Big Y Matches disappeared

[WLGreene55]

I got a gripe. In the old Big Y, I had 800+ matches. After the results of the new Big Y came in, all my 800+ matches disappeared except for 2. These 2 matches don't know anything about their ancestral origins. They can't trace their tree back to Europe. They can't help me find my paternal origins.

I discovered from the old Big Y matches that I was Irish, Scottish & Welsh. I didn't know that before I took the test.

Are those 800+ matches coming back or are the gone forever??

My haplogroup R-Z39589 is a very large group. There should be some matches from it in my Big Y.

This is somewhat disappointing to have 800+ matches disappear.

Haplogroup R1b>L21>DF13>Z39589>FGC13780>FGC13785.


Wayne Greene
Kit 6799

[Armando]

A threshold of 30 non-matching variants (SNPs) has been added to the matching algorithm. If you have more than that limit with anyone then they won't show as a BigY match. That means that all of your BigY matches that disappeared do not share a common ancestor with you in the direct paternal line further back in time than your current BigY matches. Your BigY matches that aren't Y67 or Y111 matches, if you and they had those tests, are unlikely to have a common ancestor with you in the direct paternal line in a genealogical time period.

Having only matches that are from a more recent time period is something some people prefer since it allows more privacy.

The threshold for matching was supposed to be 40 non-matching variants but it looks like 30 is the limit based on what has been reported at Anthrogenica.

[WLGreene55]

Armando, Thank for the reply. I understand what you are saying. It helped. Big Y is useless for people in newly discovered SNPs if FTDNA confines your matches to your SNP. They wouldn't get a broad picture of who they were related to. There are only 2 other guys in my parent SNP FGC13780 and they do not show up in my Big Y matches. So far the new Big Y is disappointing.

[The_Contemplator]

Distant old Big Y matches having a specific origin may also be misleading. They may have known their origin but your shared ancestor could have predated that by being from a different region altogether. So your ancestors could have not even been from the place your old matches pegged their ancestors to be from.

With Big Y, it helps to recruit some of your STR matches. In one kit I manage, I was the first to order the Big Y. Got 9 others STR matches to take it so far. Things are finally coming into view with that research group.

[WLGreene55]

Thanks for the info. The old 800+ matches had one thing in common. They were SNP CTS3937+ which is what I am positive for.

My dna is rare: DYS385 a/b = 11-11; DYS389II = 28; CDY = 37,40.

I have very few Ydna matches (not like you do) and I don't have any matches with people in my own surname. Tried to recruit some of them for the Big Y but they are not interested in it. The cost of the test seems to be a big drawback for a lot of people. Some of my Ydna matches are NPE's or are adopted.

I agree with what you said about the matches but the old matches gave me an overall idea of my ethnicity.

[Armando]

The cost of the test seems to be a big drawback for a lot of people.

Yes it is a very big drawback apart from the fact that Y111 STR matches are normally from a more recent time frame than BigY matches. Since most people are more interested in a genealogical timeframe they are more interested in STR matches. The relatively extremely small number of BigY tested people is definitely another problem which is a result of the cost and lack of interest. Even STR testing is only a very small percentage of people that get autosomal testing with all of the DNA testing companies.

I agree with what you said about the matches but the old matches gave me an overall idea of my ethnicity.

If enough BigY tested people with well documented ancestry join YFull, and for P312 people, the BigTree by Alex Williamson, and put the country of origin of their most distant direct paternal ancestor then you can see the countries that each SNP is found in as you go upstream in the phylogenetic tree. There needs to be a lot more BigY tested people before this is very informative. The BigY matching at FTDNA suffers the same problem with not enough BigY tested people.

For instance CTS3937 is at http://www.ytree.net/DisplayTree.php?blockID=17. There is no country for those 3 people. If you go upstream to FGC13780 then there is only one person with a country. If you go upstream one more step which is Z39589 at http://www.ytree.net/DisplayTree.php?blockID=1254 then you can see that the SNP is found in many different countries.

The old 800+ matches had one thing in common. They were SNP CTS3937+ which is what I am positive for.

The BigTree is a very popular site and it is free but it only has 3 people that are positive for CTS3937. CTS3937 and FGC13785 are phylogenetic equivalents and the L21 haplogroup project results only shows 3 people to positive for FGC13785 and they are under the group 5800. FGC13780+ L21>DF13>Z39589>FGC13780 (Consider Big Y, R1b-L21 SNP Pack, 111 STRs)* and they are the exact same 3 people in the BigTree. It is impossible that you had 800+ BigY matches that were all positive for CTS3937. You obviously weren't looking at the match list correctly. There used to be a drop down box where you could select only matches that had your terminal SNP much like the new algorithm does now. That is what you were supposed to be doing. All of the 800+ matches that you had were L21 people or DF13 and not just CTS3937+ people.

[Ric]

A threshold of 30 non-matching variants (SNPs) has been added to the matching algorithm. If you have more than that limit with anyone then they won't show as a BigY match. That means that all of your BigY matches that disappeared do not share a common ancestor with you in the direct paternal line further back in time than your current BigY matches. Your BigY matches that aren't Y67 or Y111 matches, if you and they had those tests, are unlikely to have a common ancestor with you in the direct paternal line in a genealogical time period.

Having only matches that are from a more recent time period is something some people prefer since it allows more privacy.

The threshold for matching was supposed to be 40 non-matching variants but it looks like 30 is the limit based on what has been reported at Anthrogenica.

What's the point of reducing to 30 and remove all the matches, to frustrate and make the customer angry with zero matches ?
Similarly, about the algorithms for the STR matchs, I have argued in the df27 group that the current thresholds used, such as GD=2 for 25 level, are totally unsuited for the unfortunate people with very off modal values. And there are a lot of them. So, if you get a very high GD from the mode on a single STR, that basically disqualifies you for matching anybody depending on when the mutation occurred. Remove that particular STR, or input the Mode instead, and you'll get matches again, in addition of a happy customer.

So now in addition to the STR frustration, we'll get the BigY frustration.
Hmm, I suggest to put the limit at 5 different SNPs. It would surely ensure an even closer relationship...with nobody.

[spruithean]

What's the point of reducing to 30 and remove all the matches, to frustrate and make the customer angry with zero matches ?
Similarly, about the algorithms for the STR matchs, I have argued in the df27 group that the current thresholds used, such as GD=2 for 25 level, are totally unsuited for the unfortunate people with very off modal values. And there are a lot of them. So, if you get a very high GD from the mode on a single STR, that basically disqualifies you for matching anybody depending on when the mutation occurred. Remove that particular STR, or input the Mode instead, and you'll get matches again, in addition of a happy customer.

So now in addition to the STR frustration, we'll get the BigY frustration.
Hmm, I suggest to put the limit at 5 different SNPs. It would surely ensure an even closer relationship...with nobody.

The point is to allow for whatever matches you may get to be more relevant than the ones older than 4300 years. I'm not sure I'd be a happy customer if the majority of my matches were so old that they were almost irrelevant.

A GD of [email protected] markers seems rather reasonable to me, and with more markers tested the wider the genetic distance limits, 37 markers should be the minimum level of markers people have tested with 67 and 111 being even better still.

[Ric]

The point is to allow for whatever matches you may get to be more relevant than the ones older than 4300 years. I'm not sure I'd be a happy customer if the majority of my matches were so old that they were almost irrelevant.

Yes I know, but it doesn't work with customers who have a GD of 5 or more on a single STR, compared to the mode for that particular STR (the mode in their terminal SNP subgroup or nearby subgroups for that STR, these values are called off modal in the groups).

A GD of [email protected] markers seems rather reasonable to me, and with more markers tested the wider the genetic distance limits, 37 markers should be the minimum level of markers people have tested with 67 and 111 being even better still.

From a Molecular biology point of view, a lot of slightly different mechanisms could be responsible for slightly different results. The DNA polymerase complex that replicates DNA has many subunits, some dedicated to 'proof-reading', some dedicated to other tasks during replication. DNA replication is a complex chemical process. A +1 repeat addition or subtraction to a short tandem repeat could result from a 'normal' proof reading mistake, while a brutal 7 (or more) addition or subtraction from the normal value (again : 'normal' = the Mode) on a single particular STR could result from a slippage of the DNA-Pol on that particular STR, which results in the dreaded off modal value. In short, different mechanisms demand different interpretations of these results, which implies that, NO, GD=2 for 25 STR is not necessarily acceptable for everybody. Even if it works in 90% cases, it is disrespectful to ignore the other 10% that have nonetheless paid the same amount of money for the test.
Many STR customers who have killer off modal value on one single STR have ZERO Matches, depending on where is positioned that STR (the first 12, the first 25... etc. ) and depending on when the mutation occurred, and they are not happy with that. A simple fix would be to relax the GD threshold to accommodate these killer GD. I'd prefer the option to input manually the 'mode' on a particular STR, but I'd take whatever comes.
A few months ago, there was a bug in the STR match list that allowed to retrieve matches up to the maximum GD of your test (for example GD= 7 if you tested STR67)for ALL your matches. That means that you could see your 25 matches up to GD=7 if you had tested STR67!
That bug was actually an improvement over the current algorithm, at least for those with off modal values who suddenly saw matches popping up at GD deemed 'irrelevant' in a normal situation.
In my personal case, I have 4000+ STR 11/12 and 12/12 (irrelevant) matches, spread all over the world, from Australia to Siberia, but I have a few severe off modal values after the first 12. So, no surprise, I have zero match at 25 and above. When the 'bug' occurred, I was able to retrieve a 22/25 STR match, so a GD=3 for 25 which is normally disqualifying and does not appear, and guess what, the match was the closest match geographically, 40 miles away from my paternal ancestor location on the map ! among 4000+ others. And the same applied for GD=4 and 5 for 25-level STRs, all were nearby the relevant area!
Clearly, there was geographical information embedded in the GD=3, 4 and 5 of my STR25 matches, and that's all I want for my $300 spent for that test.

[Ric]

I digressed but coming back to the BigY matches, i will quote Stalin again : 'Quantity is a quality by itself'.
So if you have a few BigY matches at GD=40 (40SNP difference) and nothing else, but all from the same area, you may perhaps infer that a possible and more significant match at GD=30 lives in that area. If you have no matches at all, you can't infer anything.

[ksaha1]

Another Zero match Big-Y User

I agree entirely as I have gone from over one hundred to Zero so don't see any use in the Big-Y data to the average user.

I wish I could still get access to my previous matches just to give me something to think about as a blank set just telly me nothing. Poor show Big-Y.

[The_Contemplator]

I have a Big Y with no matches, even BEFORE the October update. So welcome to the club. Then again my STR test has no matches at any level either. Something I expected with the Big Y given my STR results. But I went with it so that future potential matches can find me. Instead of being upset at it, I focused on other branches. An uncle's Y line has been of more interest than my own so far.

You could also just go recruit. Find people with paternal lines from the region yours came from. Or test a known cousin (or a distant cousin) to see if they have better STR results that will yield the matches that are just barely out of reach from your own results. You can also just go to the haplogroup project and try to contact others of your own branch. Those matches that are no longer matches now may be interested in sharing the data you seek.

[Wheal]

My father has zero matches on Big Y but 3 matches @7 on Y-67... since he is in a haplogroup all of his own, it is somewhat frustrating.

[Conat]

I have 14 matches. As you can see in the attachment that breaks down to 8 R-L151 and 6 R-P312, so far back in time that they are of no use to me. Meanwhile, the 4 people in R-BY3483 with me have disappeared. Luckily I was able to get their details and contact them first so we could compare results, but I won't see any new matches unless, apparently, they are already Y-STR matches:

A threshold of 30 non-matching variants (SNPs) has been added to the matching algorithm. If you have more than that limit with anyone then they won't show as a BigY match. That means that all of your BigY matches that disappeared do not share a common ancestor with you in the direct paternal line further back in time than your current BigY matches. Your BigY matches that aren't Y67 or Y111 matches, if you and they had those tests, are unlikely to have a common ancestor with you in the direct paternal line in a genealogical time period.

The problem is that I and another R-BY3483er did SNP testing because neither of our Y-STR results are very useful (they don't vary much from the hypothesised ancestral states so we have a large number of low quality results). Now granted R-BY3483 is around 2,800 years old:

http://www.ytree.net/DisplayTree.php?blockID=2065

But the information we got from it was useful and we were able to compare notes with the others in the group some of whom have very good Y-STR results (large divergence from the "background" so they have a low number of good quality results, all of whom are presumably going to be somewhere on their branch) and we've been able to tease out the start of an idea of how our paternal lines got to where they ended up. This is only possible because of the combination of Y-STR and SNP results in their case.

As this seems to be a feature not a bug, I don't feel I can really recommend the Big Y to anyone as I don't see it adding much extra information that you can't get from Y-STR. If I'd spent all the money, taken the test and been faced with no results in the last 3-4,000 years I'd have probably jacked the whole genetic genealogy business in right there. Instead I've got a few clues, met a group of over a dozen men in my haplogroup and will probably start a R-BY3483 group to help gather them together and seeing if more of the Y-STR matches the others have would be interested in taking the Big Y, which benefits FTDNA in the long run.