Saturday, June 29, 2013

My Autosomal DNA and Gedmatch


Okay, the truth is I’ve been meaning to write some posts about my experience with using Ancestry’s autosomal DNA test.  But whoa, new information keeps being tossed my way, and like the little pin ball in Monster Bash, I keep getting bounced from one thing to the next.  


You will recall that Ancestry had given my ethnicity as 42 % Scandinavian (What!), 38% British Isles and 20% Southern European (Double What!!).  Not what my paper trail in genealogy says, but hey, I’m not a scientist. 

One of the cool things Ancestry has done (after much pressure from the Genetic Genealogy segment of the Genealogist community) is to give us access to our raw data.  Which I promptly downloaded.  I even looked at it, for all the good, it did me.  Fortunately, for me, I have an engineer Internet genealogy buddy who is way too smart for his own good, and he could look at the data and tell me things like where he and I matched. He also was smart enough to practically drag me into putting the raw data on Gedmatch. 


Gedmatch is a wonderful site for “playing” with your DNA results.  You upload your information. (Their instructions were clear enough that even a non-techie like me could do it.) Then you wait.  I don’t know how long you wait because; quite frankly, at the time I didn’t really see the value of uploading the information.  It could be days.  It could be weeks.  But about a month later, I went back, logged in and I was ready to go.


Some cool things you can do.


1.       You can predict your eye color – They came pretty close to getting the dark gray blue color of my iris correct, the gray outer circle was also right, but missed slightly on the color surrounding my pupil.  Very cool!


2.        It can predict if your parents had ancestors in common – according to Gedmatch, there is a 0% chance that my mom and dad had a common ancestor.  I haven’t found anything to contradict this.


3.       You can get a list of matches from everybody who has entered their raw data into Gedmatch.  That means not only other Ancestry DNA alumni, but also those individuals from 23 and Me, and Family Tree DNA.  Think of the possibilities. 


4.       You can compare your matches to see on which chromosomes you match, and on exactly which part of that chromosome the match occurs.


5.       You can run programs predicting your admixture (ethnicity in Ancestry speak.)


6.       Other cool things too numerous to mention.  No, trust me; if you’ve wanted to let your inner Nerd go wild, this is the place!


It’s item number five, I want to talk about today, Admixture Gedmatch style.


There are four different individuals, genetic genealogists if you will, who have contributed various admixture calculators to the website.  Three of the individuals concentrate on studying European DNA, and there is a fourth individual who focuses on Middle Eastern and Asian DNA.  They use both DNA results that have been published elsewhere, plus they have recruited participants online to fill in the gaps. 


For example, Davidski (Polako) who runs the EurogenesGenetic Ancestry Project, has created several different calculators that you can run.  With the K36 calculator you can compare your DNA to 36 different “ancestral clusters.”  For his “Pygmy” category, he used DNA donations from the Mbuti and the Biaka peoples, to give you one example of the datasets he is using to compare my DNA data.


 Below are the results that I get when I run my own DNA using the K36 calculator.

Population
Amerindian
-    
Arabian
0.31%
Armenian
-    
Basque
0.84%
Central_African
-    
Central_Euro
8.28%
East_African
-    
East_Asian
-    
East_Balkan
3.36%
East_Central_Asian
-    
East_Central_Euro
7.49%
East_Med
-    
Eastern_Euro
7.44%
Fennoscandian
7.69%
French
6.32%
Iberian
18.14%
Indo-Chinese
-    
Italian
5.94%
Malayan
-    
Near_Eastern
-    
North_African
-    
North_Atlantic
14.12%
North_Caucasian
-    
North_Sea
14.59%
Northeast_African
-    
Oceanian
-    
Omotic
-    
Pygmy
-    
Siberian
-    
South_Asian
0.47%
South_Central_Asian
-    
South_Chinese
-    
Volga-Ural
-    
West_African
-    
West_Caucasian
0.71%
West_Med
4.30%

And below is the pretty little graphic that Gedmatch made for me:

Davidski says about this calculator:


An important point to keep in mind is not to take the ancestry proportions too literary. If you're, say, English, and you get an Iberian score of 12% this doesn't actually mean you have recent ancestry from Spain or Portugal. What it means is that 12% of your alleles look typical of the reference samples classified as Iberian, and this figure might only indicate recent Iberian admixture if it's clearly higher than those of other English users.”


He also says:


“The main purpose of the Eurogenes K36 is to help users unravel the ethnic origins of local areas of their genomes (aka. half-segments), hence the high number of ancestral categories, some of which are very specific. In other words, the test is mainly a chromosome painting utility.”


 So, okay, I shouldn’t take this all too literally.  And it’s more of a tool for chromosome painting.  Huh, you say.  What is chromosome painting? In this context, Chromosome painting is a way to look at the individual chromosomes to see what the various ethnicities look like graphically on that chromosome.  If you’re not following this, it’s okay.  In my next post, we will play show and tell to give you a better idea about chromosome painting.

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