Wednesday, July 19, 2017

DNA with Blaine Bettinger

Blaine Bettinger has released a new book on DNA testing for genealogy titled Family Tree Guide to DNA Testing and Genetic Genealogy  It is available to borrow from the Medina Libraries. Find it on the shelves at 929.1072 BET.

It is an excellent book for those of us who have had our DNA tested for genealogical purposes.

Amy Johnson Crow, Certified Genealogist,
presenter and author, her e-book
31 Days to Better Genealogy is available on

Amy Johnson Crow interviewed Blaine for her web site and posted it HERE.

Some of the highlights of Blaine's interview are:

  1. Take ethnicity estimates with a grain of salt. Look at the continents that your ancestor came from.
  2. Dig into the DNA matches concentrating on the closest matches first (the most shared CM, which stands for centimorgans).
  3. A centimorgan is a way of measuring shared DNA. Don't bother with matches that share less than 20 CM. It is too hard to prove a connection.
  4. There are three main testing companies:
    1.  Ancestry - has an extremely large database. Because of its advertising campaign, they have a lot of novice genealogists testing.
    2. Family Tree DNA - this is the test used by hard-core genealogists.
    3. 23andMe - has a very large database, but most were tested for medical purposes.
  5. DNA testing WILL NEVER REPLACE traditional genealogy research.
  6. Contact your matches. Some of them will be able to help you build your tree.
Check out Blaine's book and his blog,  The Genetic Genealogist.

Blaine Bettinger

I used this chart from page 8 of Blaine's book to determine that our family tradition probably was false. We were repeatedly told, by multiple sources, that my great great grandmother Emily ARTIS SWAIN (shown as EAS on the chart) was 3/4 Cherokee. I have had my DNA tested as have three of my siblings. The results are 99-100% European. From the chart below, we should have inherited some DNA from Emily (and we did!) but it doesn't show any Native American ancestry.

Genetic Genealogy Chart

This Genetic Genealogy chart shows (in the light green) shows the DNA you inherit from your ancestors. Notice that as you go back to the fourth generation and further back, some of your ancestors will not contribute any DNA to you.

I have added the initials showing my paternal grandfather's line. While my siblings and I have NOT inherited 100% of our DNA from Emily ARTIS SWAIN, we all have inherited some DNA from her - about 2%. If she were 3/4 Native American, it probably would have shown in at least one of us. 

This is not 100% proof positive that there is no Native American ancestry, because the DNA we inherited from her just might not include the Native American markers, but it does make it a lot less likely. 

1 comment:

Anonymous said...

Thank you, Kat, for reviewing this book. The book has answered so
many puzzling questions I have had about my FamilyTree DNA results.
Enjoy your blog.