Evolution of skull and body shape in Triturus newts reconstructed from three‐dimensional morphometric data and phylogeny

To explore the relationship between morphological change and species diversification, we reconstructed the evolutionary changes in skull size, skull shape, and body elongation in a monophyletic group of eight species that make up salamander genus Triturus. Their well‐studied phylogenetic relationships and the marked difference in ecological preferences among five species groups makes this genus an excellent model system for the study of morphological evolution. The study involved three‐dimensional imagery of the skull and the number of trunk vertebrae, in material that represents the morphological, spatial, and molecular diversity of the genus. Morphological change largely followed the pattern of descent. The reconstruction of ancestral skull shape indicated that morphological change was mostly confined to two episodes, corresponding to the ancestral lineage that all crested newts have in common and the Triturus dobrogicus lineage. When corrected for common descent, evolution of skull shape was correlated to change in skull size. Also, skull size and shape, as well as body shape, as inferred from the number of trunk vertebrae, were correlated, indicating a marked impact of species' ecological preferences on morphological evolution, accompanied by a series of niche shifts, with the most pronounced one in the T. dobrogicus lineage. The presence of phylogenetic signal and correlated evolutionary changes in skull and body shape suggested complex interplay of niche shifts, natural selection, and constraints by a common developmental system. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113 , 243–255.     

Ecological diversity and adaptive tendencies in the tropical fern Trichomanes L. (Hymenophyllaceae) with special reference to climbing and epiphytic habits

Among the basal fern families, the Hymenophyllaceae, with more than 600 species, display a high diversity in terms of their morphology and the habitats that they occupy. We have chosen to focus on Trichomanes L., a clearly defined genus for which a phylogeny is presently being developed, to investigate the appearance of the climbing and epiphytic habits, as well as the related supposed adaptive characters. In this study we present the first review of the different ecological types within the genus: terrestrial, climbing (divided into hemi-epiphytic forms and true lianas), and epiphytic types. The study of several features concerning stem morphology and leaf size allows a proposal on relationships between ecology and plant morphology. Terrestrial species display a thick monocaulous rhizome with robust roots and short internodes. Climbing species are characterized by a branched, thick, creeping rhizome with long internodes. Epiphytic species also exhibit long, creeping and branching stems with long internodes but the rhizome is fine to filiform. Under these circumstances, there is a reduction of root system and frond size leading to dwarfism in numerous instances. This may be related to an extreme hygrophilous epiphytic strategy. Finally, hypotheses on the evolution of these habits and hence on the evolutionary relationships between ecology and characters are presented and discussed.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 142 , 41–63.     

Song diversification and complexity in canaries and seedeaters (Serinus spp.)

Bird song is a composite trait that shows great variation in syntax and phonology between taxa, which hampers the precise quantification of complexity. This should be more feasible for closely-related species that share aspects of song organization. We conducted a comparative study of song and syllable characteristics in the largest fringillid genus, Serinus (canaries and seedeaters), with two objectives: (1) to describe and quantify song complexity in the genus and (2) to assess evolutionary dynamics of song, in particular whether interspecific song diversification evolved along intraspecific lines of covariation between syllable characteristics. We document a pattern of intense, very labile evolution of song in the genus. Well-known vocal constraints such as the relationship between frequency and body size did not appear to limit this evolution, and intraspecific trade-offs between different aspects of syllable complexity did not constrain interspecific diversification. Factor analysis returned an axis of variation that comprehensively expresses song complexity in the genus, and is defined by song speed, repertoire size, and also various aspects of syllable phonology. The species body size is not related to this axis of complexity, but to a minor axis that may indicate better respiratory capacity of larger birds. We discuss the pattern of song evolution in Serinus spp. in the context of the evolutionary dynamics of sexually selected traits.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 92 , 183–194.     

Phylogenetic relationships of the tribe Operophterini (Lepidoptera, Geometridae): a case study of the evolution of female flightlessness

A molecular phylogenetic analysis was conducted in order to reconstruct the evolution of female flightlessness in the geometrid tribe Operophterini (Lepidoptera, Geometridae, Larentiinae). DNA variation in four nuclear gene regions, segments D1 and D2 of 28S rRNA, elongation factor 1α , and wingless , was examined from 22 species representing seven tribes of Larentiinae and six outgroup species. Direct optimization was used to infer a phylogenetic hypothesis from the combined sequence data set. The results obtained confirmed that Operophterini (including Malacodea ) is a monophyletic group, and Perizomini is its sister group. Within Operophterini, the genus Malacodea is the sister group to the genera Operophtera and Epirrita , which form a monophyletic group. This relationship is also supported by morphological data. The results suggest that female flightlessness has evolved independently twice: first in the lineage of Malacodea and, for the second time, in the lineage of Operophtera after its separation from the lineage of Epirrita . An alternative reconstruction (i.e. recovery of flight ability in an ancestor of Epirrita ) appears unlikely for various reasons. The similarities shared by Epirrita with a basal representative of Perizomini, Perizoma didymatum , allow the proposal of a sequence of evolutionary events that has led to flightlessness. It is likely that the transition to female flightlessness in the two lineages of Operophterini occurred after the colonization of stable forest habitats, followed by the evolution of a specific set of permissive traits, including larval polyphagy, limited importance of adult feeding, and adult flight during the cold months of the season.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 92 , 241–252.     

Chromosome counts in Asian Artemisia L. (Asteraceae) species: from diploids to the first report of the highest polyploid in the genus

This work comprises 24 reports of chromosome numbers in 24 Artemisia L. species from Asia. Ten are included in the subgenus Dracunculus Besser and the rest belong to other subgenera. Seven counts are new reports, 14 are consistent with scarce previous ones, and three contribute new ploidy levels. That carried out in A. medioxima reports the highest ploidy level ever counted for the genus (16 x ). There is only one species with x  = 8 as the basic chromosome number. In the remaining x  = 9-based species, ploidy levels range from 2 x to 16 x , illustrating the great role played by polyploidy in the evolution of the genus.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 301–310.     

Recurrent polymorphic mating type variation in Madagascan Bulbophyllum species (Orchidaceae) exemplifies a high incidence of auto‐pollination in tropical orchids

The transition from outcrossing to self‐fertilization is one of the most common evolutionary changes in angiosperms. The orchid family exemplifies this evolutionary trend but, because of a general lack of large‐scale surveys on auto‐pollination in orchid taxa, the incidence and modes of auto‐pollination among (sub)tropical orchids remain poorly known. In the present study, we assessed the frequency and mode of auto‐pollination within and among species of a largely monophyletic group of Madagascan Bulbophyllum. The capacity for autonomous fruit set was investigated by bagging experiments in the greenhouse and the field, complemented with detailed floral micromorphological studies of the gynostemium. Our survey comprises 393 accessions, representing at least 78 species, and thus approximately 37% of the species diversity of the genus in the Madagascan region. Our studies revealed that mating type is directly related to gynostemium structure, most often involving the presence or absence of a physical barrier termed ‘rostellum’. As a novel and unexpected finding, we identified eight species of a single lineage of Madagascan Bulbophyllum (termed ‘clade C’), in which auto‐pollinating morphs (selfers), either lacking a rostellum or (rarely) possessing a stigmatic rostellum, co‐exist with their pollinator‐dependent conspecifics (outcrossers). We hypothesize that auto‐pollination via rostellum abortion has a simple genetic basis, and probably evolved rapidly and recurrently by subtle changes in the timing of rostellum development (heterochrony). Thus, species of clade C may have an intrinsic genetic and developmental lability toward auto‐pollination, allowing rapid evolutionary response under environmental, perhaps human‐disturbed conditions favouring reproductive assurance. Overall, these findings should stimulate further research on the incidence, evolution, and maintenance of mating type variation in tropical orchids, as well as how they adapt(ed) to changing environmental conditions. © 2014 The Authors. Botanical Journal of the Linnean Society published by John Wiley & Sons Ltd on behalf of The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175 , 242–258.     

Leaf and stem anatomy of Vochysiaceae in relation to subfamilial and suprafamilial systematics

Several leaf anatomical features are potentially systematically informative within both the family Vochysiaceae and the order Myrtales, notably tracheoidal idioblasts, mucilage cells and secretory canals. Tracheoids with spiral wall thickenings are present in the mesophyll of most species of Vochysia , and also occur in several other families of Myrtales. Mucilage cells are common in the leaf epidermis in some Vochysiaceae. Secretory ducts are present in the midrib in Salvertia and Vochysia , which are apparently closely related, although Salvertia also shares some leaf anatomical characters with Qualea and Callisthene . Anatomical data do not support the segregation of Ruizterania from Qualea ; leaves of R. albiflora leaves are very similar to those of Q. paraensis in venation pattern, and leaf and stem anatomy. Different venation patterns are characteristic of sections within the genus Qualea , but within the large genus Vochysia , leaf anatomy is variable even within a subsection. Amongst other Myrtales, leaf anatomy of Vochysiaceae most closely resembles that of Combretaceae and Onagraceae. © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 138 , 339–364.     

Systematics of the genera of Bodotriidae (Crustacea: Cumacea)

The cumacean family Bodotriidae includes 382 species in 31 genera grouped in three subfamilies: Bodotriinae, Mancocumatinae and Vaunthompsoniinae. Generic diagnoses are based on few characters that often have overlapping states among genera, complicating the understanding of the relationships within the group. The goals of this study are to illuminate the phylogenetic relationships among the genera of the Bodotriidae using morphological characters and to review the systematics of the family. For this purpose, all species within each genus were studied from the literature to code all the variability of genera for 109 variable morphological characters. Phylogenetic analyses show that there is independent reduction of the pleopods in two clades from a plesiomorphic state of five pairs, while the number of exopods of peraeopods has been reduced gradually in more derived groups of bodotriids. The subfamily Bodotriinae is the most derived and the Vaunthompsoniinae the most basal, and is paraphyletic with the Mancocumatinae embedded within it. No discriminatory characters were found between the subfamilies Mancocumatinae and Vaunthompsoniinae and they are not clearly separated in the phylogeny. Mancocumatinae is synonymized with Vaunthompsoniinae and all the genera of the former Mancocumatinae should be included within Vaunthompsoniinae. Analyses of character evolution justify a few other taxonomic changes. All genera were redescribed based on all the coded characters and a complete list of all valid species for each genus is included. Finally, dichotomous keys for identification to genus level are provided.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 151 , 1–58.     

Description, biology and conservation of a new species of Australian tree frog (Amphibia: Anura: Hylidae: Litoria) and an assessment of the remaining populations of Litoria genimaculata Horst, 1883: systematic and conservation implications of an unusual speciation event

The Australian populations of the green-eyed tree frog Litoria genimaculata consist of a northern and southern genetic lineage that meet in a mosaic contact zone comprising two independent areas of contact: one where the main ranges of the lineages overlap, and the second where a population of the southern lineage is isolated within the range of the northern lineage. A recent study failed to find significant reproductive isolation between the main ranges of the two lineages, despite deep genetic divergence, partial postzygotic isolation, and call differences. The study did, however, demonstrate rapid phenotypic divergence and speciation of the isolated population of the southern lineage from both the parapatric northern lineage and from the allopatric, but genetically similar, main range of the southern lineage. Herein, the isolated population of the southern lineage is described as a distinct species, Litoria myola sp. nov. , whereas the remainder of the southern lineage and the northern lineage are retained as a single, paraphyletic species, Litoria genimaculata . Resolving this unusual systematic situation demonstrates the value of using multiple lines of evidence in delimiting species. Litoria myola sp. nov. has a very small distribution and population size and warrants a Critically Endangered listing (B1, 2) under IUCN criteria. Threats and management recommendations are outlined, and the conservation of hybrid zones as areas of evolutionary novelty is discussed.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 91 , 549–563.     

Relationships, classification and evolution of Scleranthus (Caryophyllaceae) as inferred from analysis of morphological characters

Study of floral anatomy, micromorphology, palynology and onotogeny has revealed new characters for phylogenetic analysis in the genus Scleranthus . Cladistic analysis of these characters, along with those previously available, suggests that the genus consists of Eurasian/Mediterranean and Australasian sister clades. Gynoecial morphology and development are closely similar in all species, suggesting the genus is monophyletic despite its disjunct northern and southern hemisphere distribution. Variation in pollen:ovule ratios and their implications for the evolution of Scleranthus species are also discussed and it is concluded that a range of breeding strategies intermediate between autogamy and xenogamy exists in the genus. Single-stamened species of Scleranthus are likely to be obligate autogams, despite their comparatively high pollen:ovule ratios in relation to autogamic species of other genera.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 140 , 15–29.     

Delimiting species in the hoplonemertean genus Tetrastemma (phylum Nemertea): morphology is not concordant with phylogeny as evidenced from mtDNA sequences

The marine genus Tetrastemma contains monostiliferous hoplonemertean (phylum Nemertea) species which mostly undergo direct development with no free-swimming stages of larvae. The lack of a pelagic phase, and the fact that many benthic species lay eggs attached to the bottom substrate, are obvious restrictions on dispersal and gene flow. Nevertheless, some of the species, for example T. candidum and T. melanocephalum , are described as ubiquitous and are reported from waters all over the world. We studied genetic variation and evolutionary relationships in order to assess whether they are concordant with external characters in samples of nine morphologically distinct forms formally named as different Tetrastemma species, from different geographical localities. We estimated the phylogeny and species network based on 539 base pairs of the mitochondrial protein-coding gene cytochrome oxidase-1 (CO1) for 30 ingroup specimens. From this, we assessed the evolutionary history and phylogenetic relationships between these forms. We conclude that in most cases there was no correspondence between evolutionary lineage and morphotype. Our results thus indicate that morphological species delimitation in nemerteans may be questionable, and that this in turn may have a profound effect upon estimates of species diversity within the phylum.  © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 86 , 201–212.     

Intraspecific range dynamics and niche evolution in Candidula land snail species

The range dynamics of a species can either be governed by the spatial tracing of the fundamental environmental niche or by adaptation that allows to occupy new niches. Therefore, the investigation of spatial variation in the realized environmental niche is central to the understanding of species range limit dynamics. However, the study of intraspecific niche variation has been neglected in most phylogeographical studies. We studied the spatial distribution of the realized environmental niche in three land snail species of the genus Candidula , integrating phylogeographical methods, morphometrics, and spatial biodiversity informatics . The phylogeographical analyses showed significant range expansions in all species. These expansions were accompanied in Candidula gigaxii by a shift in the realized environmental niche, the species Candidula unifasciata followed its ancestral niche during expansion while the climate changed in the area of origin and Candidula rugosiuscula tracked the ancestral environmental conditions. The significant niche shifts were associated with potentially adaptive changes of shell morphology. We propose our presented approach as a practicable framework to test hypotheses on intraspecific niche evolution. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 90 , 303–317.     

An inquiline fig wasp using seeds as a resource for small male production: a potential first step for the evolution of new feeding habits?

The processes allowing evolutionary transitions in resources used by parasitic wasps are largely unknown. Microhymenopteran communities associated with figs could provide a model system to investigate such transitions. We investigate here a species of genus Idarnes . The larvae generally develop as inquilines of the pollinating wasp larvae. However, in figs where the parasitic pressure is high, eggs are laid in developing seeds. These eggs turn into small males. This is the first report of seed consumption by a fig wasp. Using an alternative resource to produce small males could provide a pathway to select for increased ability to use this resource and hence provide an intermediate step for evolving the capacity to use new resources.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 92 , 9–17.     

Electrophoretic characterization of Amaranthus L. seed proteins and its systematic implications

The seed protein profiles of 11 Amaranthus taxa (Amaranthaceae) from Spain were studied. These profiles were evaluated as a chemical character to clarify the taxonomic complexity in the genus. Tricine-sodium dodecylsulphate-polyacrylamide gel electrophoresis (SDS-PAGE) profiles of the Amaranthus seed proteins studied showed a range of peptides varying from 64 to 12 kDa, with a larger number of protein bands observed between 25.1 and 12 kDa. For the taxonomic study, 14 bands, some of them subdivided into several isoforms, were considered. The similarity analysis based on the SDS-PAGE profile is a useful character for the discrimination of species in Amaranthus , except for A. cruentus and A. hypochondriacus , for which a hybrid population was found. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 57–63.     

Lineage specific evolution of an alternative social strategy in Tetramorium ants (Hymenoptera: Formicidae)

The western Palearctic ant, Tetramorium moravicum , is the only species of the large genus known to display two alternative social strategies: macrogyny-monoygyny (characterized by one large queen per colony) and microgyny-polygyny (multiple small queens per colony). The microgyne colonies of this ant are confined to the westernmost part of its distribution area and occasionally co-occur with macrogyne colonies. We investigated phylogenetic and geographical patterns in relation to social strategy by analysing 1031 bp of the mitochondrial cytochrome c oxidase subunit I gene of T. moravicum from the entire known species range. Phylogenetic analyses revealed two clear-cut lineages coinciding with the eastern and western populations, which probably were separated after the late Quaternary glacial periods. Geographical distance analysis suggested allopatric fragmentation of the two lineages. We hypothesize that the two lineages colonized Central Europe postglacially from two directions. The current distribution gap of 500 km between the tip of the eastern lineage, in the Czech Republic, Austria and Hungary, and the western lineage, in Germany, was confirmed by hierarchical population analysis. Macrogyny-monogyny probably was the original condition in T. moravicum ; the alternative strategy of microgyny-polygyny may have evolved at the tip of the western lineage, as recently as the early Holocene.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 91 , 247–255.     

Adaptive radiation in miniature: the minute salamanders of the Mexican highlands (Amphibia: Plethodontidae: Thorius)

The small size and apparent external morphological similarity of the minute salamanders of the genus Thorius have long hindered evolutionary studies of the group. We estimate gene and species trees within the genus using mitochondrial and nuclear DNA from nearly all named and many candidate species and find three main clades. We use this phylogenetic hypothesis to examine patterns of morphological evolution and species coexistence across central and southern Mexico and to test alternative hypotheses of lineage divergence with and without ecomorphological divergence. Sympatric species differ in body size more than expected after accounting for phylogenetic relationship, and morphological traits show no significant phylogenetic signal. Sympatric species tend to differ in a combination of body size, presence or absence of maxillary teeth, and relative limb or tail length, even when they are close relatives. Sister species of Thorius tend to occupy climatically similar environments, which suggests that divergence across climatic gradients does not drive species formation in the genus. Rather than being an example of cryptic species formation, Thorius more closely resembles an adaptive radiation, with ecomorphological divergence that is bounded by organism‐level constraints. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109 , 622–643.     

The skull of the rare Malaysian snake Anomochilus leonardi Smith, based on high-resolution X-ray computed tomography

The skull of the rare Malaysian snake Anomochilus leonardi is described in detail on the basis of a high-resolution X-ray computed tomographic scan of a mature specimen. Its skull anatomy is compared with that of Anomochilus weberi , as well as with that of scolecophidians and basal alethinophidians such as Anilius , Cylindrophis , uropeltines and selected Booidea. Anomochilus leonardi is found to be more paedomorphic than Anomochilus weberi . The genus Anomochilus most closely resembles uropeltines in skull anatomy. Both Anomochilus and uropeltines develop a 'central rod design' of skull morphology, which requires the presence of medial frontal pillars, in adaptation to burrowing habits. These pillars are an alethinophidian characteristic, absent in the skull of scolecophidians, which develop an 'outer shell design' in adaptation to burrowing. These results are discussed in the light of the hypothesis that scolecophidians and basal (i.e. non-macrostomatan) alethinophidians are 'regressed macrostomatans'.  © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society , 2007, 149 , 671–685.     

Systematic implications of wood and bark anatomy in the Pacific Island genus Meryta (Araliaceae)

Wood anatomy was examined in 16 species of Meryta (a genus of c . 35 species) and bark anatomy was studied in 12 species. All but two of these taxa form an assemblage corresponding to the Northern Arc clade, one of two major groups identified by a recent molecular phylogenetic study. M. sinclairii and M. tenuifolia (corresponding to the New Zealand/Fiji clade) differ distinctly by having more numerous simple perforation plates, multiseriate rays with few marginal rows, and the absence of sclerified cells in collapsed secondary phloem, a bark feature that has not yet been found elsewhere in Araliaceae. The increase in abundance of simple perforation plates in the wood of these two species is not accompanied by a decrease in the number of bars on scalariform perforation plates. The wood structure of Meryta bears a strong resemblance to members of the Pacific Schefflera clade, sharing similar ranges of variation of several features. Bark characters, such as the diameter of the cortical secretory canals, the types of crystal in cortical cells, the types of axial parenchyma cell in collapsed secondary phloem, and the presence of sheath cells by phloem rays, appear to be of diagnostic value for some species of Meryta .  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 363–379.