Sunday, May 22, 2011

What DNA Test Should You Take?

DNA testing has now matured to the point that it is no longer a fad. It is another tool in the kit of a well prepared genealogist. I am often asked, “What DNA test should I take?” My response is, “What is your research hypothesis?” “What do you want to learn?” Choosing the wrong test or testing the wrong individual will lead to frustration.

There are now three basic kinds of DNA tests for genealogists to apply to research of family lines. These were described in more detail in a series of posts written about a year ago. They can still be read in the archives of this blog. Here is the condensed version: 
 1.  Y-chromosome tests can be taken by MALES to investigate their PATERNAL line. 
 2.  Mitochondrial tests can be taken by ANYONE to investigate their MATERNAL line.
 3. Autosomal tests can be taken by ANYONE to investigate relatively close relationship—say within the last 3 or 4 generations.

If you are having trouble documenting a relationship that falls within one of these three areas, a DNA test may be useful. Entry level tests  are relatively inexpensive. They may exclude someone as a possible match; but they will not conclusively confirm a relationship. By entry level I am referring to a 12 or 25 marker Y-chromosome test or a mitochondrial test that only examines hyper variable regions 1 and 2. More extensive tests will be necessary to verify a relationship.

Remember that the best person to test to answer your research question may be a carefully selected distant cousin.

One’s DNA results, taken by themselves, are relatively meaningless. It is only as they are compared with the results of other individuals and/or large databases that the findings take on genealogical significance. So choose the test and who you test wisely. Test with a company that has a large database with which you can compare your results and offers good customer service when you have questions.

For a more complete discussion of all this see Chapter 10: "Incorporating DNA Research" in my book Crash Course in Genealogy which is due out in the next month from Libraries Unlimited.

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