Father’s Day is on Sunday, 19 June 2022, in the United States, you may be interested in giving a gift to a father in your life, and I have a fun idea for you! Family Tree DNA (FTDNA) has Y-DNA kits on sale right now. You can save money on each of the three Y-DNA kits that FTDNA has available.
You may have questions about Y-DNA, and hopefully, I can answer some of them in this blog post.
What is Y-DNA?
The DNA in the Y-chromosome is called Y-DNA. Human males are born with an X and a Y-chromosome and 22 sets of autosomes, numbered 1-22, whereas human females have two X-chromosomes and 22 sets of autosomes. Y-DNA has a unique inheritance pattern; fathers pass it to their sons, who give it to their sons, and so on through the generations. The ancestor you share with a Y-DNA match may have lived recently or hundreds or more years ago. There is a slow mutation rate in Y-DNA.
Y-DNA tests assess how many times a short sequence of DNA repeats at specific locations (called markers) along the Y-chromosome. The Y-37 test looks at 37 sites (called markers) where short tandem repeats (STRs) occur in the Y-chromosome. The Y-111 examines 111 markers, and the Big Y-700 looks at 700 STRs as well as 200,000 single nucleotide polymorphisms (SNPs) along the Y-chromosome.
When there is a mutation in the number of repeated motifs, and the number differs from the number that a Y-DNA match has at that marker, the DNA match list states the Genetic Distance between you and your DNA match. Family Tree DNA defines Genetic Distance as follows:
“There are two meanings for Genetic Distance:
- Genetic Distance is the number of differences, or mutations, between two sets of results. A genetic distance of zero means there are no differences in the results being compared against one another, i.e., an exact match. This is the meaning when comparing Y-chromosome DNA or mitochondrial DNA.
- For autosomal DNA comparisons, genetic distance may refer to the size of a DNA segment. The genetic distance is then the length of the segment in centiMorgans.”
This table indicates the maximum Genetic Distance that is reported at a specific DNA test level.
The image below illustrates Y-DNA inheritance for five generations of a family. Square shapes represent males, and circles represent females. The black squares indicate males who inherited Y-DNA from the father/grandfather at the top of the chart.
Why should men take a Y-DNA test?
A Y-DNA test can tell you about your patrilineal ancestors. The Y-chromosome is passed on virtually unchanged from fathers to sons for many generations. Family Tree DNA has a database of Y-DNA testers, and when you take a test, you can learn who else shares a patrilineal ancestor with you. If you’re looking for your patrilineal ancestors and you don’t have a Y-chromosome, ask a close relative who descends from the patrilineal line you are interested in to take a Y-DNA test.
What a Y-DNA test can tell you:
- The Y-DNA tester’s haplogroup -this is the Y-DNA name of a group of descendants from a shared patrilineal ancestor
- You are related to a DNA match through a shared patrilineal ancestor
- The Genetic Distance between the tester and the DNA match
What it cannot tell you
- The specific ancestor you share with your DNA match
- Exactly how many generations are between you and your shared patrilineal ancestor
What Y-DNA marker level should I test?
I recommend testing as many markers as you can afford because if you have DNA matches at higher marker levels, it means that you are more closely related to the DNA match.
- Start with 37 markers; you can upgrade the test later to Y-111 or Big Y-700
- FTDNA sends an email when you have a new Y-DNA match and tells you how many markers you match
Join a Y-DNA Surname project
After you receive the Y-DNA results, join a Y-DNA Surname Project. A Surname Project may have a few or may have hundreds of people who are interested in ancestors with specific surnames. One advantage to a surname project is that you can see other Y-DNA test results and compare them to yours even if you and specific testers aren’t a close match.
What if the surnames of my DNA matches are different than mine?
- Don’t panic – it’s possible that the DNA match may not have the expected surname, or no one from your line has tested yet
- There could be an undocumented adoption or a misattributed parentage event somewhere back along the ancestral line. This could have occurred many generations ago
Not only can a Y-DNA test be a novelty for some people, it can also help you find answers to some family history mysteries along your patrilineal line. Wishing everyone a Happy Father’s Day, and best wishes with your Y-DNA research!
 “Glossary Terms, Genetic Distance” Family Tree DNA ( https://help.familytreedna.com/hc/en-us/articles/4418230173967#g-0-6: accessed 11 June 2022).