Question about genetic groups on My Heritage & Ancestry #dna #sephardic


joelle.meyer24@...
 

Hello all
One of the question which comes often is how far DNA can trace a portuguese ancestor at least 8 generations ago ?
I remember having read that it is not possible but I cannot put a hand on the article.
In other terms do you all agree that if I am 100% askenazi this does not mean that at 8 th generation away my ancestor could not have been 100 % descending from jews who escaped Portugal after the inquisition ?
Thanks 
Joelle Meyer from Paris, France
Focussed today on my ancestors from Emden and Groningen region and in particular Portuguese ancestor (Henriques, Mousaphia line from Gluckstadt and Hamburg)


Sally Bruckheimer
 

You get 50% of your DNA from each parent - 50%
They each get 50% of their DNA from each parent - 25%
Same for ggrandparents - 12.5%
Same for 2nd ggrandparents - 6.25%
Same for 3rd ggrandparents - 3.125%
Same for 4th ggrandparents - 1.563%
Same for 5th ggrandparents - 0.78%
Same for 6th ggrandparents - 0.39%
And so on
 
But you  can't tell anything more than 2nd ggrandparents from noise.
 
Sally Bruckheimer
Princeton, NJ
 
I put a chart in Files that has Relationships and DNA %
 


Vivs
 

Hi 

  Autosomal DNA is unlikely to be helpful 8 generations back(or at least extremely challenging)  for anyone.  For someone with an endogamy issue like Jewish DNA typically is, there's not a lot of hope there. 

However, you might get someplace with YDNA, depending on having an appropriate male to test in the line or lines you are looking at. 
--
Vivs Laliberte
www.theOCGG.com

Orange County, California


R Jaffer
 

With luck of the DNA lottery, availability of historical records that allow you to create a tree, and knowledge of women's birth names if the match is through a woman, I have learned that it is possible to find cousins up to 5th cousins once removed. I have one Jewish match that I can prove to the mutual ancestor being my 3rd gg born c 1775 and died in 1840 in Khotin, Bessarabia. On FTDNA my match shares 105 cM with a long string of 43. For the same person MyHeritage reports 85.9 cM with a long string of 42.7 cM. Jewish matches are generally limited to about 4th cousins due to the lack of surnames before c 1800 and a lack of historical documents. 

For the Christian side of my family which arrived in the US in the 17th and 18th centuries and for whom there are surnames in that time frame, I have two matches to the same MRC ancestor, a 4th gg who lived c1705-1767. For one match I share only one segment, but it is 105 cM long. For the other 5th cousin once removed we share only 45 cM with a long string of 16 cM. I have other matches to this same gg, but early documents, i.e. birth/baptism, are missing to prove the direct descendancy and our relationship. I also have a paper trail for a cousin who shares my 5th gg who lived c.1720-1783, but that is only because they were Quakers for whom there are great marriage and birth records available online. We share only 32 cM and a long string of 14 cM. I only found this cousin because he had listed an extensive list of surnames with places, and I was searching based on surnames rather than shared DNA or length of segments.

If historical records are available for your family and you have an extensive tree, test cousins or aunts and uncles to help with the DNA inheritance issue for better luck in finding cousins.

Roberta Jaffer
Massachusetts
searching for Weinberg, Freedman, and Konop from Khotin District of Bessarabia, now Moldova and Ukraine


m_tobiasiewicz@...
 

Hi Sally!
How do you create a relationship/DNA chart and how do you put a chart in Files? Which gen program are you using?
Most of us are not familiar with that and your answer would be most helpful!
--
Maryellen Tobiasiewicz
family from: Bielsko-Biala powiat Poland
Gorlice powiat Poland
Lviv Oblast Ukraine


kdomeshek@...
 

There are three main types of DNA tests.  The replies so far have dealt mainly with autosomal, which is good for about 3-4 generations back.  After that, the signal-to-noise ratio in the test becomes problematic.  Also, Ashkenazim have a high incidence of endogamous DNA.  That contributes to frequent false positives when the autosomal test attempts to go back further than about 3 generations.  The response from "Sally B" above gave the correct math and referenced this limitation associated with endogamy.  Test agencies are trying to sell DNA kits, so their marketing literature is not likely to feature these autosomal test limitations.

Mitochondrial DNA is suitable for tracing the female line.  It goes back many generations.  I do not have experience with this test, but I expect it is capable of going back further than any Jewish genealogy you might have.  However, most Jewish genealogy follows the patriarchal names.  So, mitochondrial DNA research (the matriarchal line, mother-to-daughter, mother-to-daughter) has limited utility.  Not being sexist.  Just the way it is.  Blame our ancestors and their patriarchal proclivity.

A reply from "vivs" above mentioned Y-DNA.  This traces the patriarchal line, which is father-to-son, father-to-son, and so one.  As long as the direct patriarchal line is not interrupted with a daughter (which breaks the Y-DNA transfer to the male in the next generation), this DNA can prove a common male ancestor existed going back thousands of years.  It is easily capable of confirming a genetic relationship among males before the end of the patronymic period (circa 1750-1800).  Again, the limitation will be the genealogy, as precious few Jewish genealogical records reach into the patronymic period.  You may uncover conclusive proof of a close genetic relationship between two males using Y-DNA, but the genealogy may not be sufficient to tell you how or exactly when those two males had a common male ancestor.  You probably will never learn the name of that common male ancestor, if you have to go into patronymics.

You asked about Portugal vs Ashkenazim.  Portugal and Spain are usually Sephardic.  There are Y-DNA markers that are associated with Sephardic ancestry, but I do not have sufficient knowledge to confidently explain it.  I am participating in research that involves 150 Jews with oral history of being Ashkenazim and cohens, who have been proven by Y-DNA to descend from a cohanim line that started with an unidentified common male ancestor in biblical Israel, circa 500 BCE.  This research is being led by serious geneticists who make me a novice.  There is tantalizing evidence of a Sephardic connection in some of this DNA, despite the overwhelming preponderance of Ashkenazic ancestry among these 150 participants.  A plausible explanation is a Sephardic line of cohanim left Spain/Portugal in circa 1492 or thereafter, intermarried with Eastern European Jews who were probably also cohanim, and became comingled with Ashkenazic DNA.  If it can happen in this DNA study, it can happen in your situation, too.

Ken Domeshek.  (FTDNA project administrator, but not representing or compensated by Family Tree DNA)


Sally Bruckheimer
 

"Mitochondrial DNA is suitable for tracing the female line.  It goes back many generations.  I do not have experience with this test, but I expect it is capable of going back further than any Jewish genealogy you might have.  However, most Jewish genealogy follows the patriarchal names.  So, mitochondrial DNA research (the matriarchal line, mother-to-daughter, mother-to-daughter) has limited utility.  Not being sexist.  Just the way it is.  Blame our ancestors and their patriarchal proclivity."

Y-DNA is like mt-DNA, but the all male line. It also doesn't change for centuries, and almost all of the family names disappear in the 19th century sometime. It doesn't matter if it is the all female or all male line, so for genealogy both are useless. If you are a HOROWICZ or another surname that goes back further, they don't go back far enough.

The 'Cohen' gene marker is present in about 50% of men claiming Cohen status - and not in the other 50%. It is also present in some non-Cohen claimants. There is no proof that any gene is a REAL Cohen marker, much less than it came from Cohenim or Sephardim who may or may not have migrated to Eastern Europe. It is undoubtedly true that some Sephardim went to the Ottoman Empire, including Greece and the Balkans, and they may well have intermarried with Ashkenazi living there, but you can't prove anything with 'tantalizing evidence'.

Y-DNA and mt-DNA do not give an answer for what happened 500 or 600 years ago, and they can't tell you if you are Sephardic or anything else.

Sally Bruckheimer
Retired Molecular Biologist
Princeton, NJ