Thursday, 24 August 2017

What's So Great about Gedmatch?




1. It lets you see where you match people on each chromosome. This helps a LOT in that you can choose to only look at the matches that you share a specific space on a particular chromosome, meaning you narrow the trees you look at to only your Dad's side (Grandfather, Great-grandmother, if you know that much detail) and you don't get muddled up trying to find the common ancestor from two different sides of your family.

2. It lets people who tested at companies other than Ancestry upload their DNA, so you get to look at matches who tested elsewhere. Ancestry is still the biggest database, but I've found really close cousins at Family Tree DNA. Gedmatch may well one day out grow Ancestry in numbers of matches because of this ability to upload, free of charge.

3. It gives you a direct email address to contact people. There have been concerns about the efficiency of the Ancestry message system, particularly for people who don't have a paid subscription to Ancestry. Mind, I've only had 3 emails in the past year, so it's not like you'll be flooded with inquiries.

4. It is FREE. You can upload, see your matches, look at who matches both of you, look at exactly on your chromosomes where you match another person or how they match another. And many other things as well.

5. It's open, by which I mean you can look at anyone else's kit number to see who and how they match someone else. That means you can help someone else figure out something. It means you can work on someone else's matches without special permission (as if you're not going to have enough on your hands with your own matches). If you have someone else's kit number, you can access all the data they have put on line without special permission or paying any subscription fees. 

6. If you upload your family tree (called a Gedcom file), there is a facility that will compare your tree with another tree, searching for the common ancestor without your having to scan it name by name. That's pretty cool. It also lets you search all the other family trees uploaded for a specific ancestor and then check to see if you share DNA with any of the people who have that person in their tree.

7. Personally, I made a special family tree that I named 'Shelley's Lineage' to put onto Gedmatch. Gedmatch doesn't protect the privacy of living people who may be on your tree, like Ancestry does. I'm happy to put myself out there, but when it comes to attaching a tree to other people on Gedmatch whose DNA I administer, all their children and spouses, etc. who are on my Ancestry tree, that's a different story. I will be creating special trees with just their lineage to attach to their DNA. Where there are living parents, I can select to put 'Private Male' or 'Private Female'. 

8. You can buy more options for only USD $10 for a month's access. This can be done as a one-off, or you can set up monthly payments. I tend to do a one-off every 4-5 months when I feel I've exhausted the data I have. I haven't fully explored every option of what they call 'Tier 1', but the 'triangulation' feature is very useful. It creates a (very long) list of places on your chromosomes where two other people match with you. I don't understand all the ins and outs of genetic genealogy but apparently a single paired match isn't necessarily a 'true' match, but a triangulated one is. But don't rely on my explanation - there are any number of other bloggers who are expert genetic genealogists. I don't always understand what they are saying, but each time I read it a bit more sinks in.

9. In addition to Gedmatch, there is now Wiki-Tree, another FREE facility that shares the pedigrees of any number of people. They ask users to 'sign' an 'honor code' referring to good research habits. I've not signed up yet, will need to study up on what their criteria are for these good habits (I'm sure mine are ridiculously sloppy in comparison). Even if you aren't a member you can look at their data. One of the neatest things I found was that you can look at all the descendants of a given person (well, all the descendants that have been uploaded). I've used this to weigh up a hunch about how I'm related to some of my matches. 

Clearly I have loads more to learn about using genetic data for building my family tree. Let's just say I'm happily addicted to this whole process and look forward to understanding it better!

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