Have You Already Been DNA-Tested?

Ancestry Daily News
12/8/2005 - Archive

by Megan Smolenyak Smolenyak, co-author (with Ann Turner) of Trace Your Roots with DNA: Using Genetic Tests to Explore Your Family Tree

A few months ago, I was interviewed as part of an ?expert panel? on the future of genealogy. Not surprisingly, I spouted off about my confidence in the ever-growing role of genetic genealogy, which I like to condense to ?genetealogy.?

When the article came out, I received a bit of an education. Others had remarked that genetealogy wouldn?t be much of a factor until the databases of genetic data were as large as those of genealogical data -- until the entries numbered in the millions as they do at Ancestry.com, FamilySearch.org and so forth.

It was only then that I realized for the first time that many -- and possibly most -- genealogists are unaware of an important, fundamental aspect of genetealogy. While it?s true that genetic databases are measured in the thousands rather than millions, each person whose results are included is representing tens or hundreds of relatives by proxy. In other words, the DNA databases are far beefier than their absolute numbers would seem to indicate.

A Little Background
This might be a good time to back up a bit for a quick refresher. For those who are new to genetealogy, it helps to know that Y-DNA testing is by far the most popular. Only men have a Y-chromosome and it?s passed intact from father to son down through the generations. It travels through the centuries and worms its way through our family trees essentially the same way that surnames do, and that?s why surname projects are such a popular application.

Simply put, Y-DNA and surnames go hand-in-hand. Because of this, when one man gets tested, he represents a number of others sporting the same surname. His father, brothers, paternal uncles, and paternal cousins (both living and back in time through the generations) all share the same Y-DNA.

For instance, being female, I don?t have Y-DNA, so when I wanted to test the Smolenyak family I was born into, I asked my father. But I could have also turned to one of my brothers, my father?s brother, or a male Smolenyak cousin. Similarly, when I wanted to get my maternal grandmother?s maiden name (Reynolds) represented in a Reynolds surname project, I sought out a male Reynolds cousin -- in this case, a first cousin once removed -- to take the test.

One Y-DNA Test Goes a Long Way
I was curious about the ripple effect of a single DNA sample, so as an experiment, I counted how many people in my family tree were represented by proxy by my father?s test. The result? 62. Of these, 32 are alive. Of course, that figure will grow over time as I continue my research and identify other Smolenyaks -- and as fresh sprouts are added to the branches of our family tree!
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