Y-DNA Analysis‎ > ‎

Using Phylogenetic Trees

This website posts Fitch and Kitsch phylogenetic trees, generated using the Fitch and Kitsch applications from the Phylogeny Inference Package (“PHYLIP”) suite of genetic programs, that show, in tree format, inferred relationships among R1a1a Ashkenazi Levites. Those applications place R1a1a Ashkenazi Levites on trees based upon each man's distance, in years, to an MRCA with each other man. 

The trees are generated from the information in the Y Utility spreadsheet, discussed here, using STR values to calculate the number of years to an MRCA among each R1a1a Ashkenazi Levite, based upon: (1) a 50% likelihood of time to an MRCA; and (2) FTDNA mutation rates.

Generally speaking, men who are most closely related to each other should be grouped closely on the trees. Because of independent mutations and back-mutations, there will be some inaccuracies in the trees. Because SNPs do not back-mutate without the back-mutations being obvious, trees based upon SNPs should be more accurate than trees based upon STRs (once enough men have tested SNPs to allow construction of an SNP tree for R1a1a Ashkenazi Levites). In turn, it should be possible to tie SNPs to patterns of STR marker values for the purpose of placing on a tree men who have not had their Y-DNA SNPs tested.
Nathan Saevitz & Family

Nathan Saevitz (b. Romny, Ukraine, @1879; d. London 1934) with
his wife Rebecca (Bessie) nee Troshanski and their sons (left to
right) Louis, Joseph, Barnett (Ben) and Herschel (Harry)
Photograph taken in London in @1910