Recently I gave an updated talk about GEDmatch.com for my local DNA special interest group, DIG, here in San Diego. GEDmatch.com is a DNA geek’s playground, but many less computer inclined folk find it difficult at first.
It is the only place for those who have tested at Ancestry DNA to compare their results to a possible relative, chromosome by chromosome. It also has many tools that are unique such as ancestry composition calculators with more recent breakdowns and more categories than the main companies. I covered those in detail in my original talk about GEDmatch tools. Those slides are at http://slides.com/kittycooper/gedmatch#/5
The new talk – http://slides.com/kittycooper/gedmatch-10#/ – covered uploading your data, how to manage your kits and mark a kit for research, and much detail on the one-to-many function as well as all my other favorite tools (starred in the image to the left).
There is a new 23andme upload which is nice and fast as it uses the API so you actually log into your account there rather than uploading a file.
It makes sense to upload all your kits when you have tested at more than one company but please mark all but one kit as research only, so DNA relatives are not confused by seeing so many versions of the same person.
Today I sent the following email to a newly found DNA cousin match at ancestry whose great-grandmother lived right next door to my family in Kristiansand, Norway in the late 1800s. She moved to the U.S.A just a year after they did (1884 and 1885) and lived a block away from where my grandad eventually lived on Ovington Ave in Brooklyn, N.Y.
OK now I REALLY want to see where our DNA matches, because I have a large database (spreadsheets) of where my Dad, my brother and I match various known Norwegian relatives so it is likely that I can figure out from the matching DNA segment(s) where we are related and if it is really the 7th cousin match shown at Ancestry.com on the Eigeland line.
Pretty please either upload to GEDmatch or Family Tree DNA or both.
First you will need to get the raw data from Ancestry.com – here is how:
There is a new feature at GEDmatch.com – you can look at the GEDCOM of a DNA match easily again.
Take the kit number of interest and plug it into the user lookup form. On the next page, with the information about that kit, it will either say NO GEDCOM UPLOADED or there will be a GEDCOM id number. That id number is now clickable and will take you to the person associated with this kit number in the GEDCOM.
If you have not uploaded a GEDCOM to GEDmatch.com then I highly recommend that you do so. It is helpful to be able to compare your GEDCOM to that of a DNA match. I prefer just 10-12 generations of my ancestors (privatized) as my full family file is way too large. My theory being that is enough generations for DNA matching and I only want ancestors for my DNA matches to look through.
I have used red arrows on the above sample excerpt from a GEDmatch home page to show where to upload your GEDCOM file and where to click to do a user lookup.
Here is a the step by step example:
There are four exciting new utilities at GEDmatch.com which I plan to cover in depth over the next several days. These are only available to for people who have donated at least $10 (every additional $10 gets you these for another month). A good way for GEDmatch to pay for their extra server costs. The rest of the site will remain free. The utilities are:
- A Matching Segment Search – Get a list of all your segment matches suitable for cutting and pasting into a spreadsheet
- A Relationship Tree projection – calculates probable relationship paths based on Autosomal and X-DNA Genetic Distances. It is experimental, try it and give them feedback
- Lazarus – Construct a kit to represent a close ancestor, wow!
- Triangulation – takes your top 300 matches and finds which ones match each other with details. The format can be copied to a spreadsheet
I think the switch from Ancestry.com DNA test results, where your tree gets searched for you, making using DNA with genealogy easy – to GEDmatch where you have to figure out how to use the data yourself, is quite difficult. So this post is an attempt to help my cousins who have tested at ancestry and uploaded to GEDmatch. It might also help others new to GEDmatch who want to look at where they match a [possible] cousin by walking through that process.
Sample from the GEDmatch one-to-one comparison
- First make sure that you understand current DNA basics (click here for my page on that). Genetics have advanced greatly since my high school biology class and perhaps since yours too.
- Next realize that the raw data from your test is only a small part of your genome, a sampling. It is the SNPs that are currently considered the most interesting. They represent the most likely spots where we are different from each other. If a contiguous sequence of those SNPs is the same in two people for about 10 centimorgans (cMs) or more then they are expected to share a common ancestor. With a match of 7-10 cMs it is likely but not a sure thing. There is a good article in the ISOGG wiki on the likelihood of a match at different segment sizes.
- In order to see where your DNA matches someone else’s, you need your kit number and his kit number. Then you can use the one-to-one comparison to see on which chromosome(s) you match each other. Your kit number shows on your GEDmatch homepage. You can find the kit numbers of other possible relatives in the one-to-many display or perhaps your new cousin has sent you his kit number.
- I recommend that you keep a spreadsheet with the information on your matches, sorted by chromosome and start point, so you can see who else a new match might match. I have a number of posts on this blog about using spreadsheets and a template in my downloads area. Many people like to use the genomemate tool to organize their data.
The image above is from a recent new match to my Dad uploaded from ancestry.com. The blue rectangle shows where there is a DNA match. The numbers in the box are what I cut and paste into my master spreadsheet for Dad.