Tracing Your Roots

Tracing your genealogy has traditionally relied on library research and paper records. Eventually, every genealogist runs into a gap in the records that prevents them from adding to the family tree. Some of those gaps can be overcome by tracing your ancestors with genetic testing.

Each of us has a unique set of DNA that is a mix of our parents genes. Your complete set of genes is your genetic profile, or genotype. Within each genotype are strands of DNA that hardly change from one generation to the next. Its these strands of DNA that make finding your roots with genetic testing possible.

When tracing your genealogy, you can use genetic genealogy tests to determine any of the following:

  • a rough estimate of your familys earliest origins
  • if two people are (or are not) related
  • if two people share a common ancestor
  • if you are related to people who share your surname
  • to confirm or deny traditional genealogical research.

Finding Your Roots with Genetic Testing

There are several options when tracing your family tree with DNA testing. Each ancestry DNA test has its own strengths and limitations.

mtDNA tests examine mitochondrial DNA, or mtDNA. mtDNA is a special type of DNA passed from a mother to her children. The mtDNA found in sperm is destroyed during fertilization. Therefore both men and women only inherit mtDNA from their mothers. mtDNA can be used to determine whether two people share a common female ancestor.

Y chromosomal DNA tests can be used to verify or deny whether two men are related. Only men carry the Y chromosome, so this test can only determine relatedness amongst men. If you are a woman tracing your family tree through the male line, you ”ll need to convince a male relative to provide a DNA sample.

Y chromosome genetic testing is very helpful if youre tracing your family tree, especially if you are of European descent. Y-DNA markers mutate, on average, once every 500 years. Europeans adopted the widespread use of surnames only 500 to 800 years ago. This coincidence makes Y-DNA tests one of the most popular choices when tracing your ancestors with genetic testing.

If you want to take the ultimate step toward finding your roots with genetic testing, consider an ancestral DNA test. This test provides you with clues to the geographic location of your earliest ancestors. Ancestral DNA tests do not provide you with proof of your ethnicity, but do provide interesting information for genealogists.

Limits to Tracing Your Ancestors with Genetic Testing

Finding your roots with genetic testing is fascinating, but its important to bear in mind the limitations of genetic genealogy. Neither mtDNA nor Y-DNA tests can tell you the exact relationship between two people. The tests can reveal whether or not two people share a common ancestor, but not who that ancestor was or when he or she lived.

For instance, a Y-DNA test may reveal that two men share an ancestor. However, whether that ancestor was their grandfather, or a man born 300 years ago, cannot be determined through the testing process.

Sometimes tracing your genealogy with DNA can produce interesting results. The one result that cant be disputed is when testing reveals no relationship. This may contradict traditional genealogical research, and can indicate anything from an unrecorded adoption to an ancestors infidelity.

Such results raise interesting and occasionally mystifying questions for genealogists; after all, isnt the search for undiscovered branches of the family tree what makes tracing your genealogy so fascinating?


Bradford, D. (2005). Genetic genealogy: Using DNA testing for family research. Retrieved November 10, 2008, from the Rootsweb Web site: