Australian Rodents Reveal Conserved Cranial Evolutionary Allometry across 10 Million Years of Murid Evolution.
Am Nat
; 196(6): 755-768, 2020 12.
Article
em En
| MEDLINE
| ID: mdl-33211559
ABSTRACT
AbstractAmong vertebrates, placental mammals are particularly variable in the covariance between cranial shape and body size (allometry), with rodents being a major exception. Australian murid rodents allow an assessment of the cause of this anomaly because they radiated on an ecologically diverse continent notably lacking other terrestrial placentals. Here, we use 3D geometric morphometrics to quantify species-level and evolutionary allometries in 38 species (317 crania) from all Australian murid genera. We ask whether ecological opportunity resulted in greater allometric diversity compared with other rodents or whether conserved allometry suggests intrinsic constraints and/or stabilizing selection. We also assess whether cranial shape variation follows the proposed rule of craniofacial evolutionary allometry (CREA), whereby larger species have relatively longer snouts and smaller braincases. To ensure we could differentiate parallel versus nonparallel species-level allometric slopes, we compared the slopes of rarefied samples across all clades. We found exceedingly conserved allometry and CREA-like patterns across the 10-million-year split between Mus and Australian murids. This could support both intrinsic-constraint and stabilizing-selection hypotheses for conserved allometry. Large-bodied frugivores evolved faster than other species along the allometric trajectory, which could suggest stabilizing selection on the shape of the masticatory apparatus as body size changes.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Crânio
/
Tamanho Corporal
/
Muridae
Limite:
Animals
País/Região como assunto:
Oceania
Idioma:
En
Revista:
Am Nat
Ano de publicação:
2020
Tipo de documento:
Article
País de publicação:
EEUU
/
ESTADOS UNIDOS
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ESTADOS UNIDOS DA AMERICA
/
EUA
/
UNITED STATES
/
UNITED STATES OF AMERICA
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US
/
USA