Tuesday, July 21, 2015

Spiraling Down the Double Helix

I feel like Alice tumbling down the rabbit hole.  I’m trying to get a handle on using DNA to find more cousins.

First  hurdle is understanding the terminology.  What defines a segment? What’s a Centimorgan; and why are all Centimorgans not the same “length”? SNPs? Phasing?

The good news is that every testing company has basic information about DNA and its use in Genealogy.  They’re very helpful. The user forums on these sites can be even more helpful.

And there are other great online resources for learning

Angie Bush administers a Google+ community called DNA Genetic Genealogiy Interest Community.  In August, 2015 she’ll resume doing videos and Google+ Hangouts.

23andme tested my DNA a couple of years ago when they still delivered health information gleaned from their testing. At that time, it was the health info that prompted me to test.

What’s both interesting and frustrating is that the three testing companies all use different algorithms to analyze the raw data, find matches in their database, and also show you the probable ethnic origins in your DNA. (According to 23andme, I’m 3% Neanderthal.)  You may find that a person who is high on the list of matches on one site doesn’t show up as a match on another site even though their DNA raw data is on both.

Then there’s GEDmatch which allows you to upload raw data from any of the three testing companies. You can also upload a gedcom file that will be associated with your data. also permits you to upload your raw data from Ancestry and 23and me.

I’m on a steep learning curve trying to reconcile the analyses from three sites.

My head is spinning! I still have more questions than answers.

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