Do you want to know how far back you can go with DNA? Here, find out how far back each type of DNA test can really take you.
There are a few different types of DNA tests available to the average person, and many different companies offering testing. How do you know which type of test you should do, and what you can realistically expect to learn from your results?
In this post, you will learn:
- How far back DNA can be traced
- Can a DNA test tell us everything about our ancestors?
- How far back Y-DNA, mtDNA, and autosomal DNA tests can take us
Most people who take a DNA test have something specific they would like to learn. In my case, I was interested in verifying or disproving a family legend about Native American ancestry, as well as learning exactly where in Europe some of my recent ancestors were from.
Some people would like to see the pie chart showing them where their ancestors were probably from, while others are looking for living family members. Still others test their DNA to research the origins of their direct-line paternal ancestry.
Can DNA results truly provide these answers for us? What are the limitations of what we can learn from our DNA results from the different types of DNA tests?
How far back can DNA be traced?
How far DNA can be traced depends on the type of DNA being tested, the type of DNA test being used, and the sensitivity of the test. Through these different categories of DNA testing, most people can discover learn about ancestors as recent as parents and learn about their direct-line maternal and paternal ancestry back as far as 150,000 and 60,000 years, respectively.
Using DNA results, we can realistically expect to discover living relatives who are descended from our recent and distant ancestors, gather evidence about who our ancestors may have been as far as 6-10 generations back in our tree, as well as learn the geographic locations of where our direct-line maternal and paternal ancestors lived tens of thousands of years ago.
When we think of types DNA testing, there are three main categories of DNA tests:
- Autosomal DNA tests
- Y-DNA tests
- mtDNA tests
Each of these individual test-types tests a different part of our DNA. For example, the autosomal DNA tests offered by companies such as Ancestry DNA and MyHeritage DNA, examine our numbered chromosomes.
Other DNA tests specialize in tracing our direct-line paternal and maternal ancestry through the testing of mitochondrial DNA (mtDNA) that we all inherited from our mothers, and that she inherited from her mother. Males can also have their Y-DNA tested to trace their father’s father’s father’s direct line.
Which type of DNA testing goes back the farthest?
The type of DNA testing that takes us back the farthest, according to most estimates, is mitochondrial DNA (mtDNA) testing. One reason that scientists can trace mtDNA back further than Y-DNA is mtDNA mutates more slowly than Y-DNA, and because we have copies of mtDNA in almost all of our cells.
This means that scientists have been able to research mtDNA more reliably in ancient DNA samples. There are many copies of mtDNA in ancient samples of humans who lived all over the world, which helps us all learn about our direct-line maternal ancestors.
In addition, only males have Y-DNA, which means that some discoveries of ancient remains do not contain Y-DNA for researchers to study. However, every human has mtDNA.
How far back does mtDNA test trace?
MtDNA testing can help us learn about our ancient maternal ancestry going back as far as 100,000-200,00 years ago to the woman from whom all humans are believed to have inherited their mitochondrial DNA (mtDNA). In addition, certain types of mtDNA testing can help us learn more specific details about our more recent direct-line maternal ancestry going back as far as 52 generations, or 1300 years.
Even though mtDNA testing does perhaps take us further than the other types of DNA testing available, we can only learn about a very small percentage (about 1%) of our ancestors using this method. In addition, depending on the type of mtDNA test we take, we may only learn about our ancient maternal ancestors and not receive very much information that is useful for genealogical purposes.
This is because some mtDNA tests can only really tell us the name of our mother’s direct-line maternal haplogroup, which can help us learn which regions of the world our mother’s maternal line came from.
The more sensitive mtDNA tests, such as the one offered by Family Tree DNA, different portions of our DNA that can allow us to understand our more recent direct-line maternal ancestry. For example, the Family Tree DNA mtDNA test can provide mtDNA matches with three levels of genetic distance, estimating that there is a 50% chance of sharing a maternal ancestor with matches at each level within the past 125, 700, and 1300 years.
It is important to mention that mtDNA tests cannot tell us the names of any of our direct-line maternal ancestors, and since most people have a difficult time tracing their female ancestors after a certain number of generations, mtDNA results can be of limited use for genealogical purposes.
How many generations does a Y-DNA test go back?
Y-DNA testing can tell us information about our ancient direct-line paternal ancestors going back as far as about 60,000-100,000 years, similar to mtDNA testing, and can help us learn about recent direct-line paternal ancestors going back as far as about 1,000 years.
Even though women cannot test their Y-DNA, as they do not have any, they can still participate in and benefit from Y-DNA testing by asking their father, brothers, uncles, or even grandfathers to take Y-DNA tests. For a female to learn about her father’s direct-line paternal ancestry, the Y-DNA test must be taken by someone who shares the same paternal line.
It is also interesting to learn about our other male ancestors’ paternal lines. For example, if we have a maternal grandfather who is willing to take a Y-DNA test, we could learn about his surname, as well as his recent and ancient direct-line paternal origins, which are also interesting to us since they are also our ancestors whether we carry their Y-DNA or not.
Similar to mtDNA testing, Y-DNA testing only covers about 1% of our ancestors. This means that Y-DNA results do not reveal anything about about 99% of our family tree.
How far back does autosomal DNA testing go?
Autosomal DNA tests, such as those sold by AncestryDNA, 23andMe, MyHeritage DNA, Family Tree DNA, and Living DNA can provide information about a broad portion of our ancestors going back as far as about 1000 years, and sometimes a bit more. These types of DNA tests are very useful for learning about very recent ancestry, too, and as such, are a popular tool for genealogists and those who like to research their family tree.
The typical autosomal DNA test provides an ethnicity or ancestry estimate that matches the DNA that we inherited from our ancestors to various regions of the world. Exactly how specific the results are depend on the company chosen.
For example, Ancestry DNA now offers about 1400 different regions and Communities in their results.
In addition to the ethnicity estimate that provides us information about where our ancestors may have lived going back as far as 1000 years, we can use our autosomal DNA results for discovering our more recent ancestry. We can even learn the exact names of who our more recent ancestors were (or are!).
By examining the family trees of our DNA matches, which is a feature provided by all of the testing companies that I mentioned above, we can identify our parents, grandparents, great-grandparents, or other ancestors even further back in our tree. In addition, we can use this information to verify our family tree research.
It is important to note that just as with Y-DNA and mtDNA, autosomal DNA is somewhat limited by patterns of DNA inheritance. Even though both males and females inherit 50% of their DNA from both of their parents, there is 50% left over from each parent that is not passed down.
This means that autosomal DNA tests can only show us results for the DNA that we did inherit, and cannot tell us anything about the DNA that we did not inherit. The solution for this “problem” is to have other family members also take autosomal DNA tests, in order to provide a more complete picture of the family’s ancestry.
I hope that this post has helped you understand more about how far back you can realistically trace your DNA using the various consumer DNA tests on the market, as well as whether DNA testing can help you verify whether you are descended from a specific ancestor.
If you have any questions about something that you have read in this post, or if you would like to share your own experience tracing your family tree with DNA, I would love for you to join the discussion below.
Thanks for reading today!