The leading consumer DNA companies provide an ethnicity report assigning our DNA to different countries or regions of the world. As a recap for those who missed the previous columns, y-DNA is passed only from father to son. Mitochondrial DNA, or mtDNA, is inherited via our maternal lines, and has specific inheritance patterns. Autosomal DNA, or atDNA, contains segments of DNA a person shares with everyone to whom they’re related, both on the maternal and paternal sides, both indirectly and directly. Everyone has autosomal chromosomes, and atDNA tests are the most often purchased consumer tests for genealogical purposes. Your atDNA reflects your ancestry from within the past five to ten generations. A generation is roughly defined as a period when a group of individuals is born and living around the same time in society, translating to about four generations per century. A previous column explained DNA inheritance and the amount passed down over time. 

Biogeographical Ancestry

A haplogroup is a genetic population of people who share a common ancestor on their motherline (matrilineal) or fatherline (patrilineal). Each haplogroup describes individual branches or closely related groups of branches on a genetic family tree of all humans. All members of a haplogroup trace their ancestry back to a single individual. Distinctive DNA markers code for specific characteristics which can be used to show the migration routes of paternal and maternal ancestors going back many generations. Your chromosomes are being categorized based on these geographic categories, showing you where your ancestors may have lived hundreds or even thousands of years ago. The scientific term for this is “biogeographical ancestry.” 

You share the same maternal haplogroup with anyone with whom you share a direct maternal line, such as your mother, sister, brother, maternal grandmother, and maternal aunt. Though men can inherit their mother’s mtDNA, they cannot pass it down to their descendants. Since yDNA is directly inherited by sons from their fathers, the fatherlines will correspond to the passing of surnames from generation to generation. However, one may discover non-paternity events (NPE) in which the genetic paternal line will be different from that of the genealogical line. Adoption, infidelity, or other circumstances contribute to the family history paper trail clashing with the genetic one. As a result, what you think you know may differ from what a DNA test reveals. 

Great 

Expectations

AncestryDNA and the other leading companies heavily market their products to those interested in their ethnic origins. Many seek a sense of identity. Others want to gain a sense of belonging. More than 30 million people have taken DNA tests. Consumer genomics is changing how we see ourselves. After viewing their results, many people will continue to identify with the group they belonged to before testing, even if the results contain unexpected information. Others will pick and choose which ethnic elements they want to incorporate into their identity. DNA tests don’t change who you are, but they can change what you believe yourself to be. 

Reality

Although AncestryDNA and MyHeritage describe their reports as “Ethnicity Estimates,” the terminology is not scientifically accurate. Ethnicity no longer synonymous with race. Ethnicity cannot be detected by DNA, but can have overlap with a person’s genetic ancestry because ethnicity is based more on social and cultural practice, which may have a basis in religion, language, or a common location.

Process

Ancestry tests are based on science designed to address questions at the population level and not at the individual level. DNA consumer testing companies use DNA samples from present-day individuals to form a panel of reference populations. These samples, collected from people with deep roots in a particular geographic location, require the individual to have four grandparents from that exact location. The samples are analyzed and put into a predefined number of clusters, removing outliers. Those clusters are named based on present-day countries or regions. There will be overlap because of historical geopolitical boundary changes. When you send your sample to be tested, your DNA is then compared to the reference populations in the testing company’s database. This is important to know because the various companies have different reference populations. If you are from a country or area for which they have no reference population, you will be matched to the next closest population. As the size of the reference populations increases over time, the results are recalculated and refined. If you submit samples to multiple companies, it is very likely the ethnicity results will not be the same.

About Native American DNA

An autosomal DNA test is better for ruling out Native American ancestry than proving it. Also, according to their website, if you cannot detect your Native American heritage, you may have inherited genetic markers that AncestryDNA does not use to identify Indigenous American ethnicity. Although 23andMe can reveal some genetic evidence of Native American ancestry, it cannot identify specific tribal affiliations.

Next time, we’ll discuss the health reports provided by the consumer testing companies. Until then, Kinseekers meets at Fairfield Glade on the first Thursday of each month from 1-3 p.m. at Christ Lutheran Church, 481 Snead Dr. in Fairfield Glade. Also, visit the Cumberland County Archives and Family Heritage Center at 95 E. 1st St., in Crossville, on Tuesdays, Thursdays, and Saturdays, for access to Ancestry.com and resources for solving your family history mysteries.