe that his SNPs represent this illustrious lineage and you.  So if you are positive for BOTH the Y15241 and Z36098 SNP, you may also be an offspring of Baruch ben Meir ZURICH!!

Even though this project begins well outside of the genealogical time frame, we intend to help all of you attach your branch in the same way we are attaching the closer Günzberg matches. As famous rabbinical lines married into other famous rabbinical families, this isn't likely to be the only famous line on our tree.  The famous  Schneerman/Chabad is aslo a member of this cluster.   In addition, there is some reason to believe that the famous Rothschild banking family may also fit in this cluster, but that's no yet confirmed.  

We will be combining genealogical research like this with results from DNA SNP testing to merge the paper trial with the DNA family tree.  We also encourage genealogical research and will share a gedcom/genealogical file with anyone who is interested in helping us research the paper trail. 

Q.  I've already upgraded to 67 markers.  Should I upgrade to 111 markers or buy the E-SNP Pack? 

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.     In most cases 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-M269 or even R-L23 or  L584,  those are the names of SNPs that  occurred more than 5000 years ago.  Don't even consider testing a SNP that is upstream (occurred earlier) than the J2-Z482  . You can start with this SNP or pick one that is more recent.  Please contact us for advise as it will differ depending on who has already done Big Y, your STR/marker results, and the composition of your match list.

Q.  What is Big Y and how can it benefit me?  

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 nine men who have done Big Y and tested positive for J2-Z482.  (Others have tested positive for this SNP by doing the M67 SNP Panel).   (See YFull  results).  On average each of these men have 8 mutations that occurred after this SNP occurred around the 9th Century.  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 follows:  944 AD, 1088 AD, 1232 AD, 1376 AD, 1520 AD, 1664 AD, 1808 AD and a last mutation  around 1950!   What this means is that if 8 men do Big Y, around 64 new novel SNPs will be revealed that occurred AFTER 800 AD.  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. How can I attach my branch to the J2-Z482 Phylogenic/DNA tree if I can’t afford Big Y?

The nine men who have already done Big Y each have around 7 SNPs that occurred AFTER ≈ 1100 AD.  It is possible for you to test these SNPs at an independent company called YSeq. 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 even at 17.50/SNP it would cost $140 to test all 8 of one person's SNPs.  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.  At that point it will be very inexpensive. 

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 related, but not the same as SNPs.    As a result of  Big Y testing we're learning that there were many more back mutations than previously thought (for example where a 12 changes to a 13 and then goes back to 12).  So while marker testing does help establish relationships, it's proving not nearly as reliable as SNP testing.    STR testing is still the first step in finding matches,  and it is also extremely helpful when trying to determine how a group of men are related to each other.  It is also essential if you want to do individual SNP testing.  The first step in figuring out which SNPs to test is to see which SNPs have already been found in your closest matches. There's a good chance that you'll share some of the same private SNPs with someone who matches you on 66 of 67 of your markers!  


Q. Why does Family Tree DNA show that my Y-DNA Haplogroup is something different from J2-Z482 ? Did my Y-DNA Hapolgroup change?

A.  Your precise haplogroup will only be discovered if you do a test like Big Y or full genome testing.  So your haplogroup will never change, it is just being gradually revealed as more recent SNP mutations become known.  If you look at your match list you will notice that some of your matches show their terminal SNP as M172 and others have been assigments like; M67, L210, or Z482.   But IF you have been invited to join this project, you are  in fact all J2-482.  


The difference in how these SNPs have been assigned may be because one person tested years ago when newer SNPs were still 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.   


J2a-Z489 ca 4700 years before present

|     Z482 ca 4500 years before present 

|     |     Y15222 ca 950 years before present

|     |     |     Y15238 ca 700 years before present


For those members who are positive for Y15222 (also known as Z30375), keep in mind that your match list is only supposed to be composed of men who match within 24 generations.   Since this SNP is predicted to have occurred around the 12th Century, this is within 24 generations.  Therefore all of the men on your match list are probably also positive for this SNP.  


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.  So even the SNP that represents this project may not become officially recognized by Family Tree DNA for quite awhile!  But this project will help make that happen!


Q. What makes J2a- "Jewish"?   Does this mean that I have proven Jewish ancestry?

A. We do not yet know if the patriarch of this group was Jewish or non-Jewish because the J2-Z482 occurred around 4400 years ago.  However, a vast  majority of men who belong to this haplogroup are either Jewish themselves, or are of Jewish descent on their father's line. So for now we can say for certain that if you are positive for the Y15222/Z30375 SNP that occurred around 900 years ago, you are descended from a Jewish ancestor.  Due to a history of persecution, Jews have historically been an isolated population with very little intermarriage and  few converts. Thus, it is overwhelmingly likely that the common ancestor of this haplogroup was a Jewish man. Therefore, being a member of the Y15222 sub-clade 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 we are not yet to say with any certainly if the common ancestor of this group was Jewish.