Tuesday, September 19, 2017

Endogamy, A Closer Look (Part 3)

This is the third post in a series examining 355 pairs of my own relatives who have tested, looking at how much DNA each shares in total as well as the size of the largest segment.  (The previous posts in the series can be seen here and here.)

Everyone here has 100% Ashkenazic Jewish ancestry unless noted otherwise in the "Comments" column.  All numbers are as given by GedMatch with the exception of comparisons with Benjamin, JudithB, Shannon & Layla who are only on FamilyTreeDNA.

For each relationship section, I give the expected amount of shared centimorgans according to ISOGG.  I've also added in low/high ranges (at the 99th percentile) and average amounts shared according to the Shared Centimorgan Project (SCP) based on feedback to the first post.  In addition to looking at overall shared DNA for each pair, I also note the size of the longest shared segment.  Each relationship section gives the average amount of shared DNA and largest segment looking at those who have 100% Ashkenazic Jewish ancestry.


This post discusses people who have tested and who are known third cousins and more distant.  It also discusses some of those who are known to be related to one another in more than one way.  For those double cousins, I added the expected amounts of shared DNA for the two relationships for the ISOGG values.  I also added together the two low values, high values and average amounts given for the two relationships by the SCP.
Endogamy gives you lots of matches.  What does a true match look like?

Sunday, September 17, 2017

High Holiday Tickets

With Rosh Hashanah coming up this week, it seems an appropriate time to post these documents.  My Tolchin grandparents and Joshowitz great grandparents were long-time members of Gemulas/Gemilas Chesed Congregation (which used several different spellings for its name) in McKeesport, Pennsylvania.
High Holiday Ticket for my Great Grandmother, Esther Joshowitz, 1959

Wednesday, September 13, 2017

Endogamy, A Closer Look (Part 2)

This is the second post in a series examining 355 pairs of my own relatives who have tested, looking at how much DNA each shares in total as well as the size of the largest segment.  (First post in the series can be seen here.)

Everyone here has 100% Ashkenazic Jewish ancestry unless noted otherwise in the "Comments" column.  All numbers are as given by GedMatch with the exception of comparisons with Benjamin, JudithB, Shannon & Layla who are only on FamilyTreeDNA.

For each relationship section, I give the expected amount of shared centimorgans according to ISOGG.  I've also added in low/high ranges (at the 99th percentile) and average amounts shared according to the Shared Centimorgan Project (SCP) based on feedback to the first post.  In addition to looking at overall shared DNA for each pair, I also note the size of the longest shared segment.  Each relationship section gives the average amount of shared DNA and largest segment looking at those who have 100% Ashkenazic Jewish ancestry.
I have a LOT of potential matches.  What do real matches look like?

Thursday, September 7, 2017

Endogamy, A Closer Look (Part 1)

[Edited based on comments to include numbers from the Shared Centimorgan Project.]

I've blogged before about how endogamy impacts my matches with known relatives--to hopefully allow for others to extrapolate how it will impact their own genetic genealogy analysis.  But I realized that I have a lot more data--many of my relatives who have tested are have known relationships to one another.  I currently have 355 pairs of relatives (all with at least some Ashkenazic Jewish ancestry) who are related to one another, and I can examine how much DNA each pair shares.

For each relationship section, I give the expected amount of shared centimorgans according to ISOGG.  I've also added in low/high ranges (at the 99th percentile) and average amounts shared according to the Shared Centimorgan Project (SCP).  In addition to looking at overall shared DNA for each pair, I also note the size of the longest shared segment.  Each relationship section gives the average amount of shared DNA and largest segment looking at those who have 100% Ashkenazic Jewish ancestry.

Everyone here has 100% Ashkenazic Jewish ancestry unless noted otherwise in the "Comments" column.  All numbers are as given by GedMatch with the exception of comparisons with Benjamin, JudithB, Shannon & Layla who are only on FamilyTreeDNA.
Marriage Within the Vizel Family (as viewed on https://learnforeverlearn.com/ancestors/)

Wednesday, September 6, 2017

FTDNA & Hurricane Harvey

I blog about DNA a fair bit, and my testing company of choice (largely due to the chromosome browser and the ability to do Y and mtDNA tests) is FamilyTreeDNA, which is based out of Houston.

FTDNA has sent out the following announcement:

Sunday, September 3, 2017

When There Are No Records For Your Family's Town On JewishGen

On various Facebook groups, people regularly post saying that they've searched for their family on JewishGen but that there was nothing for that family's town.  Well, there's something those people can do about that!  JewishGen is overwhelmingly run by volunteers as are affiliated independent organizations like JRI-Poland--so why not be one?  You can help yourself and others.  Here's the type of information you may get for yourself (and others researching the same towns) and how you can do this.
Death record for my great-great-great-great grandmother, Tzipra Brandman--found via a JewishGen project I run

Monday, August 21, 2017

A Relationship Outlier

Blaine Bettinger runs the Shared Centimorgan Project in which he's collected thousands of data points for amount of DNA shared between people with known relationships.  He can give a range of DNA which has been observed to be shared for people with specific known relationships.  If you have a new DNA match, you can see how much DNA you share with that person and use Blaine's chart to identify potential relationships that are possible with that person.
Shared cM Project.  From http://thegeneticgenealogist.com/wp-content/uploads/2016/06/Shared-cM-Project-Version-2-UPDATED-1.pdf.  Used with permission.