@article {Hamilton020933, author = {David Hamilton}, title = {An accurate genetic clock}, elocation-id = {020933}, year = {2015}, doi = {10.1101/020933}, publisher = {Cold Spring Harbor Laboratory}, abstract = {Our method for {\textquotedblleft}Time to most recent common ancestor{\textquotedblright} TMRCA of genetic trees for the first time deals with natural selection by apriori mathematics and not as a random factor. Bioprocesses such as {\textquotedblleft}kin selection{\textquotedblright} generate a few overrepresented {\textquotedblleft}singular lineages{\textquotedblright} 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 {\textquotedblleft}reduction{\textquotedblright} 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 {\textquotedblleft}pedigree{\textquotedblright} (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 P{\"a}{\"a}bo et al, together proving R1a1a \& R1b1a2 originates in the Russian Steppes.}, URL = {https://www.biorxiv.org/content/early/2015/06/19/020933}, eprint = {https://www.biorxiv.org/content/early/2015/06/19/020933.full.pdf}, journal = {bioRxiv} }