DNA and Research



What will Genetic Genealogy do for your research?

The term Genetic Genealogy refers to the application of science, through testing DNA, to uncover information about your ancestors. There are currently two types of tests available to the general public: the Y-DNA test and the mtDNA test. The Y-DNA test tells you about your male ancestors, and the mtDNA test tells you about your female ancestors.

The Y-DNA test is for males only as it tests the Y chromosome, which is only found in males and is inherited from the father’s direct paternal line (grandfather to father to son). Scientists have determined that the Y chromosome is passed from father to son unchanged, except for random mutations that are estimated to take place only once per 500 generations per marker.

The direct line of descent for males is critical. Events such as adoption or an extramarital male birth would break this chain. All males with a direct line of descent from your most distant known male ancestor should have the same Y chromosomal pattern, or genetic fingerprint, except for the random mutations. If you compare the genetic fingerprints of these male descendents today, they should match.

How can this help you in your research? Testing the Y chromosome can verify what is known. It can point you in a direction for further research, or prove or disprove a relationship or theory. Family Tree DNA’s Y-DNA test can find others to whom you are related. It might point you to a specific geographic location for further research. The individual reasons for doing Y-DNA testing vary significantly, from curiosity to specific genealogical research goals to large surname projects.

Here are just a few examples of the use of Y-DNA testing. For example, suppose two immigrants, who came to the U.S. in 1740, had the same surname, but you can't connect them. By testing direct male descendents of each immigrant, you can determine whether or not the two immigrants were related. In another situation, your family legend is that your surname was changed on immigration. All persons with the new surname found in the US fit into your tree. Your grandfather gave you two possible original surnames. By testing descendents of the two possible original surnames, you could determine if you were related to either. In another example, you have found your surname in New Zealand, and those people come from the same County in Ireland. By testing both groups, you can determine if they are related, and perhaps you will focus more research in this Irish county for paper records. In many cases, you may only need as few as two participants to apply Y-DNA testing to solving your genealogy brick walls or adding more information to your family history. Y-DNA Surname Projects attempt to test all lines, branches and variants of a particular surname to determine which are related. Surname Projects can start small with a subset of the surname and be expanded in phases.

The mtDNA test is available for females and for the female ancestors of males. We all carry mtDNA inherited from our mothers. Anthropologists have determined that there exist approximately 20 daughters who are descended from a single ‘mitochondrial Eve.’ Family Tree DNA’s mtDNA tests will determine from which daughter of Eve you descend. You can the use the Family Tree DNA database to find others whom you match

Reprinted with permission
Copyright 2002, Family Tree DNA, "Facts & Genes" http://www.familytreeDNA.com/facts_genes.asp



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