DNA. History. How they fit together. It's a never-ending learning process! I've compiled some of my favorite resources to help you on your journey.

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DNA Tests

One of the most-frequent questions I hear is "which DNA test is best"? There's no one-size-fits-all answer to that. If you have questions about which test(s) might be best for your particular situation, please contact me for a free consultation.

There are three major categories of DNA tests: autosomal, Y-DNA, and mitochondrial.

  • Most people start with autosomal DNA tests. These tests look at the 22 pairs of chromosomes that don't determine biological sex. Autosomal DNA is recombined at each generation, somewhat like shuffling a deck of cards. Autosomal DNA tests may help identify ancestors on any branch of your family tree going back about a handful of generations, although it gets harder to draw conclusions as you go farther back in time.
  • Y-DNA refers to the Y chromosome, which is a male-specific sex chromosome. Only those who have a Y chromosome (generally associated with being biologically male) can do Y-DNA tests. Y-DNA is passed from male to male without recombination, so it can be used to trace patrilineal relationships over long periods of time.
  • Most of our DNA exists in the nucleus of our cells, but mitochondrial DNA is an exception. This is a small, circular piece of DNA found in organelles called mitochondria that provide energy to cells. Like Y-DNA, mitochondrial DNA does not go through a recombination process. However, we each got our mitochondria from the egg cell from which we formed, so mitochondrial DNA can be used to trace matrilineal lines into deep history. Both males and females have mitochondrial DNA, but males will not pass it on to offspring.

These are some of the most popular testing companies:

Testing Company Notable Features DNA testing  *Autosomal test
*Largest database in the industry--over 6 million testers!
*Integrates with family trees
*DNA Circles, Genetic Communities, and Shared Ancestor Hints
Family Tree DNA *Autosomal test (Family Finder)
*Y-DNA tests (males only) to trace patrilineal lines
*Mitochondrial DNA tests to trace matrilineal lines into deep history
23andMe *Autosomal test
*Includes limited Y-DNA (males only) and mitochondrial results
*Get health information with a health-and-ancestry combined test or try an ancestry-only test
*Chromosome painting showing how specific segments of your DNA may have come from different places in the world
MyHeritage *Autosomal test
*Integrates with family trees at
*Currently accepting free transfers from other testing companies
Living DNA USA *Autosomal test
*Includes limited Y-DNA (males only) and mitochondrial results
*Offers greater detail on UK ancestry than any other company


I encourage you to support your local independent bookseller. Here in Seattle, I'm a big fan of Elliot Bay Book Company. But if you are going to buy from Amazon, please consider starting from here. 

If you read only one book about genetic genealogy, it should be The Family Tree Guide to DNA Testing and Genetic Genealogy by Blaine T. Bettinger. This book covers all the types of DNA testing, tools, techniques, and ethics. I've had the opportunity to study with Dr. Bettinger, and he is very skilled at making complex information accessible.

Reading  The Invisible History of the Human Race: How DNA and History Shape Our Identities and Our Futures by Christine Kenneally is one of the things that started me on this journey. This is a truly fascinating look at where science meets story.

A People's History of the United States by Howard Zinn is a classic, and something I wish had been included in my high school curriculum.

Inheritance: How Our Genes Change Our Lives and Our Lives Change Our Genes by Sharon Moalem, MD, PhD is a piece of great science writing that will change how you think about your genes.

When I was an undergraduate biology major, I learned that much of our DNA was called "junk" because it didn't code for proteins. Junk DNA: A Journey Through the Dark Matter of the Genome by Nessa Carey debunks that myth by discussing what scientists have learned about ways that so-called "junk" DNA is anything but.