DNA for Genealogy & Adoptions

By Shane Jones, Master Genealogist and DNA Consultant

How accurate is a DNA Test?

The biggest point, that Major Companies selling DNA kits for Genealogy won’t tell you is, DNA for Genealogy is NOT an EXACT Science.

Is there a difference between a DNA test for Genealogy and a Paternity Test?

The answer is yes! A court will accept a Paternity Test from a Certified Company, whereas, a DNA test has a lot less or no weight in Court. This should tell you a lot about the accuracy of DNA Tests! DNA experts talk of Mutations in a line. So what does all this mean to you the Amateur Genealogist? It means that DNA tests should be used as a Guide only, until you find supporting facts. This includes Adoptions and looking for Native American Ancestry. The safest way to do this is to hire a company who has a specialist in Using DNA testing specifically for Genealogy.


Which DNA Company should you use and why?

You should consult a DNA expert before ordering a DNA Kit. This will enable you to order the right test for your specific objective. Yes! There are many types of DNA tests.

If you want to find relatives or overcome a brick wall on a particular ancestral line, invoke reverse genealogy, or find biological ancestors when there is an adoption involved, it is always a good option to choose multiple companies to do DNA testing with. This is most important for one reason. There are many DNA testing companies. Like most people you would never have heard the names of most of the DNA companies. Therefore, for practicality, you should order what the experts call, “The Baseball Effect.” This means that you should order tests from the four DNA companies that allow a Family Tree to be connected to the test. These four companies consist of over 95% of all DNA testing for Genealogy. It is important to do at least one test from each company. If you don’t have a DNA test from each of these companies you run the risk of having the match you need, being in one of the other DNA companies. If you were adopted, and you are looking for a biological link, if you take a test from one company, and your biological relative takes a test from a different company, you will not find them. This is why it is critical to have “The Baseball Effect” and cover all four bases.

The purpose of DNA testing in regard to Genealogy is fourfold.

  1. To find living relatives
  2. To find someone living who has a common ancestor with you who may have additional information on your family.

  3. To find a common ancestor that you cannot link to. This means that you have a DNA match with someone else who has taken the same DNA test. As an example: Gerry obtains a match 8 generations back on his Dudley line. However, Gerry can only go back on the Dudley line 6 generations. Hence, he knows that the 8th generation match is the grandfather of his 6th generation ancestor but, Gerry doesn’t know the name of the 7th generation ancestor. This allows for some Reverse Genealogy. Gerry would start his research with the 8th Generation ancestor and try to discover all the children’s names of the 8th generation ancestor and learn all about them and where they lived and migrated to, until he finds a match for the father of the 6th Generation ancestor.
  4. To overcome an adoption situation.


About the Author

I have been used as a Consultant by many people including Ancestry.com and FamilySearch. Some of these included teleconferences with Ancestry’s Leading DNA Scientists in San Francisco. I have also consulted with World Leading DNA Scientists. I have also been involved with Genetic Genealogy for over 25 years.


Shane Jones