Where next for DNA? A Roadmap in Light of Developments

This post is prompted by 3 recent developments. Firstly FamilyTreeDNA have announced a summer sale lasting the whole of August. Significant amongst the reductions is the Big Y test is being offered at $395. I plan to take advantage of this to fund another test within the Cheshire group.

The significance of Big Y tests, and similar Next Generation Sequencing (NGS) tests is two-fold. It is the mapmaker that extends Y-chromosome genetic tree closer to modern times, and it positions you and your clan precisely on that map so you can understand  the historic path your Y-chromosome travelled from the time it left Africa 75,000 year ago.

The second development was an article in a digital newsletter I get from the Lost Cousins website, which as the title implies, aims to help you find cousins. Although a member I have done very little with it so far. The article stated that 90% of DNA tests ordered these days are autosomal tests. In fact Ancestry only offer autosomal tests. The FamilyTreeDNA offering, the Family Finder test, is $69 in the current sale.

Autosomal tests look at the whole of your genome, not just the male or female lines, and tell you in percentage terms the origins of your DNA. For example I am 89% British Isles, and 4% Western European, with traces from the Near East and Africa. When I first tested with the National Geographic Project I was also 2% Neanderthal. Perhaps more importantly the test help you find cousins, and so have a natural fit with the Lost Cousins website. Through matching websites such as GEDMATCH you can compare your result with large numbers of others to find potential cousins, back to about your 5th cousins.

The attraction of autosomal tests is they are relatively cheap, and they cover all your ancestors. However they are only useful for the last 5 or so generations. Y-chromosome testing is confined to the male line, which is a good fit for a One-Name Study. The Y-chromosome is unique (along with mitochondria) in that is passed virtually unchanged from generation to generation so you can uncover its history from very early times.

It also occurs to me  that we can follow many such lines into out ancient history. Whenever you find a male cousin who shares a surname with one of your male ancestors  he almost certainly also carries his Y-chromosome. The history of that Y-chromosome is the history of one of your ancestors, so if your new cousin has discovered it so can you. The same is true of any cousin descended in the female line from one of your female ancestors. They will share her mitochondria and its associated history. The interest in finding cousins therefore has a nice synergy with Y-chromosome and mitochondrial testing.

The third development behind this post is an article in the July-Sept 2017 issue of the Journal of One-Name Studies by Charles Acree on Advanced Y-DNA Testing for the Acree One-Name Study. It discussed how Single Nucleotide Polymorphism (SNP) testing can produce better results more cheaply than the Series Tandem Repeat (STR) tests that One-Name Studies have used so far.  It mirrored ideas I have posted on here in the past and made me think I should do a similar article on the Warburtons. However I think the Warburtons are a larger and more diverse group, and the requirements will be slightly different.

The idea is that SNP testing can be more accurate, and cheaper than STR testing. A single SNP can be tested for $18 at YSEQ, whilst I have set up a panel of 7 SNPs relevant to the Lancashire group for $103. The standard 37 marker STR test at FamilyTreeDNA used by the Warburton project is $149. The problem is knowing which of the many thousands (maybe millions) of known SNPs to test for.

There are just a couple of SNPs that would tell if you are a member of the Lancashire clan, and a couple of others that would indicate membership of the Cheshire clan. But I don’t yet know suitable SNPs for the many other Warburton results I have. This is where the Big Y test comes in, to map out the area to look at.

The value of the STR test is that it gets some way to putting you in the correct area. It would identify whether you were a probable member of the Lancashire or Cheshire groups, or a match to another Warburton result. The question is whether a 37 marker test is necessary or fewer markers would suffice.  I have experimented a couple of times with a 12 marker test at FamilyTreeDNA with some success. However I have now discovered that YSEQ have an Alpha Panel of 18 markers for $58 which would be a better bet. In fact YSEQ have a number of STR panels which look a lot cheaper than FamilyTreeDNA. However their NGS test is more expensive, but more comprehensive, than Big Y.

So based on the above my suggested roadmap for someone contemplating Y-chromosome testing is:

  1. Check whether there are already DNA results for someone with whom you share a Warburton male ancestor. In the absence of a non-pateral event (NPE) you will share his results, but might want to encourage him to move along the roadmap.
  2. If there are no existing results, or there is the possibility of an NPE, take the YSEQ STR Alpha Panel and send me the results so I can see if there are some likely matches.
  3. If you match with someone where recent SNPs have been established, test one or more SNPs to find where you fit. In the future more SNPs may be discovered which you could test for if the result would add further meaning.
  4. If you don’t have a match, or your matches haven’t explored their SNPs ,it may be necessary to test a SNP panel of 7 or more SNPs to home in on the area where you fit.
  5. In some cases it might be appropriate for you or one of your matches to take a Next Generation Sequencing Test (such as Big Y) to extend the SNP map in the area where you fit.

 

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