Resumen
- In their report of the genome sequence and assembly of Tibetan wild boar, Li et al.1 dated the divergence between Tibetan wild boar and Duroc pig to 6.9 million years ago (bounds of 3.4–12.9 million years ago) using a list of 1,141 orthologous genes for pig, cattle, dog and human. This divergence time is unlikely and even predates the currently accepted time for suid speciation2. If the divergence times estimated by Li et al. were correct, it would mean that Tibetan wild boars would have constituted a separate clade that colonized Tibet far earlier than Sus scrofa migrated through Eurasia around 1.2 million years ago. However, the same authors also report that “Tibetan wild boars and Chinese domestic pigs are genetically indistinguishable at an overall genomic level” (on the basis of the principal-component analysis in Fig. 2d of ref. 1).