Showing papers in "Biological Journal of The Linnean Society in 2014"
TL;DR: The most heterogeneous places in terms of distributional patterns can be defined numerically on strictly geographical grounds by plotting the frequency of different distribution patterns on maps, and gradual changes in their relative contribution to a given area can be perceived.
Abstract: We revise concepts, definitions and examples of biogeographical transition zones to help develop a conceptual framework and differentiate them from other transitions that occur in the geographical space. A biogeographical transition zone is defined as a geographical area of overlap, with a gradient of replacement and partial segregation between biotic components (sets of taxa that share a similar geographical distribution as a product of a common history). It is an area where physical features, environmental conditions and ecological factors allow the mixture and the co-occurrence of two or more biotic components, but also constrain their distribution further into one another. The biogeographical affinities of the taxa are the most fundamental information to consider to analyse biogeographical transition zones accurately. By plotting the frequency of different distribution patterns on maps, gradual changes in their relative contribution to a given area can be perceived. Thus, the most heterogeneous places in terms of distributional patterns can be defined numerically on strictly geographical grounds. Biogeographical transition zones can occur at every hierarchical level of a biogeographical regionalization as long as different biotic components come into contact geographically. Ecological boundaries or ecotones when characterized only by differences in dominance of some species, life forms or sets of characteristic species (not endemic) are not biogeographical transition zones as defined herein. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113, 1–12.
100 citations
TL;DR: It is suggested that both endemism patterns and cross-taxa concordant phylogeographic patterns across the Iberian Peninsula to some extent are linked to spatial variation in Late Quaternary climate stability, in agreement with the proposed ‘Refugia-within-refugia’ scenario.
Abstract: In Europe, southern peninsulas served as major refugia during Pleistocene cold periods. However, growing evidence has revealed complex patterns of glacial survival within these southern regions, with multiple glacial refugia within each larger refugial area. We investigated the extent to which patterns of endemism and phylogeographic are concordant across animal species in the Iberian Peninsula, one of the most important unglaciated areas in Europe during the Pleistocene, can be explained in terms of climatic stability. We found that historical climatic stability (notably climate velocity measures integrating macroclimatic shifts with local spatial topoclimate gradients) was often among the most important predictors of endemic species richness for different taxonomic groups using models that also incorporated measures of modern climate. Furthermore, for some taxonomic groups, climatic stability was also correlated with patterns of spatial concordance in interpopulation genetic divergence across multiple taxa, and private haplotypes were more frequently found in relatively stable areas. Overall, our results suggest that both endemism patterns and cross-taxa concordant phylogeographic patterns across the Iberian Peninsula to some extent are linked to spatial variation in Late Quaternary climate stability, in agreement with the proposed ‘refugia-within-refugia’ scenario. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113, 13–28.
86 citations
TL;DR: A new approach of bone tissue classification and description that is congruent with the current understanding of bone as a living tissue, emphasizing its developmental aspects is suggested, namely ‘woven-parallel complex’.
Abstract: Research on the bone histology of extant and extinct animals has a long scientific history and an accurate description of microstructural tissues is the cornerstone of the field. Ideally, terminology needs to convey as much information as possible about the structural, developmental, and functional aspects of bone tissues corresponding to the up-to-date knowledge of the time. However, current terms are not always consistent with new observations and advances in the field of bone biology. We provide a brief overview of some ambiguities and their origins, and suggest a new approach of bone tissue classification and description that is congruent with our current understanding of bone as a living tissue, emphasizing its developmental aspects. This approach requires the introduction of a new term, namely ‘woven-parallel complex’, for describing a broad range of complex bone tissue types, including intramembranous and endochondral bones, and different types of primary as well as secondary bone tissues. We reconsider the classical concept of fibrolamellar complex, which we place within the new developmental approach. Finally, using non-archosaurian archosauromorphs as an example group, we demonstrate how the new approach can be utilized in an evolutionary context. The present study demonstrates the relevance and constant evolution of technical terminology along with the advances of the field of science. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112, 799–816.
81 citations
TL;DR: This study suggests that geographical variation in dorsal coloration in this lizard is adaptive, and darkness coloration might have evolved in response to adverse conditions (low temperature and high UV radiation) at high altitudes.
Abstract: Altitudinal gradients offer a good opportunity to study organisms' adaptations to clinal environmental variables. Regarding altitude, the most influential variables on organisms are temperature and ultraviolet (UV) solar radiation, the first decreasing and the second increasing with altitude. Both variables affect ectotherms' biology, as ectotherms depend on environmental temperature for thermoregulation, frequently being heliotherms. Here, we studied dorsal coloration in the lizard Psammodromus algirus (Linnaeus, 1758) along a wide altitudinal gradient (2200 m) in Sierra Nevada (south-east Spain). We hypothesize that the skin will be darker with altitude, i.e. in environments with lower temperatures and higher UV radiation intensity. Results show that individual dorsal colorations became darker at high altitude. We propose two non-mutually exclusive explanations for this result: (1) darker dorsal surface would favour faster warming at high altitudes, where temperature is lower, and (2) darker dorsal surface would protect against UV radiation, stronger at high altitudes. We found significant relationships between both temperature and UV radiation and population dorsal darkness, giving mixed support for the two explanations. Moreover, dorsal hue was positively correlated with substrate hue, suggesting that hue evolved to maximize crypsis. Our study therefore suggests that geographical variation in dorsal coloration in this lizard is adaptive, and darkness coloration might have evolved in response to adverse conditions (low temperature and high UV radiation) at high altitudes. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014,112, 132–141.
72 citations
TL;DR: This paper aims to demonstrate the efforts towards in-situ applicability of EMMARM, as to provide real-time information about concrete mechanical properties such as E-modulus and compressive strength and high-resolution X-ray diffraction analysis.
Abstract: National Basic Research Program of China (973 Program) [2012CB821906]; National Natural Science Foundation of China [41172020, 41372014]
61 citations
TL;DR: Over all transects, there is a weak negative relationship between the level of hybridization and allozyme genetic distance for species pairs, consistent with Bateson–Dobzhansky–Muller effects.
Abstract: The shape of hybrid zones provides insight into genetic isolation between the evolutionary lineages involved: the greater the limitation to gene flow, the farther along the unimodal to bimodal continuum We study hybrid zone modality in a group of closely related species at a variety of levels of genetic divergence We explore the degree and the geography of hybridization in 12 transects of Triturus newts, for nine of the ten secondary contact zones in Europe, using nuclear and mitochondrial encoded genetic data and morphological characteristics Species status is verified by examining the correlation between the three marker systems in a geographical context At 40 allozyme loci, two transects classify as unimodal, three as bimodal and two as intermediate, while the signal for hybridization is weak or absent in five transects One zone studied in duplicate was classified as intermediate in one region and as bimodal in another region mtDNA introgression is frequent and extends beyond nuclear introgression in two transects Morphology provides additional evidence for hybridity, including one transect for which the signal of nuclear gene flow is weak Compared to simulations allowing panmixia, the observed allozyme transitions at contact zones show a deficit of backcrossing to various degrees Over all transects, there is a weak negative relationship between the level of hybridization and allozyme genetic distance for species pairs, consistent with Bateson–Dobzhansky–Muller effects This observation, based upon highly comparable data for a single genus, supports conclusions derived from analyses over a wide variety of other taxa © 2014 The Authors Biological Journal of the Linnean Society published by John Wiley & Sons Ltd on behalf of The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113, 604–622
60 citations
TL;DR: The idea that behaviour has played an important role in evolution has had its ups and downs over the past two centuries, but now it appears to be up once again, with ‘multilevel selection theory’ providing a more ecumenical, multicausal model of evolutionary change.
Abstract: The idea that behaviour has played an important role in evolution has had its ups and downs over the past two centuries. Now it appears to be up once again. Lamarck can claim priority for this insight, along with Darwin's more guarded view. However, there followed a long ‘dark-age’, which began with Weismann's mutation theory and spanned the gene-centred era that followed during most of the 20th Century, although it was punctuated by various contrarians, from Baldwin's ‘Organic Selection theory’ to Simpson's ‘Baldwin effect’, Mayr's ‘Pacemaker’ model, and Waddington's ‘genetic assimilation’, amongst others. Nowadays, even as we are reading genomes and using this information to illuminate biological causation and decipher evolutionary patterns, behavioural processes are more fully appreciated, with ‘multilevel selection theory’ providing a more ecumenical, multicausal model of evolutionary change. This has been accompanied by a flood of research on how behavioural influences contribute to the ongoing evolutionary process, from research on phenotypic plasticity to niche construction theory and gene–culture co-evolution theory. However, the theoretical implications of this paradigm shift still have not been fully integrated into our current thinking about evolution. Behaviour has a purpose (teleonomy); it is ends-directed. Living organisms are not passive objects of ‘chance and necessity’ (as Jacques Monod put it). Nor is the currently popular concept of phenotypic plasticity sufficient. Organisms are active participants in the evolutionary process (cybernetic systems) and have played a major causal role in determining its direction. It could be called ‘constrained purposiveness’, and one of the important themes in evolution, culminating in humankind, has been the ‘progressive’ evolution of self-determination (intelligence) and its ever-expanding potency. I call this agency ‘Teleonomic Selection’. In a very real sense, our species invented itself. For better and worse, the course of evolution is increasingly being shaped by the ‘Sorcerer's Apprentice’. Monod's mantra needs to be updated. Evolution is a process that combines ‘chance, necessity, teleonomy and selection’. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112, 242–260.
59 citations
TL;DR: This paper aims to demonstrate the efforts towards in-situ applicability of EMMARM, which aims to provide real-time information about bark beetle infestation in the Pacific Ocean.
Abstract: Department of Global Ecology, Carnegie Institution for Science, Stanford, CA 94305, USA Department of Natural Resources and Environmental Management, University of Hawai‘i at Mânoa, Honolulu, HI 96822, USA Institute of Pacific Islands Forestry, USDA Forest Service, Hilo, HI 96720, USA Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, WI 53211, USA Smithsonian Tropical Research Institute, Apartado 2072, Balboa, Republic of Panama
59 citations
TL;DR: This study examines the head morphology and feeding ecology of island and mainland populations of the Balkan green lizard, Lacerta trilineata and suggests that insularity influences feeding ecology and, through selection on bite force, head morphology.
Abstract: Island environments differ with regard to numerous features from the mainland and may induce large-scale changes in most aspects of the biology of an organism. In this study, we explore the effect of insularity on the morphology and performance of the feeding apparatus, a system crucial for the survival of organisms. To this end, we examined the head morphology and feeding ecology of island and mainland populations of the Balkan green lizard, Lacerta trilineata. We predicted that head morphology, performance and diet composition would differ between sexes and habitats as a result of varying sexual and natural selection pressures. We employed geometric morphometrics to test for differences in head morphology, measured bite forces and analysed the diet of 154 adult lizards. Morphological analyses revealed significant differences between sexes and also between mainland and island populations. Relative to females, males had larger heads, a stronger bite and consumed harder prey than females. Moreover, island lizards differed in head shape, but not in head size, and, in the case of males, demonstrated a higher bite force. Islanders had a wider food niche breadth and included more plant material in their diet. Our findings suggest that insularity influences feeding ecology and, through selection on bite force, head morphology. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112, 469–484.
59 citations
TL;DR: In this article, a molecular phylogeny focused on resolving the deepest divergences among the free-living Platyhelminthes is presented, which corroborates the classical hypothesis of homology between yolk cells and oocytes in all Neoophora, and also resolve a clade possessing distinct yolk-cell and oocyte generating organs.
Abstract: Ectolecithality is a form of oogenesis unique within Metazoa but common in Platyhelminthes, in which almost yolkless oocytes and tightly associated yolk cells are deposited together in egg capsules. Despite profound impacts on the embryogenesis and morphology of its beneficiaries, the origins of this developmental phenomenon remain obscure. Traditionally, all ectolecithal flatworms were grouped in a clade called Neoophora. However, there are also morphological arguments for multiple origins of ectolecithality and, to date, Neoophora has seen little support from molecular phylogenetic research, largely as a result of gaps in taxon sampling. Accordingly, we present a molecular phylogeny focused on resolving the deepest divergences among the free-living Platyhelminthes. Species were chosen to completely span the diversity of all major endo- and ectolecithal clades, including several aberrant species of uncertain systematic affinity and, additionally, a thorough sampling of the ‘lecithoepitheliate’ higher taxa Prorhynchida and Gnosonesimida, respectively, under- and unrepresented in phylogenies to date. Our analyses validate the monophyly of all classical higher platyhelminth taxa, and also resolve a clade possessing distinct yolk-cell and oocyte generating organs (which we name Euneoophora new taxon). Furthermore, implied-weights parsimony and Bayesian mixture model analyses suggest common ancestry of this clade with the lecithoepitheliates, implying that these taxa may retain a primitive form of ectolecithality. This topology thus corroborates the classical hypothesis of homology between yolk cells and oocytes in all Neoophora, and should serve to guide future evolutionary research on this unique developmental innovation in Platyhelminthes. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 570–588.
58 citations
TL;DR: It is concluded that there is considerable variation in the morphology of the holotypes, as well as variation in size and quality of the samples and the mode of preservation, which makes it difficult to synonymize any of the existing ichnotaxa without detailed revision of theamples from which the type material originates.
Abstract: Trackways of ornithopods are well-known from the Lower Cretaceous of Europe, North America, and East Asia. For historical reasons, most large ornithopod footprints are associated with the genus Iguanodon or, more generally, with the family Iguanodontidae. Moreover, this general category of footprints is considered to be sufficiently dominant at this time as to characterize a global Early Cretaceous biochron. However, six valid ornithopod ichnogenera have been named from the Cretaceous, including several that are represented by multiple ichnospecies: these are Amblydactylus (two ichnospecies); Caririchnium (four ichnospecies); Iguanodontipus, Ornithopodichnus originally named from Lower Cretaceous deposits and Hadrosauropodus (two ichnospecies); and Jiayinosauropus based on Upper Cretaceous tracks. It has recently been suggested that ornithopod ichnotaxonomy is oversplit and that Caririchnium is a senior subjective synonym of Hadrosauropodus and Amblydactylus is a senior subjective synonym of Iguanodontipus. Although it is agreed that many ornithopod tracks are difficult to differentiate, this proposed synonymy is questionable because it was not based on a detailed study of the holotypes, and did not consider all valid ornithopod ichnotaxa or the variation reported within the six named ichnogenera and 11 named ichnospecies reviewed here. We therefore emphasize the need to base comparisons between ichnotaxa on type material, and not on selected referred material. It is concluded that there is considerable variation in the morphology of the holotypes, as well as variation in size and quality of the samples and the mode of preservation. Conversely, there is considerable overlap in morphology among other tracks that have been informally attributed to these ichnotaxa. These factors make it difficult to synonymize any of the existing ichnotaxa without detailed revision of the samples from which the type material originates. Nevertheless, a review of the type material of all ichnotaxa is presented as a basis for further discussion and, as a first step, the ichnofamily Iguanodontipodidae is proposed to accommodate Amblydactylus, Caririchnium and Iguanodontipus, © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113, 721–736.
TL;DR: Among the polylectic species, several intriguing patterns of host plant use were found, suggesting that host plant choice of these bees is constrained to different degrees and governed by flower morphology, pollen chemistry or nectar availability, thus supporting previous findings on predominantly oligolectic clades of bees.
Abstract: Within the genus Osmia, the three subgenera Osmia, Monosmia, and Orientosmia form a closely-related group of predominantly pollen generalist (‘polylectic’) mason bees. Despite the great scientific and economic interest in several species of this clade, which are promoted commercially for orchard pollination, their phylogenetic relationships remain poorly understood. We inferred the phylogeny of 21 Osmia species belonging to this clade by applying Bayesian and maximum likelihood methods based on five genes and morphology. Because our results revealed paraphyly of the largest subgenus (Osmia s.s.), we synonymized Monosmia and Orientosmia under Osmia s.s. Microscopical analysis of female pollen loads revealed that five species are specialized (‘oligolectic’) on Fabaceae or Boraginaceae, whereas the remaining species are polylectic, harvesting pollen from up to 19 plant families. Polylecty appears to be the ancestral state, with oligolectic lineages having evolved twice independently. Among the polylectic species, several intriguing patterns of host plant use were found, suggesting that host plant choice of these bees is constrained to different degrees and governed by flower morphology, pollen chemistry or nectar availability, thus supporting previous findings on predominantly oligolectic clades of bees. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 78–91.
TL;DR: This study investigates the role of ant dominance hierarchy in structuring an ecological network involving ants and EFN-bearing plants in a tropical coastal environment in Mexico and shows that within a nested ant–plant network, ant species found in the central core of highly interacting species were competitively superior, showing massive recruitment and resource domination.
Abstract: Extrafloral nectar (EFN) is a predictable and renewable resource for many ant colonies, and different ant species compete strongly to obtain and monopolize this highly nutritious food resource. Despite the importance of competition in structuring patterns of ant–plant interactions, this biological mechanism has been largely ignored in studies involving ant–plant networks. In this study we investigate the role of ant dominance hierarchy in structuring an ecological network involving ants and EFN-bearing plants in a tropical coastal environment in Mexico. We show that within a nested ant–plant network, ant species found in the central core of highly interacting species were competitively superior, showing massive recruitment and resource domination, compared with peripheral species with fewer interactions. Moreover, we also observed that both central and peripheral ant species have the ability to quickly find the food resource. However, after 2 h of observation, central ant species are more frequently collected on the food resource when compared with peripheral species. We hypothesize that the existence of a central core of competitive ant species may indicate that most plant species found within ant–plant networks could be better protected against herbivory by these dominant ant species. In short, our results highlight the importance of competition and monopolization in the resource use by ants in the maintenance of the nested pattern in ant–plant mutualistic networks. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113, 405–414.
TL;DR: The broad overlap in compactness values between the lifestyles and the lack of tubular structure in all turtles, however, suggest that selection pressure of skeletal lightening in terrestrial turtles is not high enough to cause a tubularructure, and suggests that the humeral compactness could not be used alone to provide an indication of lifestyle in turtles.
Abstract: Among living turtles, highly terrestrial or highly aquatic modes of life are likely to have developed from a plesiomorphic semi-aquatic one. A taxonomically comprehensive data set of turtle humeri was examined to ascertain if adaptation to an aquatic or a terrestrial lifestyle affects the general internal bone structure. Three-dimensional and virtual cross-sections were obtained from computed microtomography to compare humeral changes among the various lifestyles – terrestrial, semi-aquatic and aquatic – focusing on the degree of resorption of periosteal bone. Regardless of lifestyle, the humeri of the 52 turtles examined lacked a large open medullary cavity, and only one or a few small cavity(ies) or intertrabecular spaces were found near the growth centre. Semi-aquatic and aquatic turtles display the highest and lowest median values of humeral compactness, respectively, suggesting that limb-bone lightening is acquired both in highly terrestrial and in highly aquatic turtles. The broad overlap in compactness values between the lifestyles and the lack of tubular structure in all turtles, however, suggest that selection pressure of skeletal lightening in terrestrial turtles is not high enough to cause a tubular structure, possibly because of the rather passive mode of locomotion in terrestrial turtles. This overlap also suggests that the humeral compactness could not be used alone to provide an indication of lifestyle in turtles. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112, 719–734.
TL;DR: It is hypothesized that temperature is likely a major selective pressure acting on morphology across latitudes, although hypoxia or air density may be more important along elevational gradients, and the likelihood of documenting ecogeographical ‘rules’ depends on the environmental context in which temperature variation is examined.
Abstract: Consistent responses by various organisms to common environmental pressures represent strong evidence of natural selection driving geographical variation. According to Bergmann's and Allen's rules, animals from colder habitats are larger and have smaller limbs than those from warmer habitats to minimize heat loss. Although evidence supporting both rules in different organisms exists, most studies have considered only elevational or latitudinal temperature gradients. We tested for the effects of temperature associated with both elevation and latitude on body and appendage size of torrent ducks (Merganetta armata), a widespread species in Andean rivers. We found a negative relationship between body size and temperature across latitude consistent with Bergmann's rule, whereas there was a positive relationship between these variables along replicate elevational gradients at different latitudes. Limb-size variation did not support Allen's rule along latitude, nor along elevation. High-elevation ducks were smaller and had longer wings than those inhabiting lower elevations within a river. We hypothesize that temperature is likely a major selective pressure acting on morphology across latitudes, although hypoxia or air density may be more important along elevational gradients. We conclude that the effect of temperature on morphology, and hence the likelihood of documenting ecogeographical ‘rules’, depends on the environmental context in which temperature variation is examined. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 850–862.
TL;DR: This work studied the association between Philodendron adamantinum, a species endemic to the Espinhaco Range in Minas Gerais, South-East Brazil, and its exclusive pollinators, and analysed its floral scent composition, and performed field bioassays to verify the scent-mediated attraction of pollinators.
Abstract: Cyclocephline scarabs and their host plants are documented as highly specialized plant–pollinator associations, with various fine-tuned adaptations. We studied the association between Philodendron adamantinum, a species endemic to the Espinhaco Range in Minas Gerais, South-East Brazil, and its exclusive pollinators. We focused on the pollination mechanism and reproductive success of P. adamantinum, analysed its floral scent composition, and performed field bioassays to verify the scent-mediated attraction of pollinators. The reproductive success of P. adamantinum depends on the presence of Erioscelis emarginata (Scarabaeidae, Cyclocephalini), its sole pollinator. At dusk, the inflorescences heat up to 18 °C above the surrounding ambient air temperature and give off a strong sweet odour, from which 32 volatile compounds were isolated. Dihydro-β-ionone, the major constituent in the floral scent bouquet, lures individuals of E. emarginata when applied to scented artificial decoys, either alone or blended with methyl jasmonate. We attribute the low fruit set of P. adamantinum at our study sites to pollinator limitation of small and isolated populations and geitonogamic pollen flow of vegetatively generated clonal plant groups. The interaction between P. adamantinum and E. emarginata shows common traits typical of the known plant–pollinator associations involving cyclocephaline scarabs: the asymmetrical dependence of plants on their pollinators, and the scent-mediated interaction between flowers and beetles. In addition to updating the current catalogue of active compounds of cantharophilous pollination systems, further experimental studies should elucidate the role of the specific chemical compounds that attract pollinators along different time and biogeographic scales. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 679–691.
TL;DR: Evidence is provided for the interplay among distinct selective pressures, from multiple-predator taxa, acting on the divergence in protective coloration of prey species in populations where relatively cryptic green morphs have evolved.
Abstract: Evolutionary divergence in the coloration of toxic prey is expected when geographic variation in predator composition and behavior favours shifts in prey conspicuousness. A fundamental prediction of predator-driven colour divergence is that the local coloration should experience lower predation risk than novel prey phenotypes. The dorsal coloration of the granular poison frog varies gradually from populations of conspicuous bright red frogs to populations of dull green and relatively cryptic frogs. We conducted experiments with clay models in four populations to examine the geographic patterns of taxon-specific predation. Birds avoided the local phenotype while lizards consistently selected for decreased conspicuousness and crab predation did not depend on frog coloration. Importantly, birds and lizards favoured low conspicuousness in populations where relatively cryptic green morphs have evolved. This study provides evidence for the interplay among distinct selective pressures, from multiple-predator taxa, acting on the divergence in protective coloration of prey species.(c) 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113, 580-589.
TL;DR: This study highlights the relevance of considering potential ecological interactions between similarly ecological species when assessing species distributions, with Plecotus auritus/begognae occurring in Mediterranean areas, and Myotis mystacinus/alcathoe in Iberia.
Abstract: To determine what shapes the distributions of cryptic species, we aimed to unravel ecological niches and geographical distributions of three cryptic bat species complexes in Iberia, Plecotus auritus/begognae, Myotis mystacinus/alcathoe and Eptesicus serotinus/isabellinus (with 44, 69, 66, 27, 121 and 216 records, respectively), considering ecological interactions and biogeographical patterns. Species distribution models (SDMs) were built using a presence-only technique (Maxent), incorporating genetically identified species records with environmental variables (climate, habitat, topography). The most relevant variables for each species’ distribution and respective response curves were then determined. SDMs for each species were overlapped to assess the contact zones within each complex. Niche analyses were performed using niche metrics and spatial principal component analyses to study niche overlap and breadth. The Plecotus complex showed a parapatric distribution, although having similar biogeographical affinities (Eurosiberian), possibly explained by competitive exclusion. The Myotis complex also showed Eurosiberian affinities, with high overlap between niches and distribution, suggesting resource partitioning between species. Finally, E. serotinus was associated with Eurosiberian areas, while E. isabellinus occurred in Mediterranean areas, suggesting possible competition in their restricted contact zone. This study highlights the relevance of considering potential ecological interactions between similarly ecological species when assessing species distributions. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112,150–162.
TL;DR: In this article, the effects of genetic introgression of aquaculture stocks in local forms is well documented in many fish species but their evolutionary consequences for the local populations have not been thoroughly explored.
Abstract: Genetic introgression of aquaculture stocks in local forms is well documented in many fish species but their evolutionary consequences for the local populations have not been thoroughly explored. Due to its wide geographical range, the existence of many locally adapted forms and the frequent occurrence of introgression of aquaculture stocks in local forms, brown trout represents the ideal system to study the effects of such introgressions. Here, we focus on a group of rivers and streams in Sicily (Italy), and, by using molecular tools, we show that autochthonous populations are probably derived from the Southern Atlantic clade, which is present in the Iberian peninsula and North Africa. Three out of the four studied rivers reveal signs of genetic introgression of domestic stocks. Finally, by using advanced geometric morphometric analyses, we show that genetic introgression produces a higher degree of morphological variability relative to that observed in non-introgressed populations. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112, 387–398. ADDITIONAL KEYWORDS: disparity – geometric morphometrics – human-induced evolution – LDH-C1* – Salmo cettii – Salmo trutta.
TL;DR: Conclusions reached by Xiao and colleagues are not well supported and their paradigm for fitting allometric equations is unreliable, and future investigations of allometric variation should adopt a more holistic approach and incorporate graphical validation on the original arithmetic scale.
Abstract: Xiao and colleagues re-examined 471 datasets from the literature in a major study comparing two common procedures for fitting the allometric equation y = axb to bivariate data (Xiao et al., 2011). One of the procedures was the traditional allometric method, whereby the model for a straight line fitted to logarithmic transformations of the original data is back-transformed to form a two-parameter power function with multiplicative, lognormal, heteroscedastic error on the arithmetic scale. The other procedure was standard nonlinear regression, whereby a two-parameter power function with additive, normal, homoscedastic error is fitted directly to untransformed data by nonlinear least squares. Xiao and colleagues articulated a simple (but explicit) protocol for fitting and comparing the alternative models, and then used the protocol to examine each of the datasets in their compilation. The traditional method was said to provide a better fit in 69% of the cases and an equivalent fit in another 15%, so the investigation appeared to validate findings from a large majority of prior studies on allometric variation. However, focus for the investigation by Xiao and colleagues was overly narrow, and statistical models apparently were not validated graphically in the scale of measurement. The present study re-examined a subset of the cases using a larger pool of candidate models and graphical validation, and discovered complexities that were overlooked in their investigation. Some datasets that appeared to be described better by the traditional method actually were unsuited for use in an allometric analysis, whereas other datasets were not described adequately by a two-parameter power function, regardless of how the model was fitted. Thus, conclusions reached by Xiao and colleagues are not well supported and their paradigm for fitting allometric equations is unreliable. Future investigations of allometric variation should adopt a more holistic approach and incorporate graphical validation on the original arithmetic scale. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113, 1167–1178.
TL;DR: A mechanism of evolution that ensures adaptive changes without the obligatory role of natural selection is described, according to this mechanism, the first event is a plastic adaptive change (change of phenotype), followed by stochastic genetic change which makes the transformation irreversible.
Abstract: A mechanism of evolution that ensures adaptive changes without the obligatory role of natural selection is described. According to this mechanism, the first event is a plastic adaptive change (change of phenotype), followed by stochastic genetic change which makes the transformation irreversible. This mechanism is similar to the organic selection mechanism as proposed by Baldwin, Lloyd Morgan and Osborn in the 1890s and later developed by Waddington, but considerably updated according to contemporary knowledge to demonstrate its independence from natural selection. Conversely, in the neo-Darwinian mechanism, the first event is random genetic change, followed by a new phenotype and natural selection or differential reproduction of genotypes. Due to the role of semiosis in the decisive first step of the mechanism described here (the ontogenic adaptation, or rearrangement of gene expression patterns and profile), it could be called a semiotic mechanism of evolution. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112, 287–294.
TL;DR: This study shows that hind wing shape in D. v. virgifera can be used to differentiate populations based on edaphic factors and may have application as a monitoring tool in the integrated management of the pest in particular regions of Croatia.
Abstract: The western corn rootworm Diabrotica virgifera virgifera LeConte is a pest of maize in the USA and Europe and especially a problem in particular regions of Croatia. In this study patterns of variation in hind wing shape were examined through two objectives. The first objective examined the influence of soil type on 10 populations of D. v. virgifera sampled from three regions in Croatia that differed according to edaphic factors and climate. The second objective investigated the potential evolutionary presence of directional asymmetry on hind wings. Geometric morphometrics was used to examine these objectives by quantifying the morphological variation within and among individuals and populations. Overall, D. v. virgifera hind wing shape changed according to major soil type classifications in Croatia. The three hind wing morphotypes found varied because of basal radial vein differences, related to landmarks 1, 3, 7 and 14. This study shows that hind wing shape in D. v. virgifera can be used to differentiate populations based on edaphic factors and may have application as a monitoring tool in the integrated management of D. v. virgifera . In an evolutionary context, the presence of directional asymmetry in the hind wings of D. v. virgifera adds to the ever growing data on the evolution of insect wings.
TL;DR: The results show a complex array of spatial patterns in plant defence that match the distribution and foraging behaviour of large mammals, and may help to unify the understanding of how megaherbivores have shaped the evolution of plant form and function.
Abstract: Field surveys were conducted to test whether plants deploy structural defences in ways that match the distribution of megaherbivores. In Western Australian scrublands, where adult plants are within the reach of megaherbivores, structural defences increased vertically and were deployed preferentially by adult plants. Conversely, in woodlands of Eastern Australia and California, where adult plants grow above the reach of megaherbivores, structural defences decreased vertically. Populations of closely-related taxa on offshore islands exhibited significant reductions in defence in the absence of megaherbivores. The results also demonstrate that island plant taxa can evolve vertical changes in defence after colonizing continents, where they are exposed to megaherbivores. Overall, the results of the present study illustrate a complex array of spatial patterns in plant defence that match the distribution and foraging behaviour of large mammals. When interpreted alongside previous work demonstrating similar spatial patterns in other types of plant defence, the results may help to unify our understanding of how megaherbivores have shaped the evolution of plant form and function. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 38–48.
TL;DR: A review of previously published as well as unpublished data of shell microstructures of these groups and those of some of the earliest aquatic turtles from the Middle Jurassic show that bones are strongly influenced functionally as a result of life spent in an aquatic medium, whereas there are little to no characters of systematic value in the bones.
Abstract: Modern turtles exhibit a broad scope of ecological adaptations, including coastal marine and pelagic habitats, and, during their evolutionary history, turtles repeatedly exploited the aquatic environment as well. Although some pleurodiran clades also ventured into the marine realm, it is the cryptodires that did so most extensively. Among those, three major radiation phases are distinguished, with the first phase consisting of basal eucryptodiran taxa inhabiting littoral or near costal environments (Late Jurassic, Europe); the second phase including more open marine chelonioids (starting in the late Early Cretaceous, mainly North America and Eurasia); and the third phase (starting in the Palaeocene/Eocene, global distribution) including the highly-nested chelonioids, such as the modern cheloniid and dermochelyid turtles and closest relatives. A review of previously published as well as unpublished data of shell microstructures of these groups and those of some of the earliest aquatic turtles from the Middle Jurassic, Heckerochelys romani and Eileanchelys waldmani, show that bones are strongly influenced functionally as a result of life spent in an aquatic medium, whereas there are little to no characters of systematic value in the bones. We confirm the general tetrapod pattern that pelagic forms tend to show osteoporotic-like shell structures and neritic forms tend to have more bone ballast, especially by retaining a thickened external compacta. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112, 701–718.
TL;DR: In the present study, two WCM genotypes of divergent host specificity and one DBM genotype were tested for the acceptance of Poaceae, Amarylidaceae, and Liliaceae species that were reported or suspected as hosts of WCM or DBM.
Abstract: Two economically important eriophyoid mites, Aceria tosichella (wheat curl mite; WCM) and Aceria tulipae (dry bulb mite; DBM), were frequently confounded in the world literature until the late 20th Century. Their morphological similarity and ambiguous data from plant-transfer and virus-transmission trials contributed to this confusion. Until recently, there was a general lack of knowledge about the existence of species complexes and it was not possible to accurately genotype tested mites. In the present study, two WCM genotypes of divergent host specificity (MT-1 and MT-2) and one DBM genotype were tested for the acceptance of Poaceae, Amarylidaceae, and Liliaceae species that were reported or suspected as hosts of WCM or DBM. The MT-1 lineage colonized all tested plants. Onion- and garlic-associated DBM populations did not colonize tulip and wild garlic, suggesting that host-acceptance variability exists within A. tulipae s.l. Morphometric analysis did not discriminate closely-related MT-1 and MT-2 genotypes but completely separated both WCM genotypes from DBM based on the larger overall body size of the latter. Three morphological traits combined to discriminate between the DBM and MT-1 genotypes, both of which can infest Amarylidaceae bulbs. In total, these combined DNA sequence, host-acceptance, morphometrical results unambiguously separated two WCM and one DBM genotypes. Similar studies on additional lineages of both WCM and DBM should ultimately dispel previous taxonomic confusion between these two species. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 421–436.
TL;DR: Analysis of the cytochrome b and NADH dehydrogenase subunit 3 genes of introduced and native Pelophylax from Switzerland revealed the occurrence of several genetic lineages of invasive frogs in western Switzerland, and showed that several populations of the native pool frog (P. lessonae) cluster with the Italian pool frog P. bergeri, meaning that the number of native P. lessonsae populations is less important than expected in Switzerland.
Abstract: The marsh frog (Pelophylax ridibundus) has been introduced in many places of Central and Western Europe due to commercial trades with Eastern Europe, and is rapidly replacing the native pool frog (P. lessonae). A large number of Pelophylax species are distributed in Eastern Europe and the strong phenotypic similarity between these species is rendering their identification hazardous. Consequently, alien populations of Pelophylax might not strictly be composed of P. ridibundus as previously suspected. In the present study, we analyzed the cytochrome b and NADH dehydrogenase subunit 3 genes of introduced and native Pelophylax from Switzerland (299 individuals), in order to properly identify the source populations of the invaders and the genetic status of the native species. Our study highlighted the occurrence of several genetic lineages of invasive frogs in western Switzerland. Unexpectedly, we also showed that several populations of the native pool frog (P. lessonae) cluster with the Italian pool frog P. bergeri from central Italy (considered by some authors as a subspecies of P. lessonae) Hence, these populations are probably also the result of introductions, meaning that the number of native P. lessonae populations is less important than expected in Switzerland. These findings have important implications concerning the conservation of the endemic pool frog populations, as the presence of multiple alien species could strongly affect their long-term subsistence.
TL;DR: It is demonstrated that natural levels of polymorphic variation can impede the efficiency of visually orientated predators and increase survival of prey, and this protective effect supports the limited attention hypothesis.
Abstract: Polymorphism, the coexistence of two or more variants within a population, has served as a classic model system to address questions about the evolution and maintenance of intraspecific variation. It has been hypothesized that a natural level of colour polymorphism may impair the search efficiency of visually orientated predators. To test this polymorphism protects hypothesis, we asked human participants to search for images of natural black, striped or grey Tetrix subulata grasshopper colour morphs presented against photographs of their natural habitat on computer screens. Fewer grasshoppers were detected when morphs were presented in mixed than in uniform sequences. All three morphs benefited to comparable degrees, in terms of reduced detection, from being presented in polymorphic sequences. Our findings demonstrate that natural levels of polymorphic variation can impede the efficiency of visually orientated predators and increase survival of prey. This protective effect supports the limited attention hypothesis, explains why predators develop ‘search images’, may account for the spread and establishment of novel colour variants, and contributes to maintenance of polymorphisms. © 2014 The Authors. Biological Journal of the Linnean Society published by John Wiley & Sons Ltd on behalf of The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112, 546–555.
TL;DR: The results of the present study are consistent with Pleistocene survival of S. miyabeanum in unglaciated Beringia, although the authors cannot eliminate the possibility that the species recolonized Alaska from Asia more recently.
Abstract: Unlike seed plants where global biogeographical patterns typically involve interspecific phylogenetic history, spore-producing bryophyte species often have intercontinental distributions that are best understood from a population genetic perspective. We sought to understand how reproductive processes, especially dispersal, have contributed to the intercontinental ‘Pacific Rim’ distribution of Sphagnum miyabeanum. In total, 295 gametophyte plants from western North America (California, Oregon, British Columbia, Alaska), Russia, Japan, and China were genotyped at 12 microsatellite loci. Nucleotide sequences were obtained for seven anonymous nuclear loci plus two plastid regions from 21 plants of S. miyabeanum and two outgroup species. We detected weak but significant genetic differentiation among plants from China, Japan, Alaska, British Columbia, and the western USA. Alaskan plants are genetically most similar to Asian plants, and British Columbian plants are most similar to those in the western USA. There is detectable migration between regions, with especially high levels between Alaska and Asia (China and Japan). Migration appears to be recent and/or ongoing, and more or less equivalent in both directions. There is weak (but significant) isolation-by-distance within geographical regions, and the slope of the regression of genetic on geographical distance differs for Asian versus North American plants. A distinctive Vancouver Island morphotype is very weakly differentiated, and does not appear to be reproductively isolated from plants of the normal morphotype. The intercontinental geographical range of S. miyabeanum reflects recent and probably ongoing migration, facilitated by the production of tiny spores capable of effective long distance dispersal. The results of the present study are consistent with Pleistocene survival of S. miyabeanum in unglaciated Beringia, although we cannot eliminate the possibility that the species recolonized Alaska from Asia more recently. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 17–37.
TL;DR: The results indicate that the evolution of large brain size in birds was driven by several important selective pressures, including selective pressures of procuring extra-pair copulations whilst maintaining a social partnership.
Abstract: There are several hypotheses suggesting that social complexity, including pair bonding, is important in the evolution of increased brain size. I examined whether genetic or social monogamy was related to large brain size in birds. Recent work has indicated that the length and strength of pair bonds are associated with large brain size. I tested several hypotheses for the evolution of large brain size in 42 species of bird by including life history variables in a regression model. A test on 100 phylogenetic trees revealed no phylogenetic signal in brain size. Controlling for body size, a principal components analysis was run on the life history variables and degrees of extra-pair paternity. The main principal component (PC1) was regressed on brain size revealing a strong, positive association. Social, but not genetic, monogamy was positively related to brain size. Large brain size is related to the selective pressures of procuring extra-pair copulations whilst maintaining a social partnership. However, other life history variables also loaded positively and significantly on brain size. These results indicate that the evolution of large brain size in birds was driven by several important selective pressures. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, , ••‐••.
TL;DR: The article focuses on the active role of the organism in the subsequent evolution of its descendants, and choice, control of the environment, adaptability, and mobility all play their part.
Abstract: The article focuses on the active role of the organism in the subsequent evolution of its descendants Choice, control of the environment, adaptability, and mobility all play their part This growth area in biology and other active centres of research on epigenetics and different forms of inheritance are re-invigorating evolutionary biology Many evolutionary biologists have taken the view that an understanding of development is irrelevant to theories of evolution However, the integration of several disciplines now suggests that the orthodoxy is misplaced © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 112, 268–275