6 Reasons Why Taking an Autosomal DNA Test Can Bring New Insights Into Your Known Ancestry
How can taking an Autosomal DNA test bring you new insights into your known ancestry? What might you discover when you go deeper using genetic genealogy? Read on to find out how DNA can give you more understanding into your family tree.
You’ve spent hours and hours digging into documents, interviewing living relatives, or reviewing journal entries. You know your ancestral lines reasonably far back, and you feel your work, at least on some of the ancestral lines, is complete. Is there anything DNA testing can still teach you? Definitely. DNA testing can verify your hard-earned research and create a much richer family history journey. Here are six benefits of testing when your ancestry is already known:
1. Verify and Validate Documented Research With An Autosomal DNA Test
You’ve already done the hard work. You clearly understand the importance of your research to discovering your family history. In addition to using DNA evidence to break through brick walls and find new ancestors, you should consider using it to confirm known ancestors.
You will use your autosomal DNA matches within your test results at companies like MyHeritage DNA, 23andMe, FamilyTreeDNA, and AncestryDNA.
But be careful, as just having matches who also descend from your ancestor doesn’t alone prove your ancestor was your biological ancestor. A little more scientific elbow grease may do the trick. You can verify your descent from your ancestor through DNA in four steps:
- First, the DNA match should share DNA along the correct ancestral line. To ensure this, your matches should be properly sorted by identifying the ancestry match by match, beginning with your closest matches, and then carefully sorting their shared matches into groups.
- Second, the match should descend from the common ancestor through a child that is not the child you descend through. Sometimes, this is as simple as quickly verifying their attached ancestry tree showing their descent, and sometimes, this requires a bit of digging in document records. Don’t get discouraged. You’re almost there.
- Third, calculate the expected relationship with helpful tools such as DNAPainter’s Shared cM project calculator.2 This will help you determine if the amount of DNA shared with the match is appropriate for the expected relationship. The excitement of finding a match descending from the ancestor of interest means this important step gets skipped. Don’t! It is the most crucial step and can reveal incongruities in your family line, such as a previously unknown half-relationship.
- Work one generation at a time, confirming you have matches for each ancestor’s mother and father. This will help avoid any cases of misattributed parentage.
- Bonus tip! If you don’t have matches for one ancestor’s parent, find a living descendant of that parent’s sibling to test to confirm the line.
Here’s a quick checklist that will help you know if you’ve done these steps correctly:
- Does your match share DNA on the right ancestral line (as confirmed by your sorting)?
- Does the match report descent from the common ancestor, or did you find document evidence showing their descent?
- Does the match share a reasonable amount of DNA for your expected relationship?
If you can answer yes to all three of these questions, then the document evidence and the DNA evidence together likely validate that your biological lines match your documented lines, barring no endogamy, pedigree collapse, or double relationships with the match or matches.
For more information on assessing your matches, see this Legacy Tree blog post: http://www.legacytree.com/blog/determine-genetic-relationships
As a critical piece of genealogical proof, autosomal DNA results can confirm, generation by generation, all the hours of work put into documenting your lines and revealing abnormalities in your research require further exploration.
2. Discover Concealed Lines 
While you may have your genealogical ancestors pegged with document research, you might still need to learn all your biological ancestors. There may be some surprising discoveries ahead, so buckle up.
DNA tests can and likely will reveal unexpected ancestors if you go back far enough. For some, it may be a recent misattributed parentage within the first three generations of ancestors (an estimated 13 percent of us fall in this category). For others, it may be deep historical ancestry, with buried or forgotten family stories not found in documents. Most people will have at least one misattributed parentage in their family tree's first eight generations.3
Whatever the outcome of your discovery, this can be an exciting opportunity to explore a whole new side of your family history that was previously unknown.
How do you know if what you’re seeing in your DNA results points to misattributed parentage? For more information, check out this Legacy Tree blog post: http://www.legacytree.com/blog/6-signs-of-misattributed-parentage-in-your-genetic-family-tree
3. Add Descendant Lines to Complete Family Units
Focusing on your direct lines is a great first step to viewing your family history. But once that is mastered, have you tried completing each family unit, identifying your ancestors’ other descendants, and completing each family unit with the full set of siblings?
Here’s a fun example from my family history. After reviewing matches and sorting along ancestral lines, I contacted a match with no tree, sharing a little about me and my story. This match shared DNA with my family line that came to the United States from England after spending two generations in Brazil. However, this match came to the United States from England through a different migration route, spending two generations in Australia. After showing him how to order documents from England, we confirmed his great-grandmother was my great-grandfather’s younger sister. In my prior research, her document trail understandably went cold in England because she immigrated to Australia, and we did not know what had become of her. Because of our DNA results, we were able to connect and expand our family trees.
Moral of the story: there is so much breadth within each ancestral line, and DNA can help you move down, up, or side to side.
4. Collaborate with New-found Family Using An Autosomal DNA Test
Red hair, aversion to cilantro, or male-pattern baldness are all things that can be inherited from our ancestors through our DNA. But we inherit much more than genetics and tradition from our ancestors; we also inherit their stories. And, just like DNA, different stories are passed down through other ancestral lines.
Many historical brick walls and mysteries are solved by contacting and discussing ancestors with other descendants. Third cousins may know why your second-great-grandparent and her siblings were split up and raised by various extended families. Fourth cousins may know why the family followed a specific migration pattern. A family Irish cottage may come up through an exciting conversation with a newfound cousin!
I have discovered quite a few new stories by chatting with cousins I wouldn’t have otherwise known if it weren’t for DNA matching. Research into one of my great-grandfathers revealed a startling-to-us story about his mother’s death by suicide and the inquisition that followed. Years later, I connected with a second cousin, showing her what I found, but she already knew the story and shared even more information that helped me connect the dots. While my grandmother never spoke about her great-grandmother’s death to her children, my relative’s grandparent told her many details.
Documents, pictures, and other priceless artifacts can also be shared among DNA matches as they discover how they are related.
5. Helping Others
As we gain ancestral expertise, we become eager to help others explore their family history. Individuals may test to learn more about their ancestry, ethnicity percentages or find an unknown parent. One common thing, however, is that they all share an interest in learning more about their ancestry. With already-documented ancestral lines, we are ready and able to share our hard-earned research with other descendants, helping them reconnect with the ancestors you now know or helping them identify an unknown parent or grandparent.
A relative of mine died during World War II as a young mother. Her baby daughter moved with her soldier father to his home country. The daughter was geographically cut off from the family, setting up a potential genealogical dead end. But when she came within my view, we started chatting, and she welcomed the opportunity to hear the many stories I had of her mother’s father and uncles as rambunctious children in the early 1900s.
Need tips for reaching out to your DNA cousins? See this excellent Legacy Tree blog post: http://www.legacytree.com/blog/13-secrets-to-getting-replies-from-dna-cousin-matches
6. Preserving Family History Using An Autosomal DNA Test
As family history enthusiasts, we collect a fair amount of mementos that help us remember where we come from. From family bibles to treasured pictures, we love preserving the evidence of our heritage and finding ways to display it for our family to learn more. Now, consider DNA an heirloom with data that can be passed down through the generations. We know tests from older generations are more effective at finding answers. When we test, the generations after us will have the tools to solve the mysteries about our ancestors.
One simple way you can start preserving your DNA data is by inviting your older generation family members to test, and testing my husband’s aging grandmother a year before her death was invaluable. Understanding her DNA helped us discover new stories that would have been more difficult without her DNA.
How do you get started?
If you’ve never tested, consider starting at AncestryDNA, which has the largest testing database. Don’t worry, there are no needle pricks or invasive methods to collect your DNA. A simple collection of your saliva is all that’s necessary, and it is entirely done at home. Once you have started with AncestryDNA, you have full access to your data and can upload it for free to MyHeritage DNA, which has a strong international presence, Living DNA, which is strongest in the United Kingdom, and FamilyTreeDNA. Testing at 23andMe will complete access to the most extensive databases, providing the greatest likelihood of finding those key matches to confirm your lines. Adding your data to these additional databases will help you open a whole new world of new family members, stories, and more.
If you'd like help interpreting your Autosomal DNA test results, you can schedule a 45-minute consultation with one of our professional genetic genealogists here.
You might ask why I share no DNA with Carolyn’s father when my aunt does? My aunt’s DNA contained segments that either my mom did not inherit or that my mom did not pass on to me. This is why it is so important to 
