Is The Y Pool Too Shallow?

On one of the lists I follow, there was some discussion recently about why some people have no matches.  Someone expressed the rather unpleasant opinion that this was “just a way to rip people off.”  I explained that when I do the Personalized DNA Reports for people, I see this regularly, even in haplogroup R1b, because of rare marker values. 

Someone else then said that “it is because the pool at present is too narrow and unfortunately for many people it is still very early yet to find any matches. . .not that it is a rip off, but you do have a marketing strategy and it is rather robust and full of promises which may not be met for another five to ten years depending on how many more people test.”

Hmmmm…..really?  I don’t think so, but let’s take a look.

First, let’s take a look at the size of the pool.  Family Tree DNA alone, not counting records from other testing companies, or the Genographic participants who did not transfer to Family Tree DNA, which I estimate is about 400,000 in total (mtdna and yline), as of October 5th, 2012, has 243,921 Y records.  Of those, 156,396 tested at 25 markers, 136,335 at 37 markers and 63,265 at 67 markers.  Not a terribly shallow pool, it would seem.

Let’s look at this another way.  The population of the US is about 311,000,000.  If you divide the quarter million people who have Y line tests at Family Tree DNA, alone, into that total, you come up with 1,244, meaning one of every 1,244 people has had their Y-line DNA tested.  If you take into consideration that approximately half of that population doesn’t have a Y chromosome that means that one of every 622 men has had their Y-line DNA tested. Of course, all of the participants aren’t from the US, but hopefully the math puts it into perspective.  Not bad for a brand new industry 12 years ago!!!

I decided to do a little scientific survey for myself.  When I do Y-line DNA reports for people, one of the things I do for them is to explain why they have the number of matches they do at each level.  This invariably has to do with both the haplogroup, subgroup and the rarity of the individual markers.  I have built a very large chart of marker frequencies for each haplogroup over the years I’ve been doing the Personalized DNA Reports.

So, let’s look at 30 people, selected at random, in no particular order.  The only selection criteria I used is that they must have tested at 37 markers or more.

In the table below, the numbers in the marker columns are the number of matches.  Blank means that the individual did not test at that level.  Zero means they did test and have no matches. 

So let’s see what we have here.

Lots of 12 marker matches.  The most for one person was 6393.  This person was fortunate though, because they had rare markers to whittle that down to 663 at 25 markers, then 42, 5 and 1, respectively on the higher panels. 

Being a WAMH (Western Atlantic Modal Haplotype), the most common 12 marker value grouping in Europe (allowing for one mutation to still be considered WAMH) means a lot of matches in the first panel, but has little influence past that.

Two people had no matches, one R1b and one T1.  When I first started doing these reports, I was surprised to see R1bs with no matches, but I probably have as many of those as all other haplogroups combined.  We think of R1b being extremely common, and it is as a whole, but there are obviously lots of pockets of rare lines out there just waiting to be discovered.

The average person has about eight hundred 12 marker matches, just under 200 25 marker matches, fourteen 37, thirteen 67 and not quite one 111 marker match.  There still aren’t a lot of folks who have tested at the 111 marker level. The good news is that if you have a 111 marker match, it’s generally a very solid genealogical match.  Most people use the 111 marker test to resolve 67 marker matches or to find line marker mutations within a family to identify specific ancestral lines.

But back to the original question.  Is this pool too shallow to produce results?  It think all of those 24,000+ people who have matches at 12 markers don’t think so.  I think the 28 of the 30 people who have matches at any level don’t think so.  The “average” guy who has matches at every level doesn’t think so.  The 2 who don’t have any matches might wonder.  I don’t think so, but I’ll let you wade in for yourself.   Does this look like a shallow pool to you or a way to rip people off?

20 thoughts on “Is The Y Pool Too Shallow?

  1. I’ve had four males tested through Family Tree DNA, representing four different family lines. They all had the 37-marker test. Two have had no matches so far, one has a match, and the fourth had a match when I entered his values in the Y-Chromosome Database of the Sorenson Molecular Genealogy Foundation.

  2. If you have one 108 of 111 marker match in a surname project of over 500 particiants, and you still can’t make the colonial era family connection, then the pool is too shallow. If you also match several lines in another surname project and can’t make that colonial connection either, then the pool is too shallow. It’s all relative. It becomes a ripoff only if the testee is promised more than can be realized in a given period, in my opinion. The science and the search has to start at the beginning and hope that more people will follow. The actual family links may never be known in many cases because of the absence of documentation.

  3. My results are very close to your analysis: 13 matches at 37 markers. Of the 13, only 9 carry the Rankin surname, and at the 1 step level I have 2 matches, but only one carries my surname. At 67 markers, I have 14 matches, but only 7 have the Rankin surname, and that includes a spelling variation (Renkin). Would you say these results are typical?

    • You’re one of the lucky ones. Some folks have matches, but not to their surname and not close enough to other surnames to draw any inferences. I’d say your matches are about “normal” in terms of how many. They either seem to be similar to yours or they have huge numbers, especially at 12 markers.

  4. Roberta – I had thought the Atlantic Modal Haplotype was limited to just one branch of R1b and did not present in both L21 and P312. I guess I’ve never understood the relationship between STRs and SNPs, if there ever was one. This might be an excellent topic for a future post. Thanks.

    By the way, today I received the National Geographic Geno2 kit.

  5. Well, since I’ve tested my father with the 37 markers and have no matches yet, I’d like to believe the pool is just too shallow and we will get our money’s worth some day with the Y-dna test. Although I have to say I’m a little pleased with the Family Finder test (we have found one 5th cousin match on his mother’s side). In the end I’m glad I had our DNA tested, but I wouldn’t recommend the test to friends with the results I’ve had, unless the prices were lower of course. I feel as though I pretty much took a gamble, and am still waiting for the results.

  6. When looking at Y-DNA matches, I think a better way to look at this question is from one of Y-SNP probabilities for USA men being tested by FTDNA. Here is mine for Y-SNP R-L371 http://tech.groups.yahoo.com/group/RL371/

    1. To the best I can determine there are about 250 men in the FTDNA database which have been tested R-L371+ (20) or can be predicted R-L371 (230) because they meet the R-17-14-10 Marker criteria.
    2. There are about 250,000 men (primarily from USA) who have been Y-DNA tested by FTDNA.
    3. 250/250000 = .1% or about 1 out of every 1000 Y-DNA tested men at FTDNA will be R-L371.
    4. From this .1% group I know only 10% of those men will be in my Griffith – Jones clan. So, know the probability for me finding some close Y-DNA ancestors is 1 out of every 10000 Y-DNA tested men at FTDNA
    5. R-L21 is upstream and has 10 “Son” Y-SNPs under it including R-L371 in position 8 as R1b1a2a1a1b3a8. If someone is R-L21, there is about a 1.05% probability they will be R-L371.
    So, yes the Y-Pool is shallow for me …. but there are ways around that!

    • Interesting. But your analysis above does not include the haplotype STR matches referenced in this post. As I understand it, SNPs better reflect deep ancestry rather than recent geneological relationships. In my situation, the very few SNP matches don’t correlate at all with the STR matches. Thus, my suggestion above to Roberta seeking a more professional explanation for the relationship between SNPs and STRs. There may not be any at all, and only STRs may be relevant for geneological purposes. I honestly don’t know at this point.

      • Max, NO! A Y-SNP does not always reflect or equate to “deep ancestry”.

        Y-SNPs are more stable and informative than a fast mutating Y-STR marker. I suggest you do some self study on this at http://www.isogg.org/wiki/Y_chromosome_DNA_test as well as reading some books in this area.

        The Y-SNP R-L371 is young with origins circa 1000AD to 1100AD. Given that fact and also since it is a “Terminal SNP” it is exceptionally relevant in determining Genetic Genealogy relationships.

        I have over 1800 Y-STR12 matches and matching at 12 Y-STR markers with a GD=0 is irrelevant Genetic Genealogy garbage to experienced and knowledgeable Genetic Genealogists.

        The general rule of thumb by FTDNA charts is that a 12 of 12 Y-STR match means you “could” share a common ancestor with your match extending to about 29 generations back in the past (95% probability). That’s about 900 years back.

        The Y-SNP, R-L371, has a unique Y-STR Signature / Fingerprint called R-17-14-10 on 3 Y-STR markers. The frequency of “17” for DYS448 is rare … but informative. With a “17” there you have a 30% profitability of being a R-L371. Add that to a “14” at DYS456 and the probability goes to 90%.

        Here’s the essence of what I am saying: Yes, certain Y-STR markers are more informative than others. Have you went through that exercise to determine which Y-STR markers are more informative to you? A big thing FTDNA could do is let people find matches on their more informative markers such as can be done at YSearch and other websites.

        Max, with the Geno 2.0 test you may get lucky and find your Y-SNP Terminal Haplogroup or maybe a Y-SNP at one level up. Each year or two they will be adding new Y-SNPs to their chip. So, if not now … then retest with Geno 3.0 in 2 or 3 years.

        In the mean time, if you have not already done so, take a 111 Marker Y-STR test and try to determine your Y-STR Signature on 5 to 7 highly informative markers.

      • These are not SNP matches, but STR matches. I included the haplogroup and the terminal SNP so that people could see which haplogroups had the most and which the least matches. Case in point is that many people presume that R1b always has matches, and that just isn’t true. SNPs and STRs are both valuable, depending on the situation at hand. I will talk more about SNPs and STRs in a future post.

  7. Thanks for the reply, George. I’ve actually been testing quite a bit with FTDNA since 2006 and the first Genographic Project. I learned very early on that a 12-marker STR test (which came with the first Geno) is of little help, and later tested 25, 37 and 67. I also took the deep clade SNP test and was found to share a “private” SNP, L147.3, with just two others who have tested so far. This is way down the tree too, although I hadn’t heard the term “terminal” before. The point I was making was that notwithstanding this shared private SNP, one other L147.3 person shared only 54 out of 67 STR markers, and estimated our MRCA at 811 AD, not exactly helpful for genealogical purposes.

    I think you’re fortunate to have identified a group that shares not just a rare SNP but also a few apparently rare STR markers, although 1100 AD still leaves you with some 36 generations of ancestors, more I’m sure than the entire population of Wales. I’m still waiting for a match at 25.

    Good luck in your quest.

    Mark

  8. My Grouling / Grauling cousin has 1501 twelve marker matches, and zero 25, zero 37. He is the first of his surname to be tested and it is a true rare surname. Now I want more to test. Come on, I’m ready for another sale. Thanks for your article.

  9. I just had my male Roling cousin tested ( 37 markers) for my paternal side Results just came back and he has 0 matches period – not even a single match at the 12 marker level. No matches at all. They can’t even venture a guess as to probable haplogroup. I know the surname is rare but still, I do find that a bit strange. Aren’t there certain SNP markers that can at least give an indication as to a person’s haplogroup?

    • If Family Tree DNA cannot predict your haplogroup based on matches with people who are SNP tested, they will SNP test your sample for free to determine at least a base haplogroup. Just ask customer service for this.

  10. Pingback: DNAeXplain Archives – Historical or Obsolete Articles | DNAeXplained – Genetic Genealogy

  11. searching for my maternal grandfather’s father, he was born out of wedlock and given his mother’s maiden surname…..FTDNA YDNA 37 markers tested on my only remaining 1st male cousin……many matches resulted with a surname that is very prominent in the county he and his mother were born in, (0 genetic distance at 25 markers and 1 genetic distance at 37 markers)……I have talked with both of the “closest” matches and living male relatives of theirs are willing to do further testing and (these two men come from the same great great grandfather)……what test do I run next and on who…..67 markers on the 25 marker match line or 111 on which match……I am still trying to narrow down the sons of the two great grandfathers …

    • Test the men for the Y chromosome, of course, then test the same men autosomally. You may match one more closely than the other which may provide guidance for which son was the father – or maybe a different son.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s