Phenotypic disparity in Iberian short-horned grasshoppers (Acrididae): the role of ecology and phylogeny

BMC Evolutionary Biology

Research Article

Joaquín Ortego¹  Vicente García-Navas¹  Víctor Noguerales²  Pedro J. Cordero² 

[1] Department of Integrative Ecology, Estación Biológica de Doñana (EBD-CSIC), Avenida Américo Vespucio 26, E-41092, Seville, Spain;Grupo de Investigación de la Biodiversidad Genética y Cultural, Instituto de Investigación en Recursos Cinegéticos IREC (CSIC-UCLM-JCCM), Ronda de Toledo 12, E-13071, Ciudad Real, Spain;

关键词: Ecomorphology;    Geometric morphometrics;    Phenotypic evolution;    Morphostatic radiation;    Orthoptera;    Tempo and mode;   

DOI  :  10.1186/s12862-017-0954-7

 received in 2017-01-30, accepted in 2017-04-19,  发布年份 2017

来源: Springer

【 摘 要 】

BackgroundThe combination of model-based comparative techniques, disparity analyses and ecomorphological correlations constitutes a powerful method to gain insight into the evolutionary mechanisms that shape morphological variation and speciation processes. In this study, we used a time-calibrated phylogeny of 70 Iberian species of short-horned grasshoppers (Acrididae) to test for patterns of morphological disparity in relation to their ecology and phylogenetic history. Specifically, we examined the role of substrate type and level of ecological specialization in driving different aspects of morphological evolution (locomotory traits, chemosensitive organs and cranial morphology) in this recent radiation.ResultsWe found a bimodal distribution of locomotory attributes corresponding to the two main substrate type guilds (plant vs. ground); plant-perching species tend to exhibit larger wings and thicker femora than those that remain on the ground. This suggests that life form (i.e., substrate type) is an important driving force in the evolution of morphological traits in short-horned grasshoppers, irrespective of ancestry. Substrate type and ecological specialization had no significant influence on head shape, a trait that showed a strong phylogenetic conservatism. Finally, we also found a marginal significant association between the length of antennae and the level of ecological specialization, suggesting that the development of sensory organs may be favored in specialist species.ConclusionsOur results provide evidence that even in taxonomic groups showing limited morphological and ecological disparity, natural selection seems to play a more important role than genetic drift in driving the speciation process. Overall, this study suggests that morphostatic radiations should not necessarily be considered as “non-adaptive” and that the speciation process can bind both adaptive divergence mechanisms and neutral speciation processes related with allopatric and/or reproductive isolation.

【 授权许可】

CC BY   
© The Author(s). 2017