Journal Article

Phenotypic diversification and island evolution of pipistrelle bats (Pipistrellus pipistrellus group) in the Mediterranean region inferred from geometric morphometrics and molecular phylogenetics

Hulva, Pavel, Horáček, Ivan, Evin, Allowen

2011

Overview

Aim: The Mediterranean Basin is a centre of radiation for numerous species groups. To increase our understanding of the mechanisms underlying speciation and radiation events in this region, we assessed the phenotypic variability within the Pipistrellus pipistrellus-pygmaeus-hanaki species complex. Although bats form the second largest mammalian order, studies of insular evolution in this group are scarce. We approached this problem from a microevolutionary perspective and tested for the recurrence of the insular syndrome. Location: The Mediterranean Basin, with a special focus on isolated populations from Corsica, the Maghreb, Cyprus, Cyrenaica and Crete. Methods: Phenotypic variability was assessed by cranial morphometrics using the coordinates of 41 3D landmarks and associated geometric-morphometric methods. We analysed 125 specimens representing all of the lineages in the species complex. Differences between taxa and between insular and continental populations in cranial size, shape, form and allometries were tested using analyses of variance and visualized using boxplots and canonical variate analysis. Relationships between molecular data from a previous study (cytochrome b sequences) and morphometric data were tested with co-inertia analyses (RV test) and multivariate regressions. Results: The three species were relatively well differentiated in cranial size and shape, and each species showed a significant amount of inter-population variability. Comparisons of pairs of insular versus continental populations revealed heterogeneities in cranial patterns among island phenotypes, suggesting no recurrent insular syndrome. Molecular and phenotypic traits were correlated, except for molecular and lateral cranium shape. Main conclusions: The Pipistrellus pipistrellus-pygmaeus-hanaki species complex exhibits phenotypic variability as a result of the fragmentation of its distribution (especially on islands), its phylogenetic and phylogeographic history and, most probably, other evolutionary factors that were not investigated in this study. We found no recurrent pattern of evolution on islands, indicating that sitespecific factors play a prevailing role on Mediterranean islands. The correlation between molecular and phenotypic data is incomplete, suggesting that factors other than phylogenetic relationships, potentially connected with feeding ecology, have played a role in shaping cranial morphology in this species complex.

• Publisher: Blackwell Publishing Ltd,Blackwell Publishing,Blackwell
• Subject: Allometry / analysis of variance / Animal and plant ecology / Animal, plant and microbial ecology / Bats / Biogeography / Biological and medical sciences / Biological taxonomies / Body size / Chiroptera / Corsica / cranial morphology / Cranium / Crete / Cyprus / cytochrome b / Ecological genetics / Evolution / Fundamental and applied biological sciences. Psychology / General aspects / Geographical variation in vertebrates / geometric morphometrics / insular syndrome / island evolution / islands / Maghreb / Mammalia / Mediterranean Basin / Mediterranean region / morphometry / phenotype / phenotypic evolution / phenotypic variation / phylogeny / Pipistrellus / Pipistrellus hanaki / Pipistrellus pipistrellus / Pipistrellus pygmaeus / Skull / species complex / Synecology / Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution / Zoology