Why use GEDmatch and what's new as of 2020
All my slides are always online at
No Basics today, just the why and the new
GEDmatch has vastly improved their documentation
We can talk about the elephant in the room at the end of this talk
The sale of GEDmatch to VEROGEN
So far nothing seems to have changed due to that sale
GEDmatch is still the best place to compare your kit to DNA tests from other companies
example of the Beta one to many comparison
Why is GEDmatch is still the best place to compare your kit to DNA tests from ancestry or when tested at 2 different companies?
- MyHeritage does not show the X
- Family Tree DNA does not show comparisons of third parties to each other nor triangulations
- Neither shows fully identical regions (FIRs)
- and there are way more segment level tools at GEDmatch
If you and a DNA relative are both tested at Ancestry, you can upload to GEDmatch to see the actual segment data
Viewed as an image, the HIRs show as blue bars and the FIRs show as green bars
http://blog.kittycooper.com/2016/04/full-versus-half-sibling-dna-matches/
Or view just the numeric data
The X chromosome is a separate comparison
Note that here we are getting both numbers and image
The Basic One to Many now has all the migrated kit overlaps
The column headings are explained at that same basics post
https://blog.kittycooper.com/2019/02/genesis-basics-gedmatch-reinvented-part-1/
It also shows the overlap which is how many SNPs are available for the comparison
The Basic One to Many is the only One to Many report which shows the company tested at
So what does Combined mean?
You can create a kit which combines all your test results from different companies (paid option)
After combining kits, I mark the others as research - R
Note that the legend above your DNA resources explains all the new icons used
Notice how many more SNPs the combined kits have
Here are some numbers for different kit sources determined by using the DNA File Diagnostic Utility on a number of kits
What's new on the one to one?
FIRs and prevent hard breaks!
plus the annoying Captcha. You have to clear cookies occasionally when it asks for the captcha agan but does not show it
Why check the prevent hard breaks?
Same comparison with prevent hard breaks checked (N.B. 2 sisters with the same Dad will share a full X)
X comparison of 2 full sisters shows a black spot in the middle indicating no match, this happens when distance between SNP's exceeds 500,000 base positions
Why show only the FIRs? doubly related people like full siblings, 3/4 sibs, double first cousins will all have these
Normal one-to-one image chr 1-8
Just FIRs one-to-one image chr 1-8
At the bottom of the image comparison are the numbers
For full siblings HIRs + FIRs = about 3600 (so a real 50% like a parent)
https://blog.kittycooper.com/2019/10/why-dont-we-share-more-dna-with-a-sibling/
Some examples
3/4 siblings HIRs + FIRs = theoretically about 2500
example known 3/4 siblings: 2267.7 + 533.8 = 2801.5
Tier 1 members have a more accurate One to One for checking on the validity of small segments
A normal one to one
My and my new 3rd cousin, shared Jewish ancestral couple
The Q matching One to One
Q pile ups: My aunt and my new 3rd cousin
SNP density: My other aunt and my new 3rd cousin
Recently a Norwegian DNA match to Dad with a deep family tree found that he is my 12th cousin twice removed
His single segment match to my Dad and my brother is in a pile up area with about 100 or so matches on the various sites
Actually GENI figured it out for us.
So now I wonder if those many other matches on this 12cM pile up area are also descended from this ancestor
Could I investigate using the new granularity on
Segment Searches (Tier 1) ?
OOPs, I see cousins on both Dad's paternal and maternal side. How might I ensure that those overlapping segments triangulate?
This way found 64 segments. My brother has this same pile up ....
A phased kit of the DNA my brother got from my father can be used!
Much better, only 54 and only the maternal 3rd cousin now
How many of you have noticed the Ancestor Projects?
Have you joined one?
You need 50+ kits to start one of your own
Clicking on it gets you this form to compare to all project kits if you are in a project
The list of projects is below that form and there is a button to request to join any of interest. Most also have FaceBook groups.
Some of the pre-existing FREE tools that I find invaluable are highlighted
Some of the pre-existing PAID tools that I find invaluable are highlighted
One of the best MKA (multi kit analysis) tools is clustering which even shows matches that have segment triangulation with a white triangle. It shows the tree icon when they have uploaded a gedcom, else an "i" in a circle; click either for a popup box with more information
(and this slide was not in the presentation at i4GG, sorry!)
The GEDcom tools were the first apps on GEDmatch before autosomal DNA, still useful
And my favorite feature, TAG GROUPS really enhances your one to many lists
