Y DNA. Which test? How far back?

Question

I could be wrong about how the Y-DNA tests work, but of the tests available which test for different numbers of markers, the 37, the 67, the 111, and the 700, how many years back can you expect to get results for each test? Or, which test would be recommended if you are trying to match results 400 - 500 years back, and 1000 - 1200 years back? If this isn't how it works, feel free to explain. Thank you.

Comments

Not DNA but this might be some help with the early generations of Molesworth. John Molesworth, born about 1490, was of Helpeston, Nhants. Here is a Thomas Molesworth/Mollesworth/Mullesworth of Helpeston in the court of Common Pleas in the 1470s.

In 1472:
Nhants. William Crowelond versus Thomas Mullesworth, of Helpeston, (Nhants), gentleman, and Thomas Kynge, of Helpeston, yeoman, for trespass: assault at Helpeston

http://aalt.law.uh.edu/AALT2/E4/CP40no841/bCP40no841dorses/IMG_1671.htm

In 1475:
London. Richard Crakenthorp, of London, tailor, versus Thomas Mollesworth, of London, or of Helpston, Lincs, (Nhants?) gentleman, for a debt of 40 shillings.
http://aalt.law.uh.edu/AALT2/E4/CP40no853/bCP40no853dorses/IMG_1715.htm

In this second one it says Lincolnshire, but there is no Helpston there so I think it must be an error. 

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Thank you. I don't think I've seen those before, because of the misspelling. But it is definitely the correct locations. I'll have to find how it fits in.

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I think I'm am finally understanding, after reading several of the answers, and trying to get my head around it for a couple of days. You can match up to a greater or lesser degree with 37 markers, but that won't indicate how close you are, if you test for more markers. If you then test for 67 markers, you could discover that all of the extra markers match, or none of them. Likewise getting 111 markers testing. So 111 will give a more accurate list of matches, but 37 will give a larger list of matches, but less accurate. The more markers, the less, but more matches. If anything, 37 markers will be more accurate for a distant back in time, and the more markers should make more recent matches more reliable, but also those further back. These are all different markers to those tested in the Big Y test. So taking both the 111 marker test, and Big Y, would possibly even give better indication of matches, but I may or may not be right on that.

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I would not say 37 markers is more accurate at all, it's a limited dataset compared to the 111 or BigY700. It's like a filter. If you have a lower grade filter, more stuff gets through, but if you up the density of the filter, you only let smaller things through.

Matches at 37 markers could be unrelated people, it's a false positive. You can sort that out the higher number of markers you test.

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Not saying that 37 markers is more accurate than 111. But that 37 markers would more accurately represent a further time period, than a closer one, because it is showing more of a scattered result. I probably should have found a word other than accurate, as mentioned in an answer below.

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Hi Ben,  When advising folks on YDNA tests, I always say start with YDNA37 marker test.  FTDNA will store your test for 25 years, so you can always update later to add more markers if desired.

I am interested in family history that can be documented.  That narrows my search mostly to post-1600 years and I find that 37 markers is sufficient to point to which paternal line of forefathers is yours.  There is only one Molesworth test on FTDNA (https://www.familytreedna.com/group-project-search?sType=eq&search=Molesworth), so I think it is not useful to spend a lot of money on a high count YDNA test when you probably won't have any paternal line matches.  I say start with YDNA37.  They are on sale now, I think.

Answer 1

Hi Ben,

Y-DNA is exclusively for the direct male line - father to son, father to son (Patrilineal)  So in your case, it will be the Molesworth surname direct line. Your father and his father etc etc.

It can be accurate 'up to' 10 generations (assuming 25-30 years per generation)

Because a man has a single copy of the Y chromosome, that copy is passed onto his sons without recombination. There can be occasional mutations, however the Y chromosome remains essentially identical. This can help with deep diving into paternal lineage because it's not recombined with every generation.

It 'may' identify a family of interest but as we have found out so far using my brother's Y DNA -  not identify specific members of that family.

A Y-DNA test may: 

• Match other men with expected Surname
• Match with men with unexpected Surname (surname may have changed slightly over generations?)
• Several Surname groups (multiple matches with each surname: big Y-700 may determine which surname is most closely related to the original tester)
• N matches with N surnames = No surname pattern in all his matches
• No matches

Desirable outcome is obviously the first - matches with an expected Surname

The Markers - there are hundreds of them: Y-DNA testing  from 10-111 STR markers on the Y Chromosome. STR markers provide the Haplotype and SNP marker provide the Haplogroup.

The more markers that are tested, the more information and probability. 

Example: if two people match perfectly on 37 Markers, there is a 50% probability that the MRCA (Most recent common Ancestor) is fewer than 2 - 3 generations ago. A 90% probability that the MRCA is fewer than 5 generations and 95% probability the MRCA is fewer that 7 generations.

Hope that helps a little, I'm sure others will have more info.

Cousin Keryn

Comments

Thank you Keryn. I understand some of it, and some of it I don't. I understand that it is passed on from to Male to Male, and that there is a consistent amount of loss of information every generation, giving an ability to connect with males who should have the same surname. My greatest chance of connecting with someone, is if I can demonstrate that my line is accurate back to Viscount Molesworth, 10 generations back. It also gives a good broad opportunity at that point, because the paper work of the tree is fairly complete from the Viscount down today, across all the branches. I also though, have a point, another 10 or more generations further back, in which there is a debate about the origin of Molesworth's, coming from the Lindsay clan. Some of the Lindsay's deny our connection, while some accept our connection. But if a test could prove, and given there aren't mistakes in my line, that we descend from the Lindsay's. So 10 generations is 400 years, and about 24 generations is 1000 years.

What I don't understand, is the functionality of how the testing and results work. But hopefully that clarifies, that it is my paternal line that I am trying to seek some answers on. I will use the general DNA test to do the broad spectrum of 4 generations across my tree. Hopefully those tests will help with the Keane puzzle somewhat.

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So I guess, what I'm wanting to know, is what is the accuracy, or possibility of the 37, or 67, or 111, or Big-Y, for the 10 generations, and for the 24 generations.

The example you gave, gives less probability the closer they are to you. I'm not sure that that made sense to me. I guess it is because the test isn't a complete test of all the markers.

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You want either whole genome sequencing or the bigY to prove your branch. Matches at lower levels turn out to not be matches at higher levels, and more info is much more helpful there. Are there already testers for the Viscounts descendants on different branches?

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There aren't any on Wikitree. There is at least one for the Lindsay's further back. I do know one person though, with the surname Molesworth, who can't find his connection into the tree, and is pretty desperate to get a connection.

Of course, the whole lot always depends on the accuracy of whether the tree was true or not too. The further you go back, the more chance that someone had an affair.

Answer 2

I agree Ben

This is where the point of difference lies with the Molesworth side and proving the Viscount connection where the split may have occurred or there was a name change or you have the ''matches with unexpected Surname"

Obviously the more expensive Y-DNA test will do more markers - chances increase I guess in getting a decent result (as long as the other trees are accurate)

Kez

Answer 3

Looking  at the surname projects at FTDNA, I see the Mould surname project, which also covers variations of the name including Moldsworth. I would request to join the Mould project and start with a 37-marker Y-DNA test. See who your closest matches are. Then, decide what your next step is from there.

Comments

You might also consider the Lindsey/Lindsay Project to join. Once you have taken a test, you can join more than one. And I would recommend taking the best Y-DNA test level you can afford. Depending on the Haplogroup you are in, this could still be several thousand years back.  The higher the number of markers tested.... the more recent the possibilities.

Ken

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Thank you. I'll have to do this. Hopefully all my paternal line had honest wives, and I might be able to provide a clear line back.

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Good luck! FTDNA usually has a holiday sale. Have fun. It's a new adventure!

Answer 4

Ben, I think there's a more appropriate way of looking at Y-DNA test results than in terms of matches.  What your Y-DNA test tells you is what genetic markers you have (and don't have) in your Y chromosome, and which other Y-DNA testers have these same markers.  If two men share the same markers, they share certain direct male ancestors.  They are related, either closely or distantly, depending on which and how many markers are shared.  You could say that they're close or distant "matches," but I think the concept of close or distant relatives is more useful.  We're all related - it's just a matter of how closely.

There's a huge difference between the results from Y-STR type tests (such as Y-37, Y-67 and Y-111 from FamilyTreeDNA) and a Y-SNP test (such as FTDNA's Big Y).  The reason for this is that STRs and SNPs are two very different types of genetic markers, and they provide different information.  In my opinion, the most important and useful test (by far) is the SNP-based test.  The only real benefit of taking a STR test (again, in my opinion) is to receive, at a relatively low cost, the "predicted" haplogroup it provides (sometimes referred to as a haplotype), which tells you what ancient (thousands of years in the past) genetic grouping you belong to - and, sometimes just as useful, rules out which ancient groups you're NOT connected to.  Any of the STR tests provide this predicted group, so you may as well take the cheapest one.

Essentially, SNPs are the mutations in the Y chromosome which have formed over time - a chronological sequence of mutations - and once they're there, they (almost) never change.  A SNP test (such as Big Y) measures every genetically useful SNP in your Y chromosome, which allows a direct comparison with every other (Big Y) tester's SNPs.  So determining a connection between two Y-DNA testers using a SNP test is really very simple: the longer the sequence of shared SNPs between them, the more closely they are related.  Conversely, the shorter the shared sequence, the more distantly related they are, or stated another way, the further back in time their lines branched off from one another.

There are some subtleties in working out exact relationships between relatively closely related men (closer than, say 10th cousins), corresponding to just which cousins would need to be tested, but this is entirely possible through SNP testing.

I hope this answers your question.

Comments

Thank you Robert. I have been sitting and pondering the answer for a couple of days, and just reading back over your answer, really makes a lot of sense now. Thank you. It becomes surprisingly complicated, when you begin off, thinking about it the wrong way.

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Thanks Ben - it's not uncomplicated even when you start out thinking about it in (more or less) the right way!  It took me ages to comprehend just how Y-DNA works, at a level, and from a point of view, that I was comfortable with.  (There are a LOT of details about the science and analytical process that I'm still working to understand!)  If you recognize that what the SNP test (BigY) gives you is your own personal chronological sequence of SNPs, and that comparison of this sequence with that of other testers is the basis for determining your level of relatedness, you're off to a great start.  I highly recommend the book "The Genealogist's Guide to Y-DNA Testing for Genetic Genealogy," by David Vance, as an excellent introduction to the field, as well as for more advanced topics.

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Thank you Robert.

Answer 5

A yDNA test is only going help you if you have matches with men who also have documented trees back to a shared common ancestor, however far back that happens to be. If cost is not an issue, you may want to take a Big Y-700 test. But if you're concerned about cost, you could start with a 37-marker yDNA test, to see if you have any matches named Molesworth (or variations). If you do have matches, depending on the level that your match(es) have tested, you could upgrade your test to a comparable level.

Comments

Likewise, thank you Kay. This makes more sense now. I wasn't thinking about it the right way, and it certainly confused the issue.

Answer 6

The term "Accuracy" has little meaning relative to a y-DNA test. Testing the same person ten times will almost certainly yield exactly the same result and are therefore accurate. The terms Y-37, Y-67, etc. refers to the number of STR's which can be compared to other test takers. Statistical inferences can be made from the number of matching STRs between users. Larger numbers of STRs increase the Statistical Confidence Level, but not the Accuracy.

Testing more STRs with fewer differences, will statistically estimate a closer genetic distance (in generations.) For example, many men often have 12 identical STR markers (Y-12) without being closely related. By contrast, men sharing all 111 STR markers (Y-111) would probably be closely related within a few generations, regardless of surname. Individual STRs even have statistically different rates of mutation, which can also be taken in to account. All estimates of generational distances are based upon statistical analysis. With a sufficient number of matches, STR results be used to trace back maybe 1,000 years.

SNPs (or Haplogroup) can also be found from y-DNA testing. SNP mutations can be reliably traced back for thousands of years, back to origins of all humans in Africa. You can discover details about locations and ages of SNP mutations without having any STR matches. The Big-Y DNA test will provide the most refined SNP (Haplogroup) result for you (as well as the largest number of STRs tested.) SNP results will trace back before surnames came into common use.

To visualize some SNP results, I recommend using the website SNP Tracker and selecting an Example in the menu there. More specific SNPs will result in more detailed tracking results. (For example mine is I-FTA19401).

A comparison of STR and SNP results and their inferences is provided by following graph, which I think may explain it best:

Comments

Thank you Bill. I've been watching a series by Nathaniel Jeanson, from his book called Traced, which uses the very consistent loss of Y-Dna detail, in a whole world tree, similar to the example in your picture, where they are able to pin point historic migrations of people, based on the change of Y-Dna. For example, when the Mongols attacked through into Europe. It is very interesting research. It certainly confuses the whole concept of the STR tests. I think I managed to get my head around it now though, having previously thought, that if the Big Y test, shows historically back to the union of all mankind, that smaller tests would provide only more recent history, was it turned out, not the correct way to view the tests. Thank you for your explanation too. It is hard to tell who did the better job, because all of the answers have helped me to finally clear up my misunderstanding.

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And the good thing too Ben, is that if you save up for the Big-Y test at FTDNA (usually a great sale on Black Friday). as more and more folks test in the future, your terminal SNP will probably change (and become more recent). In 2018, I started out as I-Z138/S296 with a Time to Most Recent Common Ancestor (TMRCA)  of about 4500 Years before Present (YBP) with the STR tests results.  Once the Big Y SNP results processed, this was moved down to I-S19185 with a tmrca of about 3800 ybp.  Again, this was all in 2018.  Since then, more and more people have tested and I am now five steps beyond that at I-Y94629, with a TMRCA of about 1800 YBP. This doesn't really happen much with just an STR type test (Y-37, Y-111), and I would have just stayed at the much older I-Z138.

I am not a DNA expert by any means, but this is the WHY I spent the extra $$$ on a higher level test!

Hope this helps....

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Yes. It certainly does. I will wait for the sale. I need to get in when it is more affordable.

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FTDNA is having an "Early Bird" sale now, going through about the next 3 weeks - it's one of their better ones (deeper discounts).

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Thank you Bill for this excellent diagram by ‘Tiger’ Mike Walsh. He has done several such diagrams but this one is really helpful to answer the ‘which test’ question. My experience is to do Y-37 first to find matching ‘like surnames’ then encourage deeper BigY testing. This gives much clearer definition of the haplogroup relationships.

I’m less sure that STR testing is better for close relatives as it did not agree with proved paper trail and BigY matches in my tree.