Answers are grounded in this paper and cite their sources.
An evolutionary hypothesis suggested by studies of the genome of the tiger pufferfish Takifugu rubripes has now been confirmed by comparison with the genome of a close relative, the spotted green pufferfish Tetraodon nigroviridis. Ray-finned fish underwent a whole-genome duplication some 350 million years ago that might explain their evolutionary success.
No takes yet. Share an insight, caveat, or question.
Yves Van de Peer (2004) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: