Who Am I? How Do I Know?

Last fall I signed up to participate in Ancestry.com's DNA project. I figured I would be in for a surprise or two. My family has not been very good at keeping a record of our history. As near as I can tell, I'm about as much a mongrel as a person can get (my kids, even more so). But the kind of surprises that showed up with the results I got last night really threw me for a loop.

WHAT DID IT SHOW:
64% Scandanavian (Norway, Sweden, Denmark)
15% Finnish/Volga/Ural (What looks to me to be a broad Russian Steppe area, following the extremely long Volga River)
14% Southern European (Spain, Portugal, Italy, Mediterranean)
7% Central European (France, Germany, Austria)

The surprise is the middle two. I knew of nothing in my family tree that could account for either of those. And at the same time, what happened to my 75% British heritage? No sign of it at all?

What I didn't understand is just what DNA tests could and couldn't do. For one thing, I'm female, which means I don't inherit the Y-DNA from my father. I do inherit mtDNA or mitochondrial DNA from my mother. If I want to know my patrilineal line, the best I could do would be to get one of my brothers to have the Y test run.

I didn't quite comprehend that the mtDNA doesn't mean lost genetic inheritance. It doesn't, in fact,have anything to do with all the non-sex-linked characteristics that have been passed down to me. It serves as a sort of genetic map that could be traced through my mother and her mother, and the entire matrilineal line back to one original woman who lived perhaps 200,000 years ago. Although my brothers received this same piece of DNA, they can't pass it on to their descendants. Likewise, since I do not have a Y chromosome, I didn't get a copy of the Y-DNA  at all, although I obviously did get lots of genetic material from my father.

So from each generation, only the mtDNA of one ancestor, through the females only, is passed down. Not father's mother. Only mother's mother. And this line shows essentially where the genetic mutations occurred over a very long period of time.

And as it happens, this maternal line is probably the least known of all my ancestry.
Nadele Mitchell (Jacobs); Nelda Norton (Mitchell); Pearl Hatton (Norton); Mary Matilda Stafford (Hatton); Nancy Garraway (Stafford); Elizabeth Moody (Garraway); Jane Grindstaff (Moody); possibly Mary Catherine Smith, or possibly Stonecypher (Grindstaff), born Rowan Co. N. Carolina, but nothing else on her parentage.

And there the trail ends, at 7 or 8 generations. I can see a path from the Carolinas to Georgia, which in that time did include Alabama and Mississippi. When territory opened up in Mississippi, and later Alabama, several branches of the family moved west. But there's nothing that shows me where this line of women originated before the Carolinas in the 18th century. Did Mary Catherine Smith's ancestry reach the Americas through the Spanish in Florida? Could they have been Viking descendants in Russia? And, most oddly for folk in the American South: Were they not English or Celtic/Anglo-Saxon at all?

A very strange and completely unexpected puzzle!