Can Y DNA Solve an Unknown Parentage Case?

Sometimes testing the Y chromosome can help when you are looking for a missing father, grandfather, or further back as long as you have a tester descended on the male only line. Remember the Y is passed father to son, so any changes are rare and are caused by mutations not recombination. Typically a man would start with a Y 37 STR marker test at Family Tree DNA to see if this avenue is worth pursuing. A STR test gets the most recent changes rather than the haplogroup, thus can suggest a surname. Click here for my article explaining Y testing.

Slide from my 2017 talk on DNA testing for genealogists featuring my maternal grandad

The Y results will not help if no other men from that Y lineage have tested unless you have a theory. In that case you need to test someone else descended on the male only line from the presumed ancestor.

Y testing can be very useful when the unknown parentage occured many generations ago, such that autosomal testing may not be able to solve it.

If your ancestors have been in the USA for some time then a Y 37 STR marker test may find a probable last name. In that case there may be a surname project with other Y testers at Family Tree DNA. I recommend contacting the admins of that project as they can often be a great help in your quest. However if you are from a population group which has only had inherited surnames for two hundred years or less, quite likely you will have no luck.
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Family History Fanatics Winter DNA Conference!

I will be doing a talk on GEDmatch Basics for the Family History Fanatics (FHF) Winter DNA Conference. They also have a youtube channel (click here). Here is the Press release from FHF:

KICK OFF THE YEAR RIGHT

Saturday, 30 January 2021 beginning at 9:45 AM Eastern Time.
If you can’t attend the event during the live sessions, you’ll have access to the replay for 30 days.

TOPICS & PRESENTERS

  • DNA & Law Enforcement – Marian Woods
  • GEDmatch Basics – Kitty Cooper
  • Tracing Ancestral Lines in the 1700s Using DNA – Tim Janzen
  • A Guide To Chromosome Browsers & DNA Segment Data  – Michelle Leonard

 AFTER THE SESSIONS

The four panelists will return for a “test your knowledge’ competition and then more of your unscripted rapid-fire questions. 

Early bird pricing is $19.99 until January 22nd. After that, pricing will increase to $24.99. 

When you register, you’ll be entered to win genetic genealogy-related door prizes. 

To learn more and register visit, www.familyhistoryfanatics.com/winterdna

Family History Fanatics is a genealogy education company that is focused on putting the fun into online learning. See the difference the FHF Group puts together for you.

Goodbye Yahoo Groups

Yesterday, December 15, was the last day of Yahoo groups. Those mailing lists were places where we could ask questions and be answered by others who had already solved similar problems. We also got news about things of interest to the particular group we were following.

Yes there was plenty of notice that this would happen, but still, I was not really ready, were you? Most of the groups I belonged to sent me emails telling me where they had moved to, often long ago. The top two providers chosen were Google Groups and Group.IO – you can always search each of them for your old group name and then sign up again when you find it.

However, much of that asking for help activity has long since moved to FaceBook. Personally I prefer the old style mailing lists because it is easier to find what I am looking for in their archives. Maybe I am just too 20th century still.

For genetic genealogy there is a list of Facebook groups and mailing lists at the ISOGG wiki here:
https://isogg.org/wiki/Genetic_genealogy_mailing_lists_and_Facebook_groups

Here is a list of the mailing lists I follow at their new homes:
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ALERT – Bug in the GEDmatch “Are Your Parents Related Tool”

UPDATE: 13-Dec-2020: FIXED! The code had not changed but the environment had, so an initialization was different. Thus my analysis that it was always the first few chromosomes helped the programmer solve the issue.

 

The “Are Your Parents Related Tool” (AYPR) has been an enormous aid to those adoptees who discover that they were a result of an in-family relationship. Thus it is very distressing to have gotten a report from a reader that the tool is suddenly showing less cM that are ROH than it used to.

My investigation has shown that the first few chromosomes have segments that are not marked as ROH when they should be and were in previous versions. The programmer who can fix this told me that this bug goes back perhaps as far as this past summer He does have a working copy from July, but is in the middle of a major new project. Thus he may not be able to attend to this until later this coming week,

In the meantime, here is an example of how this looks so you can try to make your own estimate. The results for a child of first cousins was shown in my blog post about this tool (click here for that post).

ROH for child of first cousins,  buggy version on left, previous correct version on right (click for larger version)

To the left is how that looks now, while on the right is how it looked last year. Notice that the first three chromosomes on the left have not been included in the ROH listing. Also, the previous total was 215.3 which, when multiplied by 4, fit the first cousin scenario, now confirmed. The total without those first few chromosomes today is 126.8.

The cases from closer relations are even further off. A child of siblings had 744cM ROH last year but now gets only 465.6. A child from a father daughter pairing was was 750.4 and is now 547.9. In both cases the problem was the first four or five chromosomes were not having their ROH segments counted any more.

I will post an update on this blog post once the issue is fixed.

Monday Presentation: MyHeritage’s Theory of Family Relativity

MyHeritage has been producing a wonderful series of live presentations via their FaceBook page. At 11 a.m. Monday (tomorrow) California time I will be giving a talk on how to use the Theory of Family Relativity. If you come to this free lecture you might win a free DNA kit plus you can ask me DNA questions live.

Otherwise you can view it later by clicking on the videos tab on their page. I am amazed that my last video for them about finding cousins using DNA at MyHeritage had over 20K views!

One of the slides in my talk, slides are at https://slides.com/kittycooper/myheritagetofr

In other news from MyHeritage, this year they finally have the ability to give a gift membership in time for the holidays and they have already started their Black Friday sale.

UPDATE 23-Nov-2020: The video of my talk is now available on the MyHeritage FaceBook page here:https://www.facebook.com/6572227821/videos/150034700143856 and the image above is linked to the slides. Plus here is the Black Friday sales link: this limited-time offer ends November 27, and the price is $39, plus free shipping on 2+ kits if ordering from this link.