Determining Your Ethnic Origins Through DNA Testing
By using DNA testing in conjunction with standard family ancestry research, you are able to do many things to assist in your search for long lost ancestors.
One of the more interesting things that you can do with your DNA test results is obtain a "genetic origins map" such as the one shown here. This is a copy of my own personal genetic origins map and was a bit of a surprise to me.
I fully expected the UK origins, but I was quite surprised by the diversity of my European origins. Through my prior ancestral research I knew that I had significant English, Scottish and Irish ethnicity, and possibly some French, German and Spanish DNA. However, I had no idea that I had so much Nordic DNA or that my DNA contained such high levels of Western European DNA (Swiss, German, French, etc.).
Further evaluation of my DNA by research groups (there are many university and other not for profit agencies and groups that will analize your DNA for free) indicated that some of my ancestors were possibly involved in the Crusades. As one researcher put it when comparing my DNA to that of another test subject with almost 100% Italian origin, "It looks like one of your male ancestors left his DNA in Italy, most likely while on a crusade or, less likely, someone conducting trade in the area". I think that is a polite way of saying one of my paternal ancestors left an Italian woman "with child".
By having a visual representation of your genetic ancestry, it can not only bring your genetic past to life, but also help you piece together information which may not make sense. For example, if I now start to locate distant cousins in Austria, Norway, Switzerland, etc., I know that it is very possible that the relationship is somehow valid.
Finding a common ancestor even a few generations back can be difficult so while I don't hold out much hope of finding a common relative for a 21st cousin, it may be possible one day.