PT - JOURNAL ARTICLE AU - D. H. Hamilton TI - AN ACCURATE GENETIC CLOCK AID - 10.1101/019414 DP - 2015 Jan 01 TA - bioRxiv PG - 019414 4099 - http://biorxiv.org/content/early/2015/05/20/019414.short 4100 - http://biorxiv.org/content/early/2015/05/20/019414.full AB - Molecular clocks give “Time to most recent common ancestor” TMRCA of genetic trees. By Watson-Galton17 most lineages terminate, with a few overrepresented singular lineages generated by W. Hamilton’s “kin selection”13. Applying current methods to this non-uniform branching produces greatly exaggerated TMRCA. We introduce an inhomogenous stochastic process which detects singular lineages by asymmetries, whose reduction gives true TMRCA. This implies a new method for computing mutation rates. Despite low rates similar to mitosis data, reduction implies younger TMRCA, with smaller errors. We establish accuracy by a comparison across a wide range of time, indeed this is only clock giving consistent results for both short and long term times. In particular we show that the dominant European y-haplotypes R1a1a & R1b1a2, expand from c3700BC, not reaching Anatolia before c3300BC. While this contradicts current clocks which date R1b1a2 to either the Neolithic Near East4 or Paleo-Europe20, our dates support recent genetic analysis of ancient skeletons by Reich23.