Evolutionary biology: The amphioxus unleashed.

The article discusses a research by N.H. Putnam and colleagues about the draft genome sequence of Branchiostoma floridae, one of the 25 or so recognized species of amphioxus. The draft genome highlights the basal position of the amphioxus, revealing strong patterns of conserved synteny with vertebrate genomes This extensive synteny has allowed insight into a suspected episode in the early history of vertebrates when the genome underwent tetrapolidization. Work on the amphioxus shows that two closely linked episodes of diploidization occurred at aroudn the time that the lineage of jawless vertebrates emerged.