Evolution: Genomic pacemakers or ticking clocks?

Although different genes evolve at different rates, when complete sets of orthologous genes are considered across taxa, the distribution of rates is remarkably conserved. That is, the differences in the rates of evolution among genes in a genome remain consistent. A potential explanation for this observation is the molecular clock, which is a model that has been used widely in phylogenetics. Now, Koonin and colleagues show that available phylogenetic data are more compatible with an alternative model that they propose termed the universal pacemaker (UPM).

Nature Reviews Genetics, Published online 18 December 2012 | doi:10.1038/nrg3410

Snir S, Wolf YI, Koonin EV.
PLoS Comput Biol. 

2012 Nov;8(11):e1002785. doi: 10.1371/journal.pcbi.1002785