mtDNA

mtDNA Testing for Genealogy

 

The basic science:
♦  The mtDNA test can be used for testing both females and males.
♦  Only females can pass their mtDNA on to their children.
♦  The mtDNA test uses information from the mitochondria, which is the material that surrounds the chromosomes.
♦  mtDNA is passed from a mother to her children, essentially unchanged. (If there were no changes [see mutations below], each person would have exactly the same mtDNA as "Eve" and with each other.)
♦  This test is only useful in testing the participant's mother's mother's .... mother's line.
♦  All people who share the same "common ancestor" will carry essentially the same mtDNA and receive tests results that are also essentially the same.

How it works

  • The laboratory examines the DNA sample and uses standardized protocols to test the mtDNA.
  • The results are typically reported by designating only the differences to the Cambridge Reference Standard.
  • Using these differences, scientists have been able to group all people into major branches called "Haplogroups".
  • Results and matches are posted on the participants personal "myFTDNA" page at www.familytreedna.com
  • By comparing results, we can draw conclusions on which maternal lines share a common ancestor.
  • As this line changes names every generation, it is relatively difficult to track more than a few generations through genealogy.
Why mtDNA testing is useful
  • It follows only the maternal line--your mother's mother's mother's line.
  • While not as easy to trace as the yDNA surname matches, some mtDNA matches are able to identify common ancestor.
  • You will learn your maternal Haplogroup, which will tell you the ancient geographic and ethnic origins of your maternal line.
  • You will be able to join an mtDNA Haplogroup Project, to work with others who share your ancient origins.
  • You will be able to join a surname project using your mtDNA results.  Although only yDNA results are useful in a surname project, by joining you will receive updates about the project, be included in the research, and be able to submit a family pedigree.

The rules for mtDNA testing

  • Males or females can take the mtDNA test.
  • The test traces your maternal line (your mother's mother's mother's...line). 
  • You can join a Surname DNA Project if you have been mtDNA-tested, but your mtDNA results are not useful in a Surname DNA Project.
  • If you want to test for Native American or Jewish Ancestry, you must make sure the mtDNA test taker has a direct maternal line (through females only) back to the ancestor of interest. 

mtDNA Haplogroups:

  • Haplogroups are used to represent the major branch points on the mitochondrial phylogenic tree.
  • There are random and subtle changes that allow us to see differences in different "genetic families".
  • These can be arranged into a "family tree of woman" that shows the different branches that have separated over 1000s and 10,000s of years.
  • Each person today can be assigned to a Haplogroup, which tells her (or him) their "deep ancestry".
  • Haplogroups are determined by looking at mutations.
  • The letter names of the mtDNA Haplogroups run from A to Z, and were named in the order of their discovery.
  • mtDNA Haplogroups are not the same as yDNA Haplogroups.

Mutations:

  • mtDNA is passed from mother to child "essentially unchanged". However, on a random, but predictable basis for a large group, minor changes occur that we call "mutations".
  • We cannot predict when these mutations will occur in an individual family, but we do know that a mutation that occurs in one woman will be passed on to her children - and that her daughter will pass it on to their children, and so on ....
  • These mutations have occurred through the centuries, giving us the Haplogroups mentioned above,
  • These mutations occur less frequently than in yDNA, which makes them less useful in genealogy. Our genealogical paper trails usually extend a few hundred years on our maternal line, with a fortunate minority having paper trails reaching back further.
  • Many people carry mtDNA which had not experienced a mutation in the past 1000 years.

Test Options: you can be tested at different "resolution" levels.
FTDNA's information on ordering an mtDNA test