(Cross posted to all 3 lists):
Mike T. asked, "I am not familiar with FMS. Is it a more in-depth mtDNA test?"
In a nutshell, for mitochondria, yes.
The longer answer: The mtDNA molecule is only 16,569 base pairs. The Full Mitochondrial Sequence (FMS) test covers all 16,569 base pairs. Twenty years ago, they were only able to test a couple of regions on the D loop of the mtDNA molecule (That was around 1500 or 1600 base pairs only). About 10 or so years later, they were able to sequence the whole thing.
MtDNA is passed down from a mother to all her children; however, only daughters who become mothers themselves can pass it on. Anyone, male or female, can take an mtDNA test. It follows a test taker's mother's mother's mother's mother's line, or the bottom of your pedigree chart.
Because mtDNA lives outside the nucleus, it mutates very, very slowly. Once the mtDNA database reaches "critical mass," about half of your matches will be within a genealogy time frame. The other half will be much, much older and beyond the reach of a paper trail. It's not the same type of DNA as the autosomal, where you get a ton of matches and can dig right in and start to figure many matches out. MtDNA doesn't work that way. That doesn't mean not to do it, it just means you need to understand you may be in for a very long haul. I did the mtDNA on both of my parents (who both had a brick wall on that line). So far, nothing of genealogical importance has come from it yet, although I was provided with some interesting anthropological stuff. Would I order mtDNA on parents today? Yep! I'm going to leave no stone unturned in researching brick walls.
(NOTE: On an American line, I found a cousin who was into genealogy and I asked her to take an mtDNA test to lay that Native American story to rest. She took the test, and yep, it laid that story to rest).
Cheri Mello, Family Tree DNA Administrator (volunteer)