Vertebrate evolution - recent perspectives from fish

Recent progress in understanding the evolution of vertebrate genomes has be en rapid, and previous nations that all such genomes could be regarded as e quivalent in their gene content have been rendered outdated. This notion, o ften embodied in the representation that vertebrates possess four Hox compl exes, still appears in contemporary textbooks of developmental biology. Rec ent data from the genomes of teleost fish show that this assumption is untr ue and suggest that interesting situations might arise from the apparent pr oliferation of genes among fish.