Phylogenomics, Lineage Diversification Rates, and the Evolution of Diadromy in Clupeiformes (Anchovies, Herrings, Sardines, and Relatives).

The article focuses on the evolutionary history and diversification patterns of diadromy—the migration between marine and freshwater environments—in Clupeiformes, a diverse clade of fishes including herrings, sardines, shads, and anchovies. Using a comprehensive phylogenomic dataset and advanced phylogenetic methods, the study identified 13 independent origins of diadromy during the Cenozoic Era and documented multiple losses of this trait, indicating that diadromy is not an evolutionary dead end. While one diadromous clade (Alosa) exhibited significantly elevated lineage diversification rates, overall there was little consistent statistical support for faster diversification in diadromous versus nondiadromous clupeiforms, suggesting that the influence of diadromy on diversification is context-dependent and modulated by factors such as migration distance and biogeographic setting. The study also clarified major phylogenetic relationships within Clupeiformes and provided updated divergence time estimates, supporting a Late Triassic/Early Jurassic origin of crown Clupeiformes.