Perhaps a long-held family legend dictates that you’re descended from the medieval emperor Charlemagne. You might even have genealogical records that seem to prove it. But if you’re hoping to swab your cheek to verify those ties to a European ruler born about 742 A.D., don’t bother.

Autosomal DNA – which is what most people are tested for when they use kits from genealogy companies – can only be detected five or six generations back, says Edmond pathologist and genealogist Ruth Oneson, M.D.

Autosomal DNA comes from the genes on the chromosomes one through 22. We inherit half of our genetic material from our mothers and half from our fathers. Our parents’ grandchildren only inherit 25 percent. So, for genetic testing purposes, ancestors rather quickly fall off the family tree.  It’s actually more possible to prove distant lineage through paper records than these DNA tests.

But DNA testing is still incredibly useful, says Jan Beattie, president of the Edmond Genealogical Society and a retired infectious disease microbiologist.

“I think it is invaluable for genealogy research,” she says. “You can use it to help break down brick walls. I’ve used it to both prove and disprove suspected ancestors.”

Genetic testing is no substitute for careful research, she says, “but it’s a great investigative tool that can help you find out who you are and where you came from.”

People often use the home-kit DNA tests just for fun, to discover their ethnicity breakdown, or because someone gave them a kit as a gift, says Oneson.  

“Don’t test if you don’t want to know,” she says, “because the DNA test will turn up surprises.” 

Some people find out a person they believed to be a biological relative is not. Others discover half-siblings. Beattie says she encountered someone who learned that the man who raised him was not his father. Despite the shock, he was relieved to know the truth. 

“He had always felt like he didn’t belong,” says Beattie, “and that he didn’t look like his siblings.”

Tulsa genealogist Barbara Kroll, who is a member of the Cherokee Nation, says people often get tested because they have been told they have a Native forbearer.

In most of the cases Kroll is familiar with, the DNA test does not show Native American ancestry. DNA testing does not currently show tribal affiliation, Kroll says, though that might be an addition down the road. Regardless, results cannot be used for tribal enrollment. For the Cherokee Nation, enrollment is based upon having documented ancestors on the Dawes Rolls. 

But Native Americans can use testing to learn what part of the United States their family migrated to Oklahoma from, and to discover where their white ancestors came from. Kroll’s forbearers, for example, lived in Georgia and the Carolinas and intermarried with Scottish and Irish immigrants.

Genealogy research can also help people understand their own personality traits, says Oneson, who is a member of the Daughters of the American Revolution and serves on its national DNA committee.

“In my case, my family found it better than going to a psychiatrist,” she says. “It answered some questions about family dynamics. It made us all aware of why certain behaviors existed in the family, from an event that occurred in 1894 that was a big secret.”