It troubles me sometimes to see how DNA companies advertise their products on television. There are several that claim they are the best at this or that but for us genealogist, particularly those just starting out want to know, how can it help my research? These types of tests are known as autosomal testing kits that will give you percentages of your ethnicity and ancient origins of your ethnicity. It is limited however in the fact that it is only helpful in determining cousins matches from both sides of your family reliably for up to about five generations.
Unfortunately for most, me included, DNA testing for genealogical purposes is a self-taught affair. We look at those ads on television and think to ourselves, "wow, it will tell me what my ancestral makeup is and where I came from." But in reality that is only the tip of the iceberg when it comes to using DNA to verify your ethnicity and genealogy. Before we get carried away and send off our hard earned money for one of these kits, we need to assess why we want to DNA test in the first place and if purchasing that kit will help us in our research.
For the Sproul project in particular I would venture to guess that the majority of us want to know where in Ulster (or Ireland prior to 1921) our immigrant ancestor came from, or for others, where or lineage plugs in to earlier branches. The two primary DNA tests that we encourage folks in our project to consider are the male only, Y-Chromosome DNA test and the male/female autosomal test commonly known as Family Finder at FTDNA.
The purpose of reviving the Sproul project was to seek out other Sproul (Sproul being the generic spelling of all variants in the project) researchers and develop a Sproul tree using yDNA testing as the primary source of data. Many of us are aware of the initial study of this project conducted by Philip Sprowl to test his theory that all Sprouls are genetically related, likely back to Walter Spreull in the late 13th century. The purpose of using yDNA is important because it is passed on thorough the male line to a son from his father, grandfather, great grandfather and so on, all the way beyond ancient human history.
This is critical if you are researching a specific lineage such as Sproul. As the descendants of Walter Spreull branched out over the many generations the yDNA remained relatively stable, to a point. What we are looking for are subtle changes to the Y-Chromosome called marker mutations. These mutations are evidence of branching and sub-branching as the generations in succession march on to the present day. As project members test we are comparing each result with other testers to see with whom they share the same mutations. The same mutations generally mean they share the same branch. The more yDNA markers you test reveals more mutations, which in turn may provide higher confidence in clues in recognizing a new sub-branch that may reveal your shared connection to the main Sproul tree.
Autosomal testing is important as well. Once we get to the point where we have high confidence that two or more people likely created a branch or sub-branch of the Sproul tree through yDNA testing, we then turn to autosomal testing. As stated earlier, autosomal testing is somewhat limited. But with additional tools from sites like Gedmatch (which also has a much larger database of cousins!) we are able to dig deeper into your autosomal data and extract matching cousin data from further back in time. This is important because your and your closest yDNA match may still be separated by 6, 7 or ever 8 generations back. These tools may help in providing more evidence as to how you are connected to you closest yDNA match and where in the Sproul tree your new branch belongs.
One word of caution; this all sounds so cut and dry but it really isn't. There are complications like intermarriage, and multiple times for a particular line throughout the genealogical period, a perceived cousin could have been an uncle, or an uncle could have been a great grandfather. The point is DNA has limitations too. It can get you close, very close. But your documentary evidence has to be spot on and one has to resolve the other. DNA is not the final word, documentary evidence is. DNA is a tool and many DNA testing options are out there.
If there is a main takeaway from this post; this is a shared effort. You cannot be a stand-alone tester and expect to get where you are going all by yourself. We are heavily dependent on other testers data. Not only DNA data but genealogical data as well. There a few project members who have no idea about their lineage. That is completely understood. But know too that we have to be proactively upgrading and communicating with our closest matches. This is a group effort that requires a ton of interaction between us all and the primary driving force behind this amazing website put together by Glen. It is another tool and if we are to be successful we must use all of our tools to their fullest capacity.