I’d like to start off my blog with a big Thank You! I’m very grateful:

  • to my siblings, who agreed to take DNA tests. (And one day I’ll blog about why testing siblings can be a good idea.)
  • to close relatives of my mom and my dad who also agreed to test. It’s so helpful to look at a stranger’s matching DNA and compare it to yours. If it matches you too, then I know which of my parents’ or grandparents’ ancestors will hold the key to our common roots.
  • to more distant relatives that I’ve encouraged to test. Because of you, I’ve developed new leads on what village in Ireland one great-great grandfather came from. Because of you, I’ve found distant cousins of a different race, and we’re exploring which slave-owning ancestor *might* belong in both our family trees. It takes time, but in coming months I’ll probably blog about some of our progress in these or other mysteries and brick walls.
  • to my relatives whom I never knew until the DNA company told us we match. Howdy, cousins! And I want to thank you for replying to my messages or emails, for sharing some of your family history, for helping me in my quest and letting me help you.
  • And finally, to everyone who has agreed to copy their raw DNA data to the free tool at and to the wonderful volunteers who provide that service for all of us ‘citizen scientists’ who are exploring how DNA can help us discover and understand more of our heritage.

Thank you all!

Speaking of GEDmatch… If you haven’t copied your DNA data there yet, here is some information that may help you do so. Many folks have created web pages or blog posts about GEDmatch. I’ll point you to some of my favorites, below.

In a nutshell, here’s what someone new to genetic genealogy needs to know.

Every testing company compares your DNA to other people who have tested at that same company. If you’ve tested at AncestryDNA and you have a second cousin who tested at 23andMe and a third cousin who tested at FamilyTreeDNA, you will not appear on each other’s list of people you match. But if each of you copied your raw DNA data to, you would show up as matches there. So if you don’t want to limit your cousin discoveries to people who tested at just one company, and would like to know who you’re related to regardless of where they tested, GEDmatch is a free tool to help you out. (Provided those other cousins also copy their data there…)

The basic tools at GEDmatch are free. And it’s not too complicated. First, you download your “raw” DNA data (not your matches) from wherever you did an autosomal test (i.e. not a Y-DNA or mtDNA test; the ‘regular’ kind). It will end up as a zip file on your desktop computer hard drive; don’t unzip it. (If your MAC unzips by default, you can change that. You do need to do this on a desktop computer, not a phone or tablet or iPad.)

Then register at GEDmatch (with email address and create a password) and upload that data. You can choose to set up an alias if you don’t want your real name shown to your matches. Users will see your email address, and you’ll see theirs.

Here are some websites that have very helpful step-by-step instructions on how to get started. All links were accessed this month.

Tested at FamilyTreeDNA or Ancestry DNA?

Diahan Southard, Your DNA Guide, “GEDmatch,”

Tested at 23andMe?

Interpret Your Genome, “Ways to Get More from your 23andMe results,” > GEDmatch – What It Is, how to use it,

It may take a day or two before you can access all the functions. What can you do at GEDmatch?

Right away, you should be able to:

  • see if it can predict your eye color
  • confirm whether or not your parents were related to each other
  • do a one-to-one comparison with your kit number and someone else. Did someone—like me?—ask you to copy your data there? You can compare your DNA to that person. My kit is A876964 if you want to compare it to mine. Leave the default settings (e.g. 7cM, 700 SNPs) as they are. The query will tell you if you and the other person share a matching chromosome segment and where.
  • if you have a sibling who tested, you can tell in the one-to-one whether you match on just one copy of that chromosome (the one from your mom or the one from your dad) or if you match on both copies of a given chromosome for a certain segment. (I’ll talk more about that in a blog post on testing siblings. One day.)
  • play with the ethnicity predictors. (They are a lot more cryptic than the ones at your testing company!)
  • you can upload a gedcom (i.e. your family tree) now or at any time you like, so your matches can see it, if you want.

After a day or two, you can:

  • do a one-to-many query: enter your kit ID and it will return everyone else in the GEDmatch database that shares a matching chromosome segment with you, sorted by how close the relationship. There is a lot more you can do from there.
  • do a people-who-match-one-or-both-of-two-kits query. Enter your own kit and a known relative’s kit ID if you’ve got one. This query will tell you who matches both of you—this is a great feature to narrow down which of your family tree branches a new cousin might belong to.
  • begin to explore triangulation. If you have 3 or more people who each match each other on the same identical or overlapping segment of a chromosome when you do a 1-1 comparison (i.e. A matches B, A matches C, B matches C, all on the same segment), then that DNA probably came from the same person. You have the email addresses right there to contact your matches and see if you can share your trees and find that common ancestor.

There’s much more to GEDmatch, but I think this is a good beginning. If you want more ideas, check out either of these posts:

Dan Stone, Adventures in Genealogy Research [blog], “Chromosome Mapping And GEDmatch: An Overview Of What They Are And What The Benefits Are,” 29 July 2014, (

Louise Coakley, Genie [blog], 29 Jan 2016, “Tips for Using GEDmatch,” (

Of course, GEDmatch has an FAQ on their website too. There are more features I haven’t mentioned, but one step at a time. Just know that it’s a tremendously valuable tool for using DNA to find distant cousins who may have new leads to break through your brick walls—and it’s free! What are you waiting for?


(c) Ann Raymont 2015

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