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Little evidence for enhanced phenotypic evolution in early teleosts relative to their living fossil sister group.

ABSTRACT: Since Darwin, biologists have been struck by the extraordinary diversity of teleost fishes, particularly in contrast to their closest "living fossil" holostean relatives. Hypothesized drivers of teleost success include innovations in jaw mechanics, reproductive biology and, particularly at present, genomic architecture, yet all scenarios presuppose enhanced phenotypic diversification in teleosts. We test this key assumption by quantifying evolutionary rate and capacity for innovation in size and shape for the first 160 million y (Permian-Early Cretaceous) of evolution in neopterygian fishes (the more extensive clade containing teleosts and holosteans). We find that early teleosts do not show enhanced phenotypic evolution relative to holosteans. Instead, holostean rates and innovation often match or can even exceed those of stem-, crown-, and total-group teleosts, belying the living fossil reputation of their extant representatives. In addition, we find some evidence for heterogeneity within the teleost lineage. Although stem teleosts excel at discovering new body shapes, early crown-group taxa commonly display higher rates of shape evolution. However, the latter reflects low rates of shape evolution in stem teleosts relative to all other neopterygian taxa, rather than an exceptional feature of early crown teleosts. These results complement those emerging from studies of both extant teleosts as a whole and their sublineages, which generally fail to detect an association between genome duplication and significant shifts in rates of lineage diversification.

SUBMITTER: Clarke JT

PROVIDER: S-EPMC5068283 | biostudies-literature | 2016 Oct

REPOSITORIES: biostudies-literature

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Little evidence for enhanced phenotypic evolution in early teleosts relative to their living fossil sister group.

Clarke John T JT Lloyd Graeme T GT Friedman Matt M

Proceedings of the National Academy of Sciences of the United States of America 20160926 41

Since Darwin, biologists have been struck by the extraordinary diversity of teleost fishes, particularly in contrast to their closest "living fossil" holostean relatives. Hypothesized drivers of teleost success include innovations in jaw mechanics, reproductive biology and, particularly at present, genomic architecture, yet all scenarios presuppose enhanced phenotypic diversification in teleosts. We test this key assumption by quantifying evolutionary rate and capacity for innovation in size and ...[more]

PMID: 27671652

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Little evidence for enhanced phenotypic evolution in early teleosts relative to their living fossil sister group.

Publications

Little evidence for enhanced phenotypic evolution in early teleosts relative to their living fossil sister group.

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