TY - JOUR
T1 - Little evidence for enhanced phenotypic evolution in early teleosts relative to their living fossil sister group
AU - Clarke, John T.
AU - Lloyd, Graeme T.
AU - Friedman, Matt
PY - 2016/10/11
Y1 - 2016/10/11
N2 - 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.
AB - 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.
KW - neopterygian
KW - phylogeny
KW - genome duplication
KW - fossil record
KW - morphological diversification
UR - http://purl.org/au-research/grants/arc/DE140101879
UR - http://www.scopus.com/inward/record.url?scp=84991508650&partnerID=8YFLogxK
U2 - 10.1073/pnas.1607237113
DO - 10.1073/pnas.1607237113
M3 - Article
C2 - 27671652
SN - 0027-8424
VL - 113
SP - 11531
EP - 11536
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 41
ER -