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View Full Version : need help making sense of isogg subclade nomenclature



NewAlbion
06-13-2017, 09:08 AM
I hope this is in the right forum . The deepest I can trace my Y-DNA via the ISOGG tree is :


R1b1a1a2a1a2c1f3~ FGC496.1/Z6749.1, FGC5561, S2202

My question is if everything after the tilde are nomenclature synonyms or represent, after each comma, another deeper subclade (sorry, if my terminology is wrong) ?


Also, would these or it be found more likely in Ireland or Britain ?

Wing Genealogist
06-13-2017, 09:38 AM
When a "/" is used (FGC496.1/Z6749.1) it indicates the two names are for the same SNP mutation. FGC indicates it was named by Full Genomes Corporation (either through one of their NGS/FGS tests or through their analysis of a Big Y file). Z typically indicates it was named by one of many "citizen scientists" (originally through analyzing data from the 1000 genomes project, but it has expanded to other projects as well).

When a "," is used (FGC5561, S2202) it indicates the two SNP mutations are actually different mutations, but they are currently equivalent SNPs.

Currently equivalent SNPs mean that everyone thus far who has been tested for both of those SNPs are either positive for both SNPs or negative for both SNPs. It is possible at some future time someone will test positive for one equivalent SNP and negative for another, then we can split up the clade and further refine the tree.

While it is certainly possible for two (or even more) Y-SNP mutations to occur in a single father-son transmission, many more equivalent SNPs actually happened at different generations.

It is likely some in some cases, there are no living individuals (or fossil remains) who exist to split up some of the currently equivalent SNPs (in which case they would forever remain equivalent).

NGS/FGS - Next Generation Sequence/Full Genome Sequence. They use a newer technology than the traditional Sanger Sequence to read the data. NGS tests are limited to the Y Chromosome and include FTDNA's Big Y test and Full Genomes Y-Elite test. FGS test all of the DNA (and usually include the mtDNA as well). Last I knew, Gene by Gene (the parent company of FTDNA) offered an FGS test (at an incredibly high price). Full Genomes offers a variety of FGS tests and YSEQ currently offers a 30x FGS test.

TigerMW
06-13-2017, 04:45 PM
I hope this is in the right forum . The deepest I can trace my Y-DNA via the ISOGG tree is :


R1b1a1a2a1a2c1f3~ FGC496.1/Z6749.1, FGC5561, S2202

My question is if everything after the tilde are nomenclature synonyms or represent, after each comma, another deeper subclade (sorry, if my terminology is wrong) ?


Also, would these or it be found more likely in Ireland or Britain ?

The tilde (~) represents approximate so there are probably some SNPs in brother subclades not tested for this branch or perhaps there is some other uncertainty.