22 May 2017

DNA: What Does It Mean For Your Research



Having your DNA tested can help further researching your family tree but it is necessary to find out what you are hoping it will tell you. Testing DNA does not take the place of a thoroughly researched family tree. You will be disappointed if this is what you expect to find. There are three types of DNA tests you can have run, so decided beforehand what you are looking to find. Some companies do just one type of test, others do all of them.

Our DNA is stored in our chromosomes. We inherit 50% of our DNA from our each of our parents, they in turn inherited 50% from each of their parents. This goes back in time to the origins of man. One thing, just because we have inherited 50% of our father or mother’s DNA does not mean we inherited 25% of each grandparents’ DNA. We may inherit 10% our out maternal grandfather’s DNA and 40% of our maternal grandmother’s DNA. The inheritance does not have to be equal which is why siblings will have different DNA results and why, when we go back to 3rd cousins or further, we may not show any match. As an example, I have a confirmed 3rd cousin who does not show in my DNA matches.

There is something we find in DNA results which has been termed NPE, short for Non-Parental Event. It does happen, adoptions are not always told to children and sometimes, well, two unmarried people develop an attraction with the results that a child believes his father is his biological father but finds this is not true. Be aware of this result just in case the results are not what is expected.


Now we should talk about the various types of DNA testing which can be run. Autosomal DNA testing will give you information pertaining to the DNA you inherited from ALL your direct ancestors. It is the broadest of all the types of DNA tests. One caution, once you receive results for cousins, those who rank further back than a 4th cousin (someone who shares a 5x great grandfather with you) may be a couple of generation matches one way or the other. In other words, someone who shows up as being a 5th cousin could really be a 4th or 6th. This is one reason having a thoroughly researched tree is necessary. Also, double check the connection when you find it, be sure the other person’s tree has been reached and not just assumed or copied from a third or fourth party. This is a great test and can connect you with cousins who are will to share information, family stories and pictures. If your results show many matches without a tree they may be adoptees searching for their biological families. Some companies will also provide health information which shows up on DNA results. There are also companies who will give you (for a nominal fee) this information if you upload your raw DNA results to their website.

Another type of DNA test is the y-DNA test. Fewer companies do this type of testing. It will give you information on your direct paternal line. Only males can do this type of DNA test, females do not have y-DNA. It will show a man’s father, his father, his father on back to the direct paternal line’s haplogroup (the male clan or ancestral connection and migration).

Another type of DNA test is the Mitochondrial DNA or mt-DNA test. Fewer companies do this type of testing. It will give you information on your direct maternal line. It will show your mother, her mother, her mother on back to the “Daughters of Eve” which shows how this direct maternal line’s haplogroup (your female clan or ancestral connection and migration). Mt-DNA is only pasted done through females to their offspring. Men inherit their mother’s mitrocondrial DNA but cannot pass it down to their children.


This is very basic information on what the various DNA tests do for you. Check out the various company websites for more information but remember their objective is to sell their test. I encourage to check out various genetic genealogy blogs online and/or groups on Facebook.

After you receive the DNA test results the analyzing will need to begin before you add the information to your tree. You may need to set up your own system for adding the information to your genealogy program. I did and will explain my system for keeping track of new DNA cousins in a future post.