Search Results for: gedmatch

A Really Basic Approach to Using GEDmatch

Feb18

GEDmatch.com is about to get a face lift. Many have complained that it is not intuitive and does not offer enough help for a newcomer. The new site hopes to correct some of that; I am helping with the beta test now; it sure is prettier!

Why use GEDmatch and what is it? Well it’s a free 3rd party site of tools where you can upload your DNA test results and compare them with those from people who have tested at other companies. Plus there are many analysis tools, some available nowhere else. These include GEDCOM (family tree) comparisons, including yours to your DNA matches.

Recently I gave a talk for the Family History Fanatics at their Winter of DNA conference where I demonstrated how to use GEDmatch without worrying about segments. An approach that gets a lot out of the site without having to be a geek like me. The slides are here: https://slides.com/kittycooper/gedmatch-basics-2021

Here is a step by step of that very basic approach as outlined in the syllabus for my FHF presentation

1. Create a User ID and Upload a DNA raw data file, aka a “kit”

Click the image above to go to the video from Andrew Lee, of FHF, which shows you how to create a user id and upload your DNA raw data to GEDmatch.

Or read this blog post of mine which also has links to my other GEDmatch posts
https://blog.kittycooper.com/2019/02/genesis-basics-gedmatch-reinvented-part-1/

2. Once Logged in, your Dashboard Page is not Intuitive

The tools are in the right hand column and the resources you have uploaded are listed on the left. You can upload more than one DNA kit and multiple GEDCOMs. There is a help section on the top right.

This post from Jim Bartlett is a useful explanation of the home page, as is my basics post listed above.
https://segmentology.org/2018/05/01/first-time-at-gedmatch/

And here is what my beta test Dashboard looks like, an improvement? I think so.


Continue reading →

ALERT – Bug in the GEDmatch “Are Your Parents Related Tool”

Dec12

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.

Tool to find common ancestors at GEDmatch

Jul4

Whenever I get a new good-sized DNA match, I try and figure out how we are related. Ancestry and MyHeritage both have clever tools that search your tree and the trees of other users to come up with the likely relationship. Of course both you and your match have to have a family tree connected to your DNA on those sites for that to work.

My father’s DNA matches with matching ancestors, first run

GEDmatch has just released a tool for its Tier 1 (paid) members that will search for the common ancestor you have with your DNA matches on that site. This capability requires both you and your match to have uploaded a GEDCOM to GEDmatch and associated it with your kit. I just updated my 2015 blog post about using GEDCOMs at GEDmatch which explains much about them, so click here to read it. By the way, a GEDCOM is a text file that is formatted especially for genealogy programs; it lets you move the facts in your tree from one genealogy web site or program to another.

The new tool found nothing on my mother’s side. She was German and half Jewish. There are almost no Germans at GEDmatch and my one known half 2nd cousin on there has no tree uploaded. As to the Jewish side, very few have their trees far enough back to meet mine. I need to get a few of my known 3rd cousins to upload GEDCOMs.

The above listing, partially repeated below,  shows all the common ancestors my first run of this tool found for my Norwegian-American father using the default settings on the form. I have cut off the first 3 columns on the left which have the kit number, match name, and email address for privacy; also that makes the image readable on this page!


Let’s look at the rest of the columns for my Dad’s top match. Clicking the tree icon would take you to the user profile information. The cM shared are listed next; 40.3 is match that can be anything from a 4th to an 8th or even more distant cousin. Then the name of the possible shared ancestor, first in my GEDCOM and then in my match’s GEDCOM; either one can be clicked on to go to that person’s tree entry. The 8G is how many steps down from that ancestor my Dad is. If you click that, you see a descendant list from that ancestor in your tree. Notice that his match is also 8 steps down, so in the same generation. Subtract one to get the cousin level so this is a 7th cousin.
Continue reading →

The Genetic Detective, Gedmatch, and me

Jun27

I am loving watching the Genetic Detective on ABC every Tuesday night and I really hope you are too. It is a new true crime series starring CeCe Moore which demonstrates the use of genetic genealogy to catch rapists and murderers. As someone who uses similar techniques to solve unknown parentage cases, it gives me great joy to see this show and share it with family. I even announced its debut to my blog’s mailing list.

If you do not get ABC in your television package, you can view it on HULU or wait a week and click here to see it on the ABC website.

It was a lecture by CeCe back in 2012 that got me started on this DNA pathway. After I solved a few of my own family mysteries, I started writing this blog and helping others with their quests. Now I even teach at the i4GG conferences she organizes every year (videos available).

What I hope my friends and family get from this show is a better understanding of how DNA sleuthing works and why they should upload their DNA results and a family tree to GEDmatch and Family Tree DNA to help solve crimes like these. What is most enjoyable for me, is that each week so far there has been a slightly different genealogy challenge for solving the case.

Photo of my TV showing my Compact Segment Mapper at Gedmatch from episode 5

Continue reading →

Important Changes at GEDmatch

Dec17

If you have not logged into GEDmatch recently, please do so and either accept the new terms and conditions or don’t. Unless you are clearly USA based*, your kits will not be visible to your relatives any more unless you accept. I have linked to numerous other blogs at the end of this article to help you make your choice. I recommend reading either the one from Roberta Estes or EU users, the one from Debbie Kennett. Both look carefully at the new terms and conditions which are not very different from before.

Frankly, I was surprised by the panic expressed last week by some in the genetic genealogy world on FaceBook due to the sale of our beloved GEDmatch DNA tools site to a forensic science company. Personally, I hate knee jerk reactions so I did some research into this company, Verogen, as well as communicated extensively with Curtis Rodgers, one of the GEDmatch founders, and Kim Mohr, a spokesperson for Verogen.

To remind you all, GEDmatch is the best place to compare DNA tests done at different companies to each other or just to see the actual chromosome locations shared by two Ancestry testers. While both Family Tree DNA (ftDNA) and MyHeritage accept uploads of tests from other companies so you can compare on those sites, neither has the extensive tools of GEDmatch. FtDNA compares down to very small segments which can be useful in a family project but leads to inaccurate relationship estimates. MyHeritage does not show the X chromosome and neither company shows the fully identical segments (FIRs) that full siblings will have, which can be so helpful (click here).

The DNA Applications menu at GEDmatch

GEDmatch has many useful additional tools, such as “People who match both or 1 of 2 kits ,” an “Are your parents related?” test, the ability to see who matches you on a specific segment, being able to check for full siblings rather than half, and automated triangulation, to name a few of my favorites (click those words to go to that post when I did one or click here for my more general GEDmatch articles). Plus it has GEDCOM comparison utilities. Compare yours to all the ones in the database or to just one other.

GEDmatch became a center of controversy when it was discovered that genetic genealogist Barbara Rae-Venter, working with law enforcement (LE). had solved the Golden State Killer case (click here) using that site. Since that time, there have been more controversies around law enforcement’s use of the site and many overblown scare articles in the press. Personally if my DNA outs a distant cousin who is a murderer or rapist, that’s fine with me. Genetic genealogy techniques are used as a tip; no one is arrested without getting their DNA from discarded materials and seeing if it is a match to the crime scene. I know some people are afraid of the possibility of false arrests, but that just does not happen with these modern techniques. You can, as before, choose to opt out of allowing LE to see your results on GEDmatch when looking for cousin matches to the dna of the perp or the unidentified victim.

In recent months, there have been more problems, news stories and controversies, including a Florida search warrant being granted. One has to feel for the two retired hobbyists who founded GEDmatch to help in their research and ultimately help us all, keeping most of the features free. Clearly getting the site owned and managed by a more professional group would be of great advantage to the users. Curtis spent several months looking for the right partner that would respect the original misson of GEDmatch and yet deal appropriately with LE, the EU, and security issues. He and the programmers, the two Johns, will continue to work on the site as consultants.

So who or what is Verogen? Two years ago this company was spun off from Illumina (the maker of the chips and machines that all the consumer oriented DNA testing companies use to sequence your DNA). It has 50 plus employees and plans to continue growing. Their office is in a small office park near UCSD here in San Diego. Continue reading →