By: Katy Rowe-Schurwanz

This is part one of a five-part series about what autosomal DNA is, what autosomal DNA can tell you, and how to apply autosomal DNA results to your genealogy.

Within the intricate strands of our genetic makeup lie untold stories of familial ties awaiting discovery through the precision of modern science. Join us as we journey through the origins, milestones, and strategic importance of autosomal DNA testing, revealing possibilities within genealogical research.

An intro to autosomal DNA

Autosomal DNA testing connects you to family members from your immediate family to about fifth-sixth cousins. It identifies what ancestral populations your ancestors came from. It’s a great tool to help you:

  • Find your birth family
  • Discover new cousins
  • Confirm your paper trail
  • Confirm family legends
  • Expand your family tree

When did autosomal DNA testing start?

While genetic genealogy first started in 2000, autosomal DNA tests did not come onto the market until a decade later, in 2010. FamilyTreeDNA and 23andMe offered autosomal DNA testing around the same time in 2010; Ancestry launched its autosomal test in 2012, and MyHeritage launched its autosomal test a few years later, in 2016.

Improvements to autosomal testing have occurred over the years. Companies including FamilyTreeDNA have updated their matching algorithms, added new reference populations that you can match, and released new tools for analyzing your results.

FamilyTreeDNA myOrigins map

Other autosomal tests have come and gone over the years. While it did not provide genealogical matching, National Geographic’s Genographic Project 2.0 and 2.0 Next Generation tests used autosomal testing to produce ancestral population percentages, ancient hominid percentages (like Neanderthal and Denisovan), and Y-DNA and mtDNA haplogroups.

Autosomal tests can also be used to identify your likelihood of having certain traits, like hair color and eye color, or even if you dislike cilantro. They can be used for medical diagnostics or predictive testing to determine if you have or are likely to have a certain disease. Carrier screening can look at autosomal DNA to examine your likelihood of passing down risks to your children. Paternity testing can use autosomal DNA to confirm or disprove parent/child relationships.

There can be some overlap in the autosomal locations used for medical testing and genealogical testing, but for the most part, genealogical DNA tests, including the Family Finder, are not intended to diagnose or predict any medical conditions, and should not be used for such purposes.

So, what is autosomal DNA?

Autosomal DNA is comprised of the 22 pairs of autosomes (chromosomes 1-22) that you inherit from your parents. Most autosomal DNA tests also include the X chromosome.

Chart showing male and female karyotype

These chromosomes are found within the nucleus of the cell. Each parent will pass one of each autosome to their children. Each autosome undergoes random recombination, meaning that a random mixture of the two copies of each specific autosome a parent has will be passed down to the child; so instead of getting copy 1 or copy 2 of chromosome 1 from the parent, the child gets a mixture that’s parts of both copy 1 and copy 2.

What is the X chromosome?

The X chromosome has a different inheritance pattern than the autosomes. Genetic females will inherit an X chromosome from both parents. Genetic males will inherit an X chromosome from only their mothers.

The X chromosome children inherit from their mothers will be a random recombination of their mother’s two X chromosomes, the same as for chromosomes 1-22.

The X chromosomes daughters inherit from their fathers do not go through random recombination because fathers will only have one copy of the X chromosome, so there is nothing to recombine with.

How can an autosomal DNA test help your genealogy research?

Autosomal DNA tests are one of the most important tools for genetic genealogy. Because of its inheritance pattern, autosomal DNA can cover all recent ancestral lines. By matching you to closely related individuals, autosomal DNA tests can help adoptees discover their birth families and help non-adoptees discover more about their ancestral past.

A 2022 poll conducted by Ancestry found that less than half of Americans can name all four grandparents, and only 4% of Americans can name all eight great-grandparents. These relatives are part of the foundation of your family tree. Knowledge of these relatives can help you reach back further into your ancestral past, expand your family tree, and discover how and when your family arrived in America and where they came from.

For those who already know the names of their grandparents, great-grandparents, and beyond and do know where their ancestors were from, autosomal DNA testing can confirm your genealogy research is correct by connecting you to others who share those same ancestors, and those connections can help you break brick walls and expand your family tree.

Take our Family Finder test and find DNA matches on your family tree
In the ever-evolving landscape of genetic discovery, autosomal DNA testing emerges as a cornerstone of our corporate mission, facilitating connections that transcend borders and generations. With each match and revelation, we solidify our commitment to unlocking the secrets of our shared heritage. Through the lens of autosomal DNA, we empower individuals to unravel the complexities of their ancestry, building a sense of belonging and unity within our global community.

Headshot of Katy Rowe-Schurwanz - Product Manager at FamilyTreeDNA

About the Author

Katy Rowe-Schurwanz

Product Manager at FamilyTreeDNA

Katy Rowe-Schurwanz has always been interested in genealogy, inspired by her maternal grandparents, who told her stories about their family and family history when she was little. After studying anthropology and history in college, she joined FamilyTreeDNA in 2015 and became the Trainer for Customer Support. Katy created and improved training processes and was fundamental in the creation of the Big Y Specialist team. In September 2021, she became Product Manager and has focused closely on improving FamilyTreeDNA’s genetic genealogy products.