Mission 11: The Spit Test — DNA Testing & Genetic Genealogy
The paper trail told us who they were. The spit test tells us where they came from.
We’ve been digging through paper trails for months: certificates, census pages, and microfilm squinting. Then someone in the family—always someone—asks, “Have you tried the spit test?”
Reader, we tried the spit test.
I was skeptical. We’ve been doing serious genealogy here: documents, records, and sources you can cite. Mailing away a tube of saliva and getting a pie chart felt like carnival genealogy.
What I didn’t understand is that the pie chart is just the party favor. The real work starts when you gain access to your DNA matches. Those matches can break open brick walls no census record ever could.
This mission is your onramp. We’re not going deep today—we’re going in: far enough to understand what DNA testing is, which kit to buy, and what to expect when the results arrive. If you’ve already tested and your results have been sitting there unexamined, you’ll know what to do next.
What Is a DNA Genealogy Test, Actually?
There are three types of DNA tests used in genealogy. Most beginner confusion comes from not knowing which one they’re dealing with.
Autosomal DNA is what every commercial genealogy kit uses. It tests DNA inherited from ancestors on both sides of your family and compares it against the company’s database. You receive an ethnicity estimate—the pie chart—and a list of living people who share DNA with you. This is where beginners start.
Y-DNA traces the direct paternal line: your father, his father, and his father’s father. Only men can take it, though women can recruit a male relative. It is used for deep surname and paternal-line research rather than general tree building.
Mitochondrial DNA, or mtDNA, traces the direct maternal line. Anyone can take it, and it too is a specialty tool. File Y-DNA and mtDNA under “useful later.” Right now: autosomal.
With autosomal testing, you provide a saliva sample. The laboratory examines markers across your genome, compares them to reference populations to estimate ethnicity, and compares them to other customers to create your match list. The process usually takes three to eight weeks.
Which Kit Should You Buy?
This is where Granny gets direct: start with AncestryDNA.
Database size matters. Your match list is useful only if the people you’re related to have also tested. AncestryDNA has the largest genealogy DNA database, and it integrates match results with a vast collection of family trees and historical records. That makes moving from “I share DNA with this person” to “let me inspect their family tree” much easier.
Kits are often discounted around holidays. You don’t have to test today; wait for a sale if that helps.
If your ancestry is primarily European—particularly Scandinavian, Eastern European, or Middle Eastern—MyHeritage DNA is a strong alternative with broader international representation. MyHeritage also accepts raw DNA uploads from other services, so you can test at Ancestry first and then expand your match reach.
FamilyTreeDNA is where you may eventually go for Y-DNA or mtDNA. Its autosomal database is smaller, so it isn’t Granny’s first recommendation for general cousin matching.
Then there’s 23andMe. Before sending any company your genetic data, review its current ownership, privacy terms, data-retention policy, and genealogy features. Choose a service whose tradeoffs you understand and accept.
Granny says:
“The paper trail told us who they were. The spit test tells us where they came from. Between the two, you might just figure out the whole story.”
What Happens After the Spit
You order a kit online. Inside is a collection tube. You provide a saliva sample, register the barcode so the company can tie the kit to your account, seal it in the return package, and mail it back. Then you wait.
Three to eight weeks later, your results are ready.
The ethnicity estimate appears first. It’s colorful and also the most misunderstood feature in genetic genealogy. This is a statistical estimate, not a certified fact. It is based on reference populations that change over time. Different companies can report different percentages for the same sample. A surprising region is a conversation starter, not a conclusion. Treat the estimate as interesting data; don’t stake your identity on it.
The DNA matches are where serious genealogy begins. This is a list of living people who share DNA with you, ranked by estimated relationship. In a large database, you may have hundreds of matches. Most will be distant; a handful may be close enough to help with active research.
Tools built around the match list—shared matches, clustering, and linked family trees—turn raw data into genealogy. When a match has attached a tree, you can look for overlapping surnames and places. When you recognize a branch, you’ve found a connection. Sometimes that connection breaks a wall documentary research alone could not.
Manage your expectations. DNA genealogy is a long game. Most beginners won’t solve a mystery in the first week. Think of it as you would census records and vital certificates: each piece of evidence adds to the picture. DNA is simply a very wet piece of evidence you mailed away in a tube.
Your Mission
Test. That is the mission.
If you haven’t yet, choose a service whose database, privacy terms, tools, and geographic strengths fit your goals. While you wait, review your family tree for brick walls—places where the paper trail goes cold. Write them down. When the match list arrives, those are the branches where a match with an attached tree might light the way.
If you’ve already tested and haven’t looked at your match list lately, go back. Check whether new matches have appeared or existing matches have added family trees. The databases grow every day.