eLife assessment
Maestri et al report the absence of phylogenetic evidence supporting codiversification of mammalian coronaviruses and their hosts, leading to the important conclusion that the evolutionary history of the virus and its hosts are decoupled through frequent host switches. The evidence for frequent host switching, derived from a probabilistic model of co-evolution, appears convincing, but evidence for quantitative statements about the time of the last common ancestor of extant mammalian coronaviruses remains incomplete. The results would be strengthened by a reconstruction of the evolutionary timescale and further investigation of robustness to sampling biases and unsampled diversity.