For me and many other (possibly slightly crazy people) family history research is the fun part of genealogy. We all run into occasional roadblocks or brick walls that we can’t seem to get around. One early brick wall for me came when I found several of my Briggs family members trying to prove a relationship to the Mayflower. With brick walls, it is a good idea to occasionally revisit past research for new clues, and to occasionally check out the ever-changing world of genetic science, or DNA testing.
When I first heard about DNA research back in the 1990s, I thought it would soon knock over all those brick walls. Once I learned more about what DNA can, and cannot do – well let’s just say I haven’t broken down to pay for my own DNA to be tested. DNA research is a very complex entity, and at the risk of oversimplifying, I will try to explain.
Each of us is given two sets of chromosomes by our parents, which determine such things as eye and skin color, tendency to get certain cancers and other important things such as whether or not you can curl your tongue! For genealogical purposes there are three basic tests.
The first to be developed and made publicly available was the Y-DNA test. The Y-DNA test can tell you definitively if you are related through the male line to specific other males in the database. This test can take any two males and state either “yes” or “no”, whether they were related through some man specific generations ago. I had hoped to use DNA testing to confirm that Lois Vaughan, my grandfather’s great-grandmother had come from several well-documented Mayflower lines. It took me a couple of years to learn that this test would not yield the expected results since it only tested the male line, and his great-grandmother was a female.
The second test developed was the mtDNA test. It tests only the female line. So once again I was out of luck in this Mayflower quest because although my great-great-great grandmother was a female, my link was through my grandfather who was himself a male, thus breaking the chain of females. This test, as with the male DNA test (Y-DNA) can link one female to her specific ancestor if others in the line have been tested.
The third test which began to see public use in 2002 is called the autosomal DNA test. Autosomal DNA contains information from many more ancestors than does your Y-DNA (which is strictly paternal through one family line), or your maternal mtDNA. Parents pass only part of their autosomal DNA to their children, so with each generation the child picks up or forever loses some ancestral genes, so by the fourth generation ancestors quickly begin to fall off the “genetic tree.”
This means it could contain information about any of your ancestors, but won’t contain information about all of them. Each test has its uses, but is limited by whether a relative has been tested. Still one never knows when a new test will break down all those brick walls!
