Most of my matches at ancestry don’t see why they should upload their data to GEDmatch. I send them the URL of my slide presentation and extol the delights of the fun ancestry composition (admix) tools but it is hard to explain why I like to see where my DNA matches someone else’s. Curiosity? It’s fun? I love making these spreadsheets? Possibly it is because I am very interested in how DNA inheritance works and love to see which grandparent gave me which piece of DNA (n.b. it takes a lot of work to get to that point).
When I know the common ancestor for a specific segment sometimes a new match fits in immediately to a family line. The best example of that is finding my previously unknown 3rd cousin Katy. When I saw where she overlapped I emailed her that it looked like she was related on my WOLD line to which she responded that her grandmother was a Wold. She has since sent me many wonderful family pictures that I had not seen before.
Today I got an email from someone who had tested at ancestry and uploaded to GEDmatch. She wanted to know how to use my tools with her GEDmatch data. However my tools require a CSV file of overlapping segment data which cannot be downloaded in one fell swoop from GEDmatch, unlike at 23andme or Family Tree DNA.
Personally I built my many CSV files (one per person tested) slowly, as I compared each individual’s DNA results, contacted that match, and then cut and pasted the overlap information into my spreadsheets. Jim Bartlett did a great guest blog here on the process of building these DNA spreadsheets.
But I can understand the desire to see a quick picture of your matching DNA. GEDmatch does have a chromosome browser where you can see the overlaps, although the presentation is somewhat different from other sites. A little known secret is that you can massage that function’s table output into a spreadsheet (see end of this post for the technique).
My friend Angie Bush is a most creative genetic genealogist whose daughter Brynne is apparently following in her footsteps. They do a lovely presentation on autosomal DNA together which includes this slide showing four generations of DNA inheritance, made with my ancestor chromosome mapper.
Four generations of DNA to Brynne (click to see a larger version)
By Jim Bartlett
Impressed by Jim Bartlett’s prose on various message boards and mailing lists, I asked him to do a guest blog post on using spreadsheets with autosomal DNA results, here it is – Kitty
Using autosomal DNA testing can be a challenge – but it doesn’t have to be. It can be intimidating – but by taking it a step at a time, you can break it down into bite-sized pieces that are much easier. When you decide to use autosomal DNA (atDNA), and to get the most out of it, I recommend three broad areas of focus right from the start:
- Learn all you can about DNA testing for genealogy and particularly about autosomal DNA (atDNA). The ISOGG wiki is a good place to find good articles, tools, blogs (to keep you up to date), etc. Join email lists and read and ask questions. This is definitely a “continuing education” hobby. We are on a frontier with genetic genealogy – and we are pushing the boundaries every day!
- Create as robust a Tree as you can – stretch as much as you can to 12 generations, or more. This is the net you need to catch cousins and find your Common Ancestors. This is very important – if you don’t have the ancestors in your Tree, you cannot expect to find a Common Ancestor with a Match.
- Set up a process for your autosomal DNA project. To determine Common Ancestors you have to share ancestry info with your DNA Matches – you’ll be sending (and receiving) a lot of emails and messages. You’ll want to keep track of what you do; to find info on your Matches; to remember the Common Ancestors you determine; new names, new emails, new links to Trees, etc., etc. You may want to use a spiral notebook as a Diary or Journal of your notes. Some people keep a notecard for each Match, or a folder. I now have over 3,000 matches at FTDNA and 23andMe, so I need something that can handle that many (and more) Matches. Many of us use a spreadsheet – read more to see how to set up one.
So many people were trying to use my DNA chromosome mapper tool to look at a picture of their DNA relatives’ matching segments that I realized that another tool was needed to meet that demand. The first version of the new DNA segment mapping tool is ready. More information is at http://blog.kittycooper.com/tools/segment-mapper/
Sample Output from the DNA Segment Mapper
The DNA Segment mapper can show the matching DNA from up to 40 people in a chromosome style chart. Here is what my Dad’s top 40 matches look like (names are removed). The first two are first and third cousins once removed.
There is a page under tools above with more complete description and documentation.
The DNA segment chromosome mapping tool is now released for all to try. This is the current URL:
and the documentation is here:
Thanks to all the testers, I think the bugs have been found and fixed. The next release will have some enhancements so make your suggestions here. So far I expect to add the following features:
- ignore the side column so alternately chose a side and color
- better error reporting and more bullet proof
- add a third option and thus line on the chromosomes for unknown or both
- add a note column that is part of what appears on mouse over with the MRCA
- allow selection of colors
- make a version designed to show overlaps on unknown relatives