Do more Y-DNA STR markers improve the quality of matches’ information?

You should test more Y-chromosome DNA short tandem repeat (STR) markers when you wish to compare additional markers against others with similar results. They will refine your matches for genealogical purposes. It does not increase the number of generations traced by a Y-DNA STR test but rather reduces the range of generations in the time to a common ancestor with your match.

Testing additional STR markers can also help refine the matches in the Y-DNA – [...]

By |January 1st, 2014|Y-DNA STRs|0 Comments

Don’t we all go back to Africa?

Yes. All of our Y-chromosome lineages trace back to a common ancestor who lived in Africa at least 115,000 years ago. Some lineages migrated out of Africa; others remained.

This map shows each of the major (backbone) paternal haplogroups’ paths out of Africa.

(+ View Y-DNA Migration map)

The path that our ancestors took tells a story about human history. Testing your relatives’ and your own DNA can help you understand both the diversity and commonalities of your [...]

By |January 1st, 2014|Y-DNA STRs|0 Comments

How does the infinite allele comparison method work for palindromic markers?

For palindromic markers, the infinite allele method counts a difference for two types of changes: a mismatch and a copy number change.

Mismatches occur when the compared markers do not match. For example, the first man might have DYS464 = 14-15-15-16 and the other man might have DYS464 = 14-15-16-18. This counts as a single difference toward the two men’s genetic distance.

Palindromic copy number changes are when one male has more copies of the STR marker than [...]

By |January 1st, 2014|Y-DNA STRs|0 Comments

How many generations does a Y-chromosome DNA (Y-DNA) STR test trace?

Y-chromosome DNA (Y-DNA) tests trace both recent and distant generations. The number of generations traced by a Y-chromosome DNA test depends on the type of test taken, short tandem repeat (STR) or single nucleotide polymorphism (SNP).

STR tests are able to trace a male lineage within genealogical times and into historic times. Your genealogical connections will be shown on the Y-DNA – Matches page of your myFTDNA account. The Y-DNA – Ancestral Origins page of [...]

By |January 1st, 2014|Y-DNA STRs|0 Comments

Why do I have more than one result for an STR value? What is a multi-copy STR marker?

A multi-copy STR marker is one where there are multiple versions of the same STR in different locations on the Y-chromosome. Each STR copy changes independently. Therefore, it is typical to have different values for each copy.

For example, DYS385 usually has two copies.

By |November 1st, 2013|Y-DNA STRs|0 Comments

What is the likelihood of a non-paternal event or false paternity?

We believe that the rate of unannounced adoption or false paternity is about 1 – 3% per generation and compounds each generation. When confirming your lineage, we recommend that you test yourself and your most distantly related male ancestor to verify the line back to the common male ancestor.

By |October 31st, 2013|Y-DNA STRs|0 Comments

What is different about the STR markers DYS389I and DYS398II? Why is my DYS398II (DYS389-2) result at Family Tree DNA different from the Genographic Project?

The Y-chromosome DNA (Y-DNA) marker DYS389 is a single STR marker that has four parts: m, n, p, and q.

At Family Tree DNA we have two tests for DYS389. The first test looks at the first two parts of marker DYS389 (m and n). This is what we call DYS389I. The second test looks at all four parts of DYS389 (m, n, p, and q). This is what we call DYS389II. There are, by scientific [...]

By |October 31st, 2013|Y-DNA STRs|0 Comments

What does each short tandem repeat (STR) marker mean?

By themselves, Y-chromosome DNA (Y-DNA) short tandem repeat (STR) markers from a Y-DNA test do not have any particular meaning. The value of testing Y-DNA STR markers comes from creating a Y-DNA signature (haplotype) with them and comparing that Y-DNA signature to others in a database. They are useful for genetic genealogy because your Y-DNA signature distinguishes your paternal lineage from others. They can then be used with Family Tree DNA’s comparative database to [...]

By |October 31st, 2013|Y-DNA STRs|0 Comments

What do the DYS, DYZ, and DYF prefixes on Y-DNA STR names mean?

The DYS, DYZ, and DYF prefixes are part of the scientific name for a short tandem repeat (STR) found on the Y chromosome. STR markers are named according to guidelines published by the HUGO Gene nomenclature committee. For Y-DNA STR tests:

D stands for DNA.
Y stands for Y chromosome.
S, Z, and F stands for the complexity of the repeat segment as follows:

S is a unique segment.
Z is a number of repetitive segments at one site.

By |October 31st, 2013|Y-DNA STRs|0 Comments

Why don’t my Y-chromosome DNA (Y-DNA) test results show me percentages?

Your Y-chromosome DNA (Y-DNA) test results cannot be used to indicate your percentage of DNA from different ancestral groups. This is because tracing your Y-DNA line only leads to one origin.
Y-chromosome DNA Inheritance

1
2
3

Father’s Father

Father

Father’s Mother

You

Mother’s Father

Mother

Mother’s Mother

Y-DNA does not provide a breakdown of various ethnic origins from your other ancestral lines.

You received your Y-DNA from your father who got it from his father, who got it from his father, and so [...]

By |October 31st, 2013|Y-DNA STRs|0 Comments

If somebody doesn’t match me at 12 markers, how can they match me at a higher testing level?

Aside from their having matching turned off at the Y-DNA12 level, someone might match you at a higher testing level but not Y-DNA12 because the genetic distance is more than the amount allowed for Y-DNA12 but not the higher level.

For example, kit B193 has mismatches with kit B175 at DYS393 and DYS385. Each mismatch has a genetic distance of one for a total genetic distance of two. This is more than the amount allowed [...]

By |October 31st, 2013|Y-DNA STRs|0 Comments

If two men share a surname, how should the genetic distance at 111 Y-chromosome STR markers be interpreted?

In cultures where surnames are passed from father to son, there is additional evidence beyond a DNA match that two men who share a surname are related. Y-chromosome DNA (Y-DNA) test results should be interpreted based on both this information and the actual results.

Genetic Distance
Relationship
Interpretation
Related in This Number of Generations or LESS

Confidence

50%
90%
95%
99%

0
Very Tightly Related
A 111/111 match indicates a very close or immediate relationship. Most exact matches are [...]

By |October 31st, 2013|Y-DNA STRs|0 Comments

If two men share a surname, how should the genetic distance at 67 Y-chromosome STR markers be interpreted?

In cultures where surnames are passed from father to son, there is additional evidence beyond a DNA match that two men who share a surname are related. Y-chromosome DNA (Y-DNA) test results should be interpreted based on both this information and the actual results.

Genetic Distance
Relationship
Interpretation

0
Very Tightly Related
A 67/67 match between two men who share a common surname (or variant) means they share a common male ancestor within the genealogical time [...]

By |October 31st, 2013|Y-DNA STRs|0 Comments

If two men share a surname, how should the genetic distance at 37 Y-chromosome STR markers be interpreted?

In cultures where surnames are passed from father to son, there is additional evidence beyond a DNA match that two men who share a surname are related. Y-chromosome DNA (Y-DNA) test results should be interpreted based on both this information and the actual results.

Genetic Distance
Relationship
Interpretation

0
Very Tightly Related
A 37/37 match between two men who share a common surname (or variant) means they share a common male ancestor. Their relatedness is extremely close [...]

By |October 31st, 2013|Y-DNA STRs|0 Comments

If two men share a surname, how should the genetic distance at 25 Y-chromosome STR markers be interpreted?

In cultures where surnames are passed from father to son, there is additional evidence beyond a DNA match that two men who share a surname are related. Y-chromosome DNA (Y-DNA) test results should be interpreted based on both this information and the actual results.

Genetic Distance
Relationship
Interpretation

0
Related
A perfect 25/25 match between two men who share a surname (or variant) means they likely share a common male ancestor within the genealogical time frame. The [...]

By |October 31st, 2013|Y-DNA STRs|0 Comments

If two men share a surname, how should the genetic distance at 12 Y-chromosome STR markers be interpreted?

In cultures where surnames are passed from father to son, there is additional evidence beyond a DNA match that two men who share a surname are related. Y-chromosome DNA (Y-DNA) test results should be interpreted based on both this information and the actual results.

Genetic Distance
Relationship
Interpretation

0
Related
A perfect 12/12 match between two men who share a common surname (or variant) means they likely share a common male ancestor within the genealogical time frame. The [...]

By |October 31st, 2013|Y-DNA STRs|0 Comments

Expected Relationships with Y-DNA STR Matches

The expected relationship between you and your Y-chromosome DNA (Y-DNA) match is dependent on both the number of markers you have tested and the genetic distance. The chart below shows the interpretation of your relationship at each testing level (Y-DNA12, Y-DNA37, etc.) for relevant genetic distances.

For example, if you and your match have both tested at the Y-DNA37 level and are a 36/37 match, this is a genetic distance of one. You are then [...]

By |October 31st, 2013|Y-DNA STRs|0 Comments

Y-DNA Genetic Distance

When talking about two or more Y-chromosome STR (short tandem repeat) haplotypes, genetic distance is the total number of differences or mutations between two sets of results. In general, it is found by summing the differences between each STR marker.

For example, kit B291 and B125 have allele values of 29 and 28 respectively at DYS389II. This is a difference of 1 (29-28= 1). Because this is the only difference in their Y-DNA12 profiles (haplotypes), [...]

By |October 31st, 2013|Y-DNA STRs|0 Comments

Y-DNA Step Mutations

When comparing the results of Y-chromosome STR (short tandem repeat) tests, the difference between the two values at a marker is the Y-DNA genetic distance or the step-mutation count. That is, a one-step mutation means that the count for a single STR has changed by one. A two-step mutation means that the count for a single STR has changed by two.

For example, when comparing kit B193 and kit B173, the STR marker DYS393 has [...]

By |October 31st, 2013|Y-DNA STRs|0 Comments

Which Y-DNA STR markers does Family Tree DNA test?

At Family Tree DNA, we test 111 Y-chromosome DNA short tandem repeat (STR) markers in our standard testing panels. The chart below shows a list of all markers offered in the standard panels.

Panel
#
STR Marker
Panel
#
STR Marker

Panel 1 (Y-DNA1-12)
1
DYS393
Panel 4 (Y-DNA38-67)
61
DYS617

Panel 1 (Y-DNA1-12)
2
DYS390
Panel 4 (Y-DNA38-67)
62
DYS568

Panel 1 (Y-DNA1-12)
3
DYS19
Panel 4 (Y-DNA38-67)
63
DYS487

Panel 1 (Y-DNA1-12)
4
DYS391
Panel 4 (Y-DNA38-67)

By |October 19th, 2013|Y-DNA STRs|0 Comments

What does the WAMH badge on my personal page mean?

The Western Atlantic Modal Haplotype Match badge on the My Account – Personal Profile page of your myFTDNA account means that you match or are close to the historic Western Atlantic Modal Haplotype (WAMH) that has been reported in Y-Chromosome population genetics studies.

To be assigned the WAMH badge, Family Tree DNA
requires exact matching to one of these four haplotypes.
A genetic distance allowance is not used.

H
g
D
Y
S
3
9
3
D

By |October 19th, 2013|Y-DNA STRs|0 Comments

What does the Niall of the Nine Hostages badge on my personal page mean?

The Niall of the Nine Hostages Match badge on the My Account – Personal Profile page of your myFTDNA account means that you match exactly or are a close match to the historic Irish Modal Haplotype (IMH). The IMH was documented in a 2006 Y-Chromosome population genetics study.

H
g
D
Y
S
3
9
3
D
Y
S
3
9
0
D
Y
S
1
9
D
Y
S
3
9
1
D
Y
S

By |October 19th, 2013|Y-DNA STRs|0 Comments