• Q: What is Y-DNA?

A: Y-DNA is the Y chromosome passed from father to son. It allows investigation into the direct paternal line, helping identify surname lines, related men, and ancestral migration routes. Only males can take the test, but women who wish to trace their "Ralston" lineage can ask a male "Ralston" relative, (father, brother, uncle, cousin, etc.) to take a test for them. (See "Can I Manage Someone Else’s Account?" below.)

• Q: How does Y-DNA testing differ from autosomal DNA testing?

A: Y-DNA traces only the direct paternal line without recombination, making it useful for deep ancestry. Autosomal DNA recombines each generation, so its signal dilutes over time. Autosomal is best for identifying a wide range of relatives but cannot trace paternal lines with precision.

• Q: I have already tested autosomal DNA. Why should I test Y-DNA?

A: The chart below shows the difference: autosomal DNA (gold) comes from all ancestors but gets split into smaller, random pieces each generation. By the time you reach 5× great-grandparents, the contribution from each is tiny and sometimes not even detectable—so you might share DNA with an eighth cousin but not with a fourth. Y-DNA (blue), however, is passed down the direct paternal line unchanged, without being divided. This makes it powerful for tracing relationships many generations back further than autosomal DNA.

• Q: What about mtDNA?

A: mtDNA is passed from mothers to all children and traces the direct maternal line. It changes little each generation but is harder to use for genealogical purposes since surnames change every generation. The Ralston Project focuses mainly on Y-DNA.

• Q: What is a Y-DNA STR marker?

A: STRs are short repeating DNA sequences. They mutate relatively quickly, making them useful for recent ancestry.

• Q: What is genetic distance?

A: Genetic distance is the count of STR differences between two men. A zero distance means an exact match. However, mutation rates vary, and factors like back mutations can mislead, so genetic distance should be used cautiously.

• Q: What is the mode value?

A: The mode is the most common STR value at a given marker within a group of men. It likely reflects the value carried by their common ancestor and serves as a reference point for comparisons.

• Q: What is a haplotype?

A: A haplotype is the specific set of STR results for one person. Haplogroups are defined by SNPs; haplotypes help distinguish subgroups within them.

• Q: How often do STR mutations occur?

A: On average, about once every few hundred generations per marker, though rates vary.
> Note: Fast‑mutating markers may cause coincidental matches:

• Q: What are SNPs?

A: SNPs are single base mutations that occur rarely and define stable haplogroups.

• Q: How do SNPs differ from STRs?

A: SNPs mutate slowly, define deep ancestral branches, and are more accurate for estimating time to most recent common ancestor (TMRCA). STRs mutate faster and are better for recent branching but less precise over long timeframes.

• Q: What is a haplogroup?

A: Haplogroups are broad paternal lineages defined by SNPs. They represent ancient branches of the Y-DNA tree.

• Q: What are subclades?

A: Subclades are smaller branches within haplogroups, defined by additional downstream SNPs.

• Q: How accurate are haplogroup trees?

A: They are reliable for timing and broad structure but lack the finer detail that STR-based trees provide.

• Q: What are private or rare SNPs?

A: These are unique to one tester or family at first. As more men test, they may be reclassified as branch-defining SNPs for subclades.

• Q: How are the extra STRs tested in Big-Y useful?

A: Big Y includes many STRs beyond Y-111. These extra markers can separate men who look the same on SNPs, add detail about recent ancestry, and provide data for building more refined phylogenetic trees. They also help identify potential new SNPs as more testers join. In short, the extra STRs give added resolution that complements the SNP results.

• Q: What factors affect accuracy in Y-DNA matching?

A: Variations in mutation rates, back mutations, parallel mutations, and occasional testing errors can complicate interpretation.

• Q: Why do I have Y-DNA matches with different surnames?

A: This is a common question that is asked when people first get their Y-DNA results. And there are several explanations for it, such as surname changes, adoptions or other non-paternity events. There are instances were children take their mother's surname. It is also possible to have a common ancestor that lived before surnames were in use. See this site for additional explanations.

• Q: What is the genealogical timeframe?

A: Roughly the last 15 generations, when genealogical records allow linking DNA results to known ancestors.

• Q: How are STRs used in Y-DNA genealogy?

A: When two or more men share the same STR mutation, it may point to a closer common ancestor and define a subgroup. But caution is needed with fast-mutating markers, since changes can also happen independently in different lines.

• Q: How are mode values used in Y-DNA analysis?

A: Mode values provide the baseline for comparing STR markers within a group. If one tester’s value differs from the mode, that usually indicates a mutation that occurred in his line after the common ancestor. When two or more men share the same deviation from the mode, it may point to a subgroup or a closer common ancestor who passed down that mutation. However, caution is needed with fast-mutating markers, since similar changes can arise independently in different lines and may not always signal a true shared branch.

• Can STRs be used to build trees?

A: Yes. Inherited STR mutations can be used to construct phylogenetic trees that show how family branches split and trace relationships over time.

• Q: What is a phylogenetic tree?

A: A phylogenetic tree is like a family tree for DNA. It shows how people or groups are related through shared mutations, with branches representing points where an ancestor passed down a new SNP or STR change. In Y-DNA testing, these trees help trace paternal lineages and show how different family lines connect through time.

• Q: Is a tree combining SNP (haplogroups) and STR data best?

A: Yes, combining SNP-based haplotrees (broad and time-anchored) with STR trees (detailed branching) gives the fullest picture.

• Q: What ethical issues should be considered?

A: Privacy, consent, sensitivity to family discoveries, and responsible sharing of genetic data.

• Q: Which test should I buy?

A: The Y-111 test provides high-resolution STR matching useful for genealogical research. The Big Y is the most comprehensive test: it places you on the SNP tree, can identify new subclades, and also tests additional STRs beyond Y-111. These extra STRs can sometimes help distinguish between closely related lines where SNPs alone haven’t yet separated them. Sales occur often, so it’s worth watching for discounts.

• Q: Can DNA tests from other companies be transferred to FTDNA?

A: Yes, autosomal tests from Ancestry and 23andMe can be uploaded. Some Y-DNA results from earlier tests can also transfer, though Ancestry no longer does Y-DNA testing.

• Q: Do I need a new kit for upgrades?

A: No. FTDNA stores DNA samples and uses them for upgrades, unless a new sample is required.

• Q: A male Ralston relative, who isn’t interested in genealogy, has agreed to take a Y-DNA test. Can I register and manage his account on FTDNA.com?

A: Yes. The account should be in your relative’s name, since it’s his DNA, but you can manage it with his permission. When ordering, enter his name and mailing address (or your own if you’ll receive the kit). Make sure he signs the Release Form so matches will appear.

If you’ll be managing the kit, use your email address so you receive the kit number and password. Share this login information with him if he wants access. Whoever receives the login credentials is responsible for managing the account.