Why DNA?

By Glenn H. Landis

 

††††††††††† Why should genealogists and family historians be interested in DNA analysis?This new tool has the capability to solve thousands of problems related to the study of ancestors and relatives.Recent advances in analyzing the components of DNA have produced a bonus for genealogists, allowing us to construct a model of parts of the DNA of our ancestors and use this information to identify descendants through their DNA.

††††††††††† The DNA molecule in the nucleus of a cell is our living inheritance from our parents and the product of the combination of their DNA.This means that the DNA of each person, except for identical twins, is unique.However, one small section of the DNA molecule, the Y chromosome, is passed relatively unchanged from father to son. This piece of each cell in a man is the same as the corresponding piece in his fatherís cells and his grandfatherís and so on back to distant male ancestors.Other DNA testing is available to identify maternal ancestral lines.

††††††††††† This characteristic of inheritance of the Y chromosome means that we can identify male lines in a new and very precise way.There are many practical genealogical applications.If we suspect that the distant ancestors of two men with the same surname were brothers, we now have a test to prove or disprove that supposition.Those distant ancestral brothers, as well as all their male descendants, would have inherited the same Y chromosome identity.There are many unproven family stories of ancestors who were immigrant brothers.Descendants of the two lines could now test those theories.Any two men who have the same surname and identical test results will know that they were descended from a common ancestor even if they do not yet know the connecting lines.If one of the men has already identified many generations of his ancestors, the connection between the two can be traced more easily.The test is also helpful in the negative sense to show that one line with a certain surname is not related to another line with the same surname; in this case the results will differ widely.

††††††††††† The actual testing process is very simple.The interested person sends for a kit, swabs the inside of his cheek for a sample and returns the kit to the company.The cost of the analysis varies with the amount of information requested but is in the range of $100 to $200.Thousands of tests have been done, and the results indicate good accuracy.These tests measure nothing related to disease vulnerability or physical characteristics of the person tested.The only output of the test is a set of numbers that can be compared to those of someone else.As the number of people being tested increases, family information will increase proportionally.This test will not answer all the questions, but as the data accumulate, DNA analysis will be as important as the census, church records and other tools available to us now.

††††††††††† More information is available from the website www.familytreedna.com which is the web page of one of the companies performing the tests.The tests are slightly less expensive if they are done as a member of a family or other group.There is a Mennonite/Anabaptist group that can be viewed at www.familytreedna.com/public/menno on the internet.Two results are shown at that site for the Landis surname, and I am particularly interested in finding other Landis/Landes family members willing to participate.I can be reached at 711 Laurel Ave., Lititz, PA 17543-2928, phone (717) 627-2814 or at GlennSueL@dejazzd.com