YDNA is the male DNA passed from father to son to grandson ad infinitum.
This DNA can be used to determine which male line you descend from.
Some tests such as LivingDNA or 23andMe tell you your male haplogroup type (aka haplotype) but do not provide STR values. A ‘haplotype’ is the technical name for your yDNA branch.
Haplotypes are distinct enough that when combined with dates and locations then there is a good chance of identifying the family to which that you are related.
STR Value Provide Confirmation
Shown on the right is an example of what 12 marker yDNA STR values look like.
These test results are for my own Golden family, and various male Goldens that have taken tests. As you can see, there are some differences in the matches. Differences are called ‘genetic allele distance’ — there can be differences and still a confirmation match is possible.
Only one testing service, FamilyTreeDNA.com produces a yDNA test that produces STR values which can be used to positively confirm a male to male relationship.
STR values come in 12, 25, 37, 67 and 111 markers. These markers have numerical values which are a lot like a lottery ticket. The numbers are distinctly different enough that any other male with matching values, or greatly matching, is probably related. Find a match? Jackpot!
While tests come in different marker sizes (12, 25, 37, etc) the size and the quality of the match matters. A test must match at the 37 marker level for there to be paternity-quality male-line match within the last 10 generations.
It is often not uncommon to take such a test and to get numerous 12 and 25 marker matches but not 37 marker. If someone has not taken the 37 marker test but matches at 12 or 25 then there is a chance of relationship — but it cannot be confirmed as being so.
>>> A 12 and 25 marker match does indicate an inherited kinship but it can be thousands of years in the past. A 37 marker match with one maybe two marker differences are essential for there to have been a father to son relationship within the last several hundred years.
If you take one of the popular DNA tests that tells you your haplogroup type but does not provide STR values then it is not possible to confirm that there is definitely a male to male inherited relationship within the recent past.
No Match is Not Bad News
Even if there is no known match yet, knowing your yDNA haplogroup type can be very helpful because it also eliminates non-matches from consideration as members of your male line. A G2 cannot be the father of an R1b who cannot be the father of an E-M35, etc.
A G2 father will have a G2 son who will have a G2 son, ad infinitum.
May 23, 2018: all published YDNA data from the existing Golden Patriarch YDNA Database published on WorldFamilies.net was taken down due to concerns about privacy and the impact of the then new European Union (EU) GDPR privacy regulation.
FamilyTreeDNA still makes its possible to compare STR values but it is difficult to identify and to connect with other test takers — essential to protecting your privacy.
>>> FYI: I am the FamilyTreeDNA Golden Project Administrator
Often you find a connection and yet have no clue who it is that you match.
How I can help you: I privately track DNA test results for those individuals that choose to share their test results. If you took an Ancestry or 23andMe DNA test then I can help you convert your test to find matches.
Looking for your Golden kin? Let’s chat and see if we can match your test results.