Some of my recent posts have included explorations based on DNA matching. This has been based on longstanding “STR” y-chromosome markers, and I think it’s led to some interesting insights, including those I’ve written up in this blog.
There’s another major type of y-chromosome analysis, “SNPs” — look up the difference online as it’s too complex for me to attempt. Basically, the STRs are easy to find, and the SNPs are more about the structure of the DNA and potentially a more precise way to distinguish between lines. They are however a less mature technology.
To be a real match, you need to be close on both STRs and SNPs. The premise of this analysis is that STR markers tend to mutate in particular patterns, and even people with quite different SNPs can end up with similar STRs (“convergence”). I struggle with that, because even with 37 markers the patterns for different families look really different, so I have assumed that when they do all match with particular patterns the people must be closely related, but apparently it’s not that simple. (Never is…)
Recently, the DNA testing community has been developing focus groups based on ever more divisions of the old haplogroups. As each subgroup gets better understood and recruits more members, it becomes unwieldy and spawns new subgroups.
Even last year, SNP analysis was mostly about the prehistoric movements of peoples. We are just starting to get DNA results from archaeological finds, and my subgroup has its earliest links around Sweden/Denmark/Frisia. This research is still moving quickly and it’s very interesting to watch.
The subgroup has about 300 people in it, and it’s very active right now. We are starting to get to the fidelity where we can answer questions in genealogical times, ie the last 500 or so years. Some of the names I’ve mentioned in this blog are apparently closely related to each other as I’ve suggested: Burton, England, Shelton — I don’t think they have a Harwood tester in this group alas.
However, the current tree as drawn up has me a little further away. Oversimplifying greatly, the present state of analysis says I’m 1500 years away from a common ancestor, and I think I should be just 500 years away. It’s not just one marker, it’s several, so the local expert thinks it’s very unlikely to be random mutations or automated transcription errors. SNP testing is very complex, and I don’t know what the rates of false positives and negatives are.
I have done the very latest DNA test, for 700 SNP markers, and so are many of the testers in my subgroup. As more people do this level of testing, I expect the relationships will become clearer.
A H*wet Hub 