This can allow Y-DNA test takers to discover which branch of a family or clan they descend from and thus greatly enhance their genealogical research.
Statistically based calculations can provide estimates of dates of formation, but our research aims to reach conclusions founded on DNA and documentary evidence.
With such extensive sequencing, mutations that have occurred between generations can now be identified. A mutation on the Y-chromosome within the portions sequenced by the Big Y is calculated to occur on average every 83 years, based on data from the YDNA Warehouse.
It is often the case that the number of generations within which a SNP must have been formed can be refined, as further tests reveal new positive and negative results, splitting up the blocks of SNPs at branching points, thus allowing what we have termed multi-generational SNP dating.
Moving beyond this stage, if certain strict criteria are met it is possible to identify SNP progenitors. Present day test takers with well documented descents allow us to identify named people as SNP progenitors , individuals who lived in the past and in whom specific SNPs can be shown to have been formed. This can be done by evaluating test results from multiple surviving male lines of a family. This can be confirmed if tests on male line descendants of two or more of his sons are found to be positive for the SNP and tests of male line descendants of at least one of his brothers are found to be negative for the SNP.
