DNA Testing and Genetic Genealogy
Recently there has been a lot of discussion in the genealogy world about the use of DNA testing for genealogy purposes. It is often times referred to as "Genetic Genealogy".
The advantage in using DNA testing for genealogy purposes is that it allows us to compare the DNA from other individuals in order to find common ancestors or places of origin.
The DNA test for genealogy is actually quite simple. Typically it involves a "swabbing" of your inner cheek with a small brush type tool. Once you've completed this step, you send your sample back to a DNA lab for analysis and then they send the test results back to you.
Many genetic genealogy DNA Test providers also maintain a database of results from other individuals that they have tested, (identified by an ID# in order to protect the identity of each individual). Many test providers also include a service which will compare your test results to others in their database in order to find a DNA match. This is usually a free service that you can opt-in or opt-out..
There are a few misconceptions about the conclusions that can be formed, based on a DNA test result, which should be clarified a bit more here.
First, a genetic genealogy DNA test is not the same type of test used for medical or investigative purposes. Therefore, a genetic genealogy DNA test will not be able to tell you if there is a common propensity for disease or other genetic defect in your family line.
Secondly, genetic genealogy testing, as performed today, will not likely tell you who your deceased ancestor is. Instead, a DNA test result comparison will only likely reveal how many generations ago that two individuals shared the most recent common ancestor or place of origin.
The biggest challenge today with the use of DNA testing for genealogy purposes is simply that because the science is so relatively new, not that many people have had a genetic genealogy test done. In addition, because of it's newness, it is unlikely that you'll find any sort of DNA test result from your ancestors.
Even though DNA results from an ancestor are not available, you may be able locate a common ancestor if you can compare genetic genealogy DNA test results from one or more related individuals. An example of this would be in the case of Thomas Jefferson's descendents. Although disputed by many Jefferson historians, the approach of using test results from related offspring was valid. If interested, you can read more the Thomas Jefferson DNA test approach at Interviews: dr. eugene foster
So what is the best use of DNA testing for genealogy purposes? The answer to this is that at this point in time, (until more individuals are tested), genetic genealogy tests results are best utilized when combined with information gathered from more traditional genealogy research methods, (i.e. record searches, etc.).
Again, your greatest odds for success when using DNA testing will be to find another living family member from a different family branch with whom you can compare a genetic genealogy DNA test in order to verify that you do indeed share a common ancestor.
What is really needed universally to make genetic genealogy a useful tool is to be able to easily combine family tree information with genetic genealogy DNA test results from individuals within that same family tree and then report those results in a universally accessible database that can be searched by name or location.