RT Journal Article SR Electronic T1 An accurate genetic clock JF bioRxiv FD Cold Spring Harbor Laboratory SP 020933 DO 10.1101/020933 A1 David Hamilton YR 2015 UL http://biorxiv.org/content/early/2015/06/15/020933.abstract AB Our method for “Time to most recent common ancestor” TMRCA of genetic trees for the first time deals with natural selection by apriori mathematics and not as a random factor. Bioprocesses such as “kin selection” generate a few overrepresented “singular lineages” while almost all other lineages terminate. This non-uniform branching gives greatly exaggerated TMRCA with current methods. Thus we introduce an inhomogenous stochastic process which will detect singular lineages by asymmetries, whose “reduction” then gives true TMRCA. Reduction implies younger TMRCA, with smaller errors. This gives a new phylogenetic method for computing mutation rates, with results similar to “pedigree” (meiosis) data. Despite these low rates, reduction implies younger TMRCA, with smaller errors. We establish accuracy by a comparison across a wide range of time, indeed this is only y-clock giving consistent results for 500-15,000 ybp. In particular we show that the dominant European y-haplotypes R1a1a & R1b1a2, expand from c3700BC, not reaching Anatolia before c3300BC. This contradicts current clocks dating R1b1a2 to either the Neolithic Near East or Paleo-Europe. However our dates match R1a1a & R1b1a2 found in Yamnaya cemetaries of c3300BC by Svante Pääbo et al, together proving R1a1a & R1b1a2 originates in the Russian Steppes.