Polyphyletic relationships in Sorghum

Sorghum is an essential grain crop whose evolutionary placement within the Andropogoneae has been the subject of scrutiny for decades. Hawkins et al. explore the generic limits of Sorghum and its placement within the larger Andropogoneae using two phylogenetic reconstruction methods and incorporating a large number of diverse genera. The results provide compelling evidence for a two-lineage polyphyletic ancestry of Sorghum within the larger Andropogoneae, i.e. the derivation of the two major Sorghum clades from a unique common ancestor. They conclude that previous studies suggesting monophyly may have been the result of limited taxon sampling outside of the genus.