The Emerging Phylogenetic Perspective on the Evolution of Actinopterygian Fishes

Abstract

The emergence of a new phylogeny of ray-finned fishes at the turn of the twenty-first century marked a paradigm shift in understanding the evolutionary history of half of living vertebrates. We review how the new ray-finned fish phylogeny radically departs from classical expectations based on morphology. We focus on evolutionary relationships that span the backbone of ray-finned fish phylogeny, from the earliest divergences among teleosts and nonteleosts to the resolution of major lineages of Percomorpha. Throughout, we feature advances gained by the new phylogeny toward a broader understanding of ray-finned fish evolutionary history and the implications for topics that span from the genetics of human health to reconsidering the concept of living fossils. Additionally, we discuss conceptual challenges that involve reconciling taxonomic classification with phylogenetic relationships and propose an alternate higher-level classification for Percomorpha. Our review highlights remaining areas of phylogenetic uncertainty and opportunities for comparative investigations empowered by this new phylogenetic perspective on ray-finned fishes. Expected final online publication date for the Annual Review of Ecology, Evolution, and Systematics, Volume 52 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Species delimitation and coexistence in an ancient, depauperate vertebrate clade

“…Major changes to biodiversity over the history of life on Earth have shaped extant species richness [ 1 , 68 , 78 ]. Although one end of the spectrum of biodiversity-radiations-are a historically well-studied evolutionary phenomenon [ 1 , 31 , 33 , 75 ], the origins of species-poor lineages that have persisted for millions or tens of millions of years are gaining attention (e.g., [ 22 , 23 , 57 ]. Phylogenomic studies now recognize depauperons across of different portions of the Tree of Life (e.g., [ 2 , 10 , 40 , 42 , 66 , 89 ]), demonstrating that depauperacy is a consistent evolutionary pattern.…”

Genome structures resolve the early diversification of teleost fishes

“…With more than 30,000 species, teleost fishes are by far the largest and the most diversified clade of extant vertebrates (2). Understanding their phylogeny has been and is still subject to many disputes at different taxonomic levels (2,3). Among these debates, a long-standing and unresolved question concerns the topology of the earliest-branching clades of crown teleosts, i.e., the Elopomorpha (named after "Elops-like" and including tarpon, bonefish and eels) and the Osteoglossomorpha (named after "bony-tongues" and including goldeye, arapaima, and elephantnose fish) relative to all the other extant teleosts in the Clupeocephala lineage (including for instance zebrafish, a major biomedical species) (3,4).…”

Switches, stability and reversals in the evolutionary history of sexual systems in fish

“…1 ). Furthermore, evolutionary transitions between sexual systems in teleost fish (~34000 species, comprising the overwhelming majority of the ray-finned fishes, Actinopterygii) 25 , might be less likely to occur via a mixed pathway (Fig. 1 ) given that in this group only a few killifish species of the genus Kryptolebias (formerly Rivulus ) are truly androdioecious 5 , 26 , 27 .…”