What Is Autosomal DNA Testing For Genealogy & How Far Back Can It Look?

As DNA technology has advanced, many in-depth at-home genetic testing companies have entered the market. People are flocking to these tests to understand more about themselves.

Insights gained from genetics can range to crucial health information, knowledge of predispositions to diseases, ethnicity percentages, and ancestry. 

Thanks to the rise in interest in taking genetic tests, companies are now also offering more varieties of tests. Some tests can focus specifically on your patrilineal line, while others stick to the matrilineal.

Some give health insights strictly, and others help you connect with living relatives and build your family tree.

A new breakthrough in DNA testing for genealogical purposes is called autosomal testing. This is a kind of test that looks at an individual’s autosomal chromosomes.

What are autosomal chromosomes exactly? They are the other 22 pairs of chromosomes you have that are beyond the sex-linked X and Y chromosomes. 

Keep reading to learn more about this type of genetic testing, how it’s related to genealogy, and why this might be the right test for you.

Understanding Autosomal DNA

Autosomal DNA testing is multifaceted. It doesn’t merely take your DNA to identify genealogical matches. It also can provide an overall estimate of your ethnic background and ancestry.

This test looks more closely at the segments of your genetics that are shared with anyone that person is related to. This includes, directly and indirectly, related, and both the matrilineal and patrilineal lines.

Unlike other tests, an autosomal genetic test is relevant and effective for both men and women. This is because everyone has autosomal chromosomes, so it excludes no one gender from the process.

These tests are pursued by many thanks to their ability to confirm ethnicity and close relationships with a high level of accuracy. 

How Many Generations Back?

For many, learning about your ancestors and building a family tree are the primary drivers for seeking out a genetic test.

Understanding your ancestors and their migration patterns can allow you to open up an entirely new world of understanding about your past and the people you’re related to.

It also gives you insight into how you got where you’re today. 

Austomosal tests are somewhat limited in how far back they can trace your ancestry. Typically, it’s able to provide information for five or six generations back. 

This genetic test can show you your relatively recent ancestors. Moreover, relationships that extend out to the level of second cousins are easily identified.

Once the connection extends beyond that, the percentage of accuracy in identifying third cousins decreases. 

Fourth and fifth cousins can still be identified through this testing, but the level of accuracy is less.

It’s possible that any distant matches the company reveals to you will be speculative. Therefore, you’ll need to rely on your family tree and some investigative research to fill in any holes.

Genealogy And Autosomal DNA 

Genetic tests first gained popularity when genealogy and family trees became widely popular. Of course, genealogists have been around long before DNA home-tests were, but many are relying on new technology, like autosomal tests, to deepen their work.

A genealogist might use an autosomal test to take a look at the relationship between two deceased ancestors.

If the researcher wants to know whether or not these two people were related, say as sisters, then tests from the great-grandchildren of each of them will tell the researcher whether or not they’re sisters.

Of course, no genealogy is really complete without a paper trail and some research. Sometimes insights into a family history are only available after connecting and talking to people.

Taking a genetic test can help you connect with living relatives you didn't know even existed. Furthermore, it ensures you make the connections needed to start filling in those holes in your family tree. 

 How it Works

DNA is inherited randomly. This means that your DNA is a random mixture of genes from each of your parents.

Your parents received a random mix of genes from their parents, and so on.

Each person’s DNA is uniquely their own. 

Autosomal genetic testing is capable of checking around 700,000 pairs of SNPs (single nucleotide polymorphisms) in your DNA.

From there, the testing company will compare your genetics to that of others it already has stored in its database.

From this comparison, the company should be able to identify matching segments with common SNPs.

Conclusion

Most major genetic testing companies offer autosomal DNA test kits, available in an easy-to-use at-home kit. You can order your testing kit online and receive it at your doorstep.

After submitting a simple cheek swab or saliva sample, you can mail your test back and await your results.