I will be doing a talk on GEDmatch Basics for the Family History Fanatics (FHF) Winter DNA Conference. UPDATE: 25 Jan 2021: I have received screen shots of the new look coming soon to GEDmatch; these will be featured in my presentation.
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.
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:
Here is a list of the mailing lists I follow at their new homes:
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.
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!
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.
Much of the work to build tools and write articles to help testers with their DNA results has been done by citizen scientists, bloggers, computer programmers, and scientists from other fields like Andrew Millard (behind the WATO math). In an exciting development, Amy Williams, a computational biologist at Cornell University, has built a few DNA tools, with more to come, and started a blog at https://hapi-dna.org/blog/
Her blog article titled “How often do two relatives share DNA” is particularly interesting. It includes the beautiful chart shown below which is created from simulations. Click it to go to the actual page where you can mouse over the columns to get the detailed numeric breakdowns.
The other article on her blog has a detailed explanation of what a centiMorgan is, the measurement used for DNA segment sizes (click here). I usually recommend not worrying about the exact definition since it is a measure of the frequency of recombination rather than a physical length. It is important just to know that there is not a one-to-one relationship between the cM and the sizes shown in the chromosome browsers. On the those charts, the same cM amount looks smaller at the ends of chromosomes than it does in the middle because recombination is more active on the ends.
The final statement of that article is: “In an upcoming post, we’ll talk more about cM lengths of DNA and how recombination leads more distant relatives to share fewer segments that are also on average smaller than those that close relatives share.” Something to look forward to!
Now to take a look at the tools that are available there so far.
Of particular interest to adoptees is the maternal versus paternal predictor for half siblings or grandparents. I tried it out on a number of half sibling pairs who I have helped in the past.
Here is the prediction created for a brother and sister who share the same father but have different mothers, using the comparison of their segment data from 23andme:
However I discovered number of minor usage issues when trying to use data from the different DNA testing sites.