Genealogy 101: To test DNA, or not to test – that is the question

DNA testing can determine if two people are related, or descend from the same ancestor

One of the more interesting new ways to research your family tree, is to submit a sample for DNA testing.

DNA testing can determine if two people are related, or descend from the same ancestor; it can tell you if you are related to others with the same surname; and provide clues about your ethnic origin.

While DNA tests have been around for many years, it is only recently that the cost to do the testing has come within financial reach of the average person.  Currently the cost averages between $100 and $400 per test, depending on which company you ask.

If you apply for a kit, you receive the necessary bits to take a mouth swab and send it securely through the mail to the lab, and within a month or two the results are ready.

There are two main types of tests available.

Mitochondrial DNA (mtDNA) is the type of DNA passed on from the mother to both male and female children, without any mixing.  Therefore, your mtDNA is the same as your mother’s, which is the same as her mother’s, etc.  This form of DNA changes very slowly, so it isn’t as useful for determining close relationship.  For instance, if two people have an exact match, then they share a common maternal ancestor, but it is hard to determine if this is a recent ancestor, or one who lived hundreds of years ago.  It is important to note that a male’s mtDNA comes only from his mother, and is not passed on to his children.

Y-DNA, on the other hand, follows the Y chromosome in the DNA.  It is only available for males, since only males receive this chromosome.  Tiny chemical markers on the Y chromosome create distinctive patters know as haplotypes, that distinguish one male lineage from another.  Shared markers can indicate relatedness, although not to the exact degree.

Then, of course, there are the Autosomal DNA tests; this test looks at genetic markers found in the 22 chromosome pairs which contain randomly mixed DNS from both parents.  This DNA, since it it inherited from both parents and all four grandparents, can be used to test for all sorts of family ties.

So when checking around to find a price you can afford, keep in mind what types of testing the company will provide.  If you are a woman, and the site you are looking at only provides Y-DNA testing, then it is not for you.

Whether or not a DNA test is something worth doing, will depend a lot on how much information you already have, and whether such a test is likely to help fill in any blanks.  For instance, I can follow most of my dad’s tree back to the 1400’s and nearly 100 percent of them come from the same basic area of the Netherlands.  Tracing that side of the family wouldn’t likely reveal anything new worth the cost of the test.  But on my mom’s side – it could reveal a great deal, including whether or not there is any Jewish blood on her side of the family.

To learn more about genetic DNA, visit the website: www.isogg.org/wiki/Wiki_Welcome_Page, it has lots of great information.