About a year ago, I had an mtDNA test performed by FamilyTreeDNA. mtDNA is short for mitochondrial DNA, which is passed from mother to daughter to daughter, ad infinitum (it is also passed from mother to son, but sons do not pass down their mother’s mtDNA). In other words, mtDNA traces the direct maternal line. In theory, this ought to offer great information; genealogy research is so often focused on paternal lines, which are easier to track using traditional paper research through the surname. However, mtDNA testing has little value for direct genealogical research; mtDNA mutates so infrequently that the test really offers anthropological information.
mtDNA results tell you which “haplogroup” your maternal line belongs to. The Family Tree DNA website explains it like this:
Specific mitochondrial haplogroups are typically found in different regions of the world, and this is due to unique population histories. In the process of spreading around the world, many populations-with their special mitochondrial haplogroups-became isolated, and specific haplogroups concentrated in geographic regions. Today, we have identified certain haplogroups that originated in Africa, Europe, Asia, the islands of the Pacific, the Americas, and even particular ethnic groups. Of course, haplogroups that are specific to one region are sometimes found in another, but this is due to recent migration.
The problem with using this information for direct genealogical research is that each haplogroup may contain millions of individuals, although it could be useful to disprove theories; for example, if family legend says that your maternal great-great grandmother was Native American, but mtDNA testing shows that your haplogroup migrated from northern Europe, then you know the legend has little basis in fact.
My results tell me that I am in haplogroup H, which Family Tree DNA describes as:
a predominantly European haplogroup that originated outside of Europe before the last glacial maximum (LGM). It first expanded in the northern Near East and southern Caucasus between 33,000 and 26,000 years ago, and later migrations from Iberia suggest it reached Europe before the LGM. It has also spread to Siberia and Inner Asia. Today, about 40% of all mitochondrial lineages in Europe are classified as haplogroup H.
Paper research tells me that my maternal lineage is German, so the mtDNA test confirms that information.