How Do I Use Maternal DNA in Genealogical Research?

Maternal DNA, or MtDNA, is helpful in determining blood relatives.

Maternal DNA or mitochondrial DNA (MtDNA) is used primarily to discover ancestors in your distant past. MtDNA is passed from mother to daughter, down through the maternal line. Mitochondrial DNA helps the family researcher determine distant maternal relatives. In order to use maternal DNA in genealogical research, it must be compared with the DNA from other women in the family.

Things You'll Need

• Family tree
• MtDNA test results
• Genealogy software

Instructions

1. Prepare or obtain a copy of the family tree. Use the tree to determine probable living descendants from a common female ancestor. Results are better if a distant ancestor such as a great-grandparent is used.

2. Contact the probable relatives and ask them to have their maternal DNA tested. To find out about your earliest female relatives, look into The Genographic Project from National Geographic.

3. Test your MtDNA and compare it with the results of the other female relatives. The results will indicate how likely it is the female relatives are all related to each other and to the common female ancestor. The test cannot determine a parent-child relationship.

4. Enter the results of all DNA tests into an online database. The provider of the DNA test usually has a secure database where the results can be compared with many other individuals. The service will notify you when there is a potential match with another individual. If that person has a similar family background, she may be a distant relative.

5. Enter the MtDNA results into a genealogy software program. Many popular programs allow the tracking of DNA test results. The results can be used as part of proving or disproving relationships. If the MtDNA from two women are an exact match, chances are they are closely related through a common female ancestor.

6. Use the results of the maternal DNA test to rule out women who are not blood relatives. The results of a maternal DNA test can be used to help identify adoptive, stepparent and other nonblood relationships within a family, as these family members are less likely to have common DNA.

Tips & Warnings

• MtDNA test results can suggest a woman and a man have the same mother because MtDNA is passed from mother to son, but it is not passed from the son to his offspring. The test is not conclusive.

• A maternal DNA test for genealogical purposes cannot be used in legal proceedings. There are very specific tests that the courts require to prove blood relationships. These tests differ from the tests used for genealogy.

References

• Ancestry Learning Center: The ABCs of MTDNA
• National Geographic: The Genographic Project

Resources

• Family Tree DNA