Showing papers in "Biological Journal of The Linnean Society in 2013"
TL;DR: It is found that snout–vent lengths predict masses better than total lengths and microhabitat preferences profoundly influence body shape: arboreal snakes are lighter than terrestrial snakes, whereas aquatic snakes are heavier than terrestrial snake of a similar length.
Abstract: Body size and body shape are tightly related to an animal's physiology, ecology and life history, and, as such, play a major role in understanding ecological and evolutionary phenomena. Because organisms have different shapes, only a uniform proxy of size, such as mass, may be suitable for comparisons between taxa. Unfortunately, snake masses are rarely reported in the literature. On the basis of 423 species of snakes in 10 families, we developed clade-specific equations for the estimation of snake masses from snout–vent lengths and total lengths. We found that snout–vent lengths predict masses better than total lengths. By examining the effects of phylogeny, as well as ecological and life history traits on the relationship between mass and length, we found that viviparous species are heavier than oviparous species, and diurnal species are heavier than nocturnal species. Furthermore, microhabitat preferences profoundly influence body shape: arboreal snakes are lighter than terrestrial snakes, whereas aquatic snakes are heavier than terrestrial snakes of a similar length. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ●●, ●●–●●.
85 citations
TL;DR: It is revealed that A. tosichella is not a homogeneous species comprising polyphagous panmictic populations rather it is a complex of genetically distinct lineages with variable host ranges and therefore variable pest potential.
Abstract: Aceria tosichella (the wheat curl mite, WCM) is a global pest of wheat and other cereals, causing losses by direct damage, as well as the transmission of plant viruses. The mite is considered to have an unusually wide host range for an eriophyoid species. The present study tested the commonly held assumption that WCM is a single, highly polyphagous species by assessing the host range of genetically distinct lineages of WCM occurring in Poland on different host plants. Genotyping was performed by analyzing nucleotide sequence data from fragments of the mitochondrial cytochrome c oxidase subunit I (COI) and the nuclear D2 region of 28S rDNA. Mean between-lineage distance estimated using COI data was found to be one order of magnitude greater than the within-clade lineage and, in some cases, comparable to distances between WCM lineages and a congeneric outgroup species. Host acceptance was tested by quantifying population growth for different WCM mitochondrial (mt)DNA lineages when transferred from source host plants to test plants. These experiments revealed significant differences in host colonization ability between mtDNA lineages, ranging from highly polyphagous to more host-specific. The present study reveals that WCM is composed of several discrete genetic lineages with divergent host-acceptance and specificity traits. Genetic variation for host acceptance within A. tosichella s.l. may act as a reproductive barrier between these lineages, most of which had narrow host ranges. Two lineages appear to have high pest potential on cereals, whereas several others appear to specialize on wild grass species. We conclude that WCM is not a homogeneous species comprising polyphagous panmictic populations rather it is a complex of genetically distinct lineages with variable host ranges and therefore variable pest potential. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 165–180. ADDITIONAL KEYWORDS: 28S rDNA D2 – DNA barcoding – acceptance – specificity – mtDNA COI – species complex.
71 citations
TL;DR: Tube length showed a strong positive relationship with nectar volume, which implies that plants with long corolla tubes are under selection to offer relatively large amounts of nectar to entice visits by polyphagous long-tongued hawkmoths.
Abstract: Hawkmoths (Lepidoptera, Sphingidae) are considered important pollinators in tropical regions, but the frequency and degree of reciprocal specialization of interactions between hawkmoths and flowers remain poorly understood. Detailed observations at two sites in Kenya over a two-year period indicate that adult hawkmoths are routinely polyphagous and opportunistic, regardless of their proboscis length. About 700 individuals of 13 hawkmoth species were observed visiting a wide range of plant species at the study sites, including 25 taxa that appear to be specifically adapted for pollination by hawkmoths. We estimate that 277 plant species in Kenya (c. 4.61% of the total angiosperm flora) are adapted for pollination by hawkmoths. Floral tube lengths of these plants have a bimodal distribution, reflecting the existence of two hawkmoth guilds differing in tongue length. Hawkmoths exhibited strongly crepuscular foraging patterns with activity confined to a 20-min period at dusk and, in some cases, a similar period just before dawn. Corolla tube length appears to act as a mechanical filter as the longest-tubed plants were visited by the fewest hawkmoth species and these were exclusively from the long-tongued guild. Tube length showed a strong positive relationship with nectar volume, even after phylogenetic correction, which implies that plants with long corolla tubes are under selection to offer relatively large amounts of nectar to entice visits by polyphagous long-tongued hawkmoths. Our study shows that diffusely co-evolved pollination systems involving long-tongued hawkmoths are clearly asymmetrical, with plants exhibiting a high degree of floral specialization, while hawkmoths exhibit polyphagous behaviour. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 199–213.
69 citations
TL;DR: A scenario is proposed where climate-driven processes may have played a primary role in the differentiation among phylogroups and six well-supported phylog groups, differentiated during the Pleistocene were evidenced.
Abstract: In order to evaluate the contribution of geological, environmental, and climatic changes to the spatial distribution of genetic variation of Mastomys natalensis, we analysed cytochrome b sequences from the whole distribution area of the species to infer its phylogeographic structure and historical demography. Six well-supported phylogroups, differentiated during the Pleistocene, were evidenced. No significant correlation between genetic and geographic distances was found at the continental scale, and the geographic distributions of the observed phylogroups have resulted from extensive periods of isolation caused by the presence of putative geographic and ecological barriers. The diversification events were probably influenced by habitat contraction/expansion cycles that may have complemented topographic barriers to induce genetic drift and lineage sorting.According to our results, we propose a scenario where climate-driven processes may have played a primary role in the differentiation among phylogroups.
67 citations
TL;DR: The data suggest that female lizards of many species are under fecundity selection to increase abdomen size, consequently enhancing their reproductive output (enlarging either clutch or offspring size) and that male lizards are under sexual selection to increasing head size, which is positively related to winning male–male combats and to faster grasping of females.
Abstract: Sexual-size dimorphism (SSD) is widespread in animals. Body length is the most common trait used in the study of SSD in reptiles. However, body length combines lengths of different body parts, notably heads and abdomens. Focusing on body length ignores possible differential selection pressures on such body parts. We collected the head and abdomen lengths of 610 lizard species (Reptilia: Squamata: Sauria). Across species, males have relatively larger heads, whereas females have relatively larger abdomens. This consistent difference points to body length being an imperfect measure of lizard SSD because it comprises both abdomen and head lengths, which often differ between the sexes. We infer that female lizards of many species are under fecundity selection to increase abdomen size, consequently enhancing their reproductive output (enlarging either clutch or offspring size). In support of this, abdomens of lizards laying large clutches are longer than those of lizards with small clutches. In some analyses, viviparous lizards have longer abdomens than oviparous lizards with similar head lengths. Our data also suggest that male lizards are under sexual selection to increase head size, which is positively related to winning male–male combats and to faster grasping of females. Thus, larger heads could translate into higher probability to mate. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 665–673.
66 citations
TL;DR: The femoral microanatomy of 155 species of extant amniotes of known lifestyle is studied to demonstrate a possible link between some basic parameters of bone structure and specific lifestyles, as well as phylogenetic relationships between taxa.
Abstract: The femoral microanatomy of 155 species of extant amniotes (57 species of mammals, 15 species of turtles, 56 species of lepidosaurs, and 27 species of birds) of known lifestyle is studied to demonstrate a possible link between some basic parameters of bone structure and specific lifestyles, as well as phylogenetic relationships between taxa. Squared change parsimony with random taxon reshuffling and pairwise comparisons reveal that most compactness and size parameters exhibit both phylogenetic and ecological signals. A discriminant analysis produces several inference models, including a ternary model (aquatic, amphibious, terrestrial) that yield the correct lifestyle in 88% of the cases. These models are used to infer the lifestyle of three extinct Permian temnospondyls: Eryops megacephalus, Acheloma dunni, and Trimerorhachis insignis. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 644–655.
63 citations
TL;DR: This study integrates two methods to regionalize North America, using species distribution models of mammals: endemicity analysis (EA) and parsimony analysis of endemicity (PAE), and shows that North America is probably more complex than previously assumed.
Abstract: Since the 19th Century, two regions have been recognized for North American mammals, which overlap in Mexico. The Nearctic region corresponds to the northern areas and the Neotropical region corresponds to the southern ones. There are no recent regionalizations for these regions under the criterion of endemism. In the present study, we integrate two methods to regionalize North America, using species distribution models of mammals: endemicity analysis (EA) and parsimony analysis of endemicity (PAE). EA was used to obtain areas of endemism and PAE was used to hierarchize them. We found 76 consensus areas from 329 sets classified in 146 cladograms, and the strict consensus cladogram shows a basal polytomy with 14 areas and 16 clades. The final regionalization recognizes two regions (Nearctic and Neotropical) and a transition zone (Mexican Transition Zone), six subregions (Canadian, Alleghanian, Californian-Rocky Mountain, Pacific Central America, Mexican Gulf-Central America, and Central America), two dominions (Californian and Rocky Mountain), and 23 provinces. Our analysis show that North America is probably more complex than previously assumed. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 485–499.
62 citations
TL;DR: It is shown that much remains to be done to better understand the relationship between histological features, growth rate and metabolism in extant taxa in order to make inferences in the fossil groups.
Abstract: Aquatic reptiles are very diversified in the fossil record The description and pooling of certain bone histological features (collagenous weave and vascular network) of the various groups of aquatic reptiles highlight what this histological information can tell us about the process of secondary adaptation to an aquatic life Notably, they show the absence of interaction between these histological features on the one hand and body size, mode of swimming, type of microanatomical specialization and phylogeny on the other These histological features in aquatic reptiles seem to essentially provide information about the growth rate and basal metabolic rate of these taxa The growth rate seems to have been rather high in most marine reptiles, when compared with terrestrial ectotherms Moreover, distinct metabolic abilities are suggested Indeed, various groups probably displayed a peculiarly high body temperature, and some show trends towards endothermy This study also emphasizes the crucial need for homologous comparisons in histology and shows that much remains to be done to better understand the relationship between histological features, growth rate and metabolism in extant taxa in order to make inferences in the fossil groups © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ●●, ●●–●●
62 citations
TL;DR: Consistent patterns of ecomorphological convergence in these two perciform groups provide strong evidence for adaptation involving constrains in functional morphology associated with feeding.
Abstract: Despite divergent evolutionary histories, Neotropical cichlids (Cichlidae) and Nearctic sunfishes (Centrarchidae) appear to have similar functional morphotypes and occupy similar ecological niches. We applied an integrative approach analyzing morphological traits, stomach contents, and stable isotope ratios (δ13C, δ15N) to investigate whether local assemblages of cichlids (Venezuela, Peru) and centrarchids (Texas) reveal one-to-one patterns of morphological and ecological convergence. Multivariate ordinations performed on diet and morphology datasets identified a broad overlap between cichlid and centrarchid assemblages. The functional morphology of the two groups has diversified in a convergent manner within the confines of ram-suction modes of prey ingestion. Both groups had the same set of ecomorph types that corresponded to the same trophic niches, including substrate-sifting invertivores, epibenthic invertebrate gleaners, and piscivores; the one exception was a molluscivorous sunfish, comprising a niche that was not represented in the two cichlid assemblages. Estimates of trophic positions based on stable isotope analysis revealed convergent vertical trophic structure; with few exceptions, fishes with similar morphologies had similar trophic positions. Large-bodied piscivores had highest trophic positions, whereas small and medium-bodied generalists and invertivores had low to intermediate trophic positions. Consistent patterns of ecomorphological convergence in these two perciform groups provide strong evidence for adaptation involving constrains in functional morphology associated with feeding. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 146–164.
62 citations
TL;DR: Findings show that ghost crabs have a circadian rhythm of colour change mediating camouflage, which is fine-tuned by adaptation to the background brightness, which can enable individuals to achieve effective camouflage under a range of environmental conditions, substrates, and time periods.
Abstract: Species that change colour present an ideal opportunity to study the control and tuning of camouflage with regards to the background. However, most research on colour-pattern change and camouflage has been undertaken with species that rapidly alter appearance (in seconds), despite the fact that most species change appearance over longer time periods (e.g. minutes, hours, or days). We investigated whether individuals of the horned ghost crab (Ocypode ceratophthalmus) from Singapore can change colour, when this occurs, and how it influences camouflage. Individuals showed a clear daily rhythm of colour change, becoming lighter during the day and darker at night, and this significantly improved their camouflage to the sand substrate upon which they live. Individuals did not change colour when put into dark conditions, but they did become brighter when placed on a white versus a black substrate. Our findings show that ghost crabs have a circadian rhythm of colour change mediating camouflage, which is fine-tuned by adaptation to the background brightness. These types of colour change can enable individuals to achieve effective camouflage under a range of environmental conditions, substrates, and time periods, and may be widespread in other species. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 257–270.
60 citations
TL;DR: The phylogenetic analyses suggest that the oriental green lizards of the Lacerta trilineata group is in need of a taxonomical revision because the identified lineages and genetic diversity are not congruent with the currently recognized subspecies.
Abstract: The oriental green lizards of the Lacerta trilineata group are widely distributed in Greece, Anatolia, the eastern Mediterranean, the southern Caucasus, and the Zagros mountains in Iran. We studied their phylogeography using three mitochondrial markers with comprehensive sampling from most representatives of the group. Their phylogeny and divergence times (implementing fossil-based molecular clock calibrations) were inferred using Bayesian methods, and haplotype networks were reconstructed to assess how genetic diversity and current distributional patterns were shaped. According to our phylogenetic analyses, the group constitutes a well-supported monophylum containing several distinct evolutionary lineages with high haplotype diversity. Vicariance might explain the divergences within most lineages that have accumulated by range restriction and expansion of populations as a result of Quaternary climate oscillations and glacial refugia. However, niche divergence appears to be a major force promoting speciation, and large scale distributional patterns between lineages were shaped earlier by multiple, independent dispersals out of Anatolia during the Pliocene and early Pleistocene. The results of the present study also suggest that the group is in need of a taxonomical revision because the identified lineages and genetic diversity are not congruent with the currently recognized subspecies. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 398–408.
TL;DR: Multiple analytical approaches suggest that S. alata as currently described contains two cryptic species, and it is recommended the elevation of the western populations to species status.
Abstract: Modern methods for species delimitation provide biologists with the power to detect cryptic diversity in nearly any system. To illustrate the application of such methods, we collected data (21 sequence loci) from a carnivorous plant in southeastern North America and applied several recently developed methods (Gaussian clustering, Structurama, BPP, spedeSTEM). The pale pitcher plant Sarracenia alata inhabits the southeastern USA along the northern coast of the Gulf of Mexico. Sarracenia alata populations are separated by the Mississippi River and Atchafalaya Basin, a known biogeographical barrier in this region, but the cohesiveness of S. alata as currently classified has not been tested rigorously. Multiple analytical approaches (including allelic clustering and species trees methods) suggest that S. alata comprises two cryptic lineages that correspond to the eastern and western portions of the plant's distribution. That such clear genetic evidence for cryptic diversity exists within S. alata and is in conflict with other sources of data (e.g. morphology, environmental differentiation) illustrates a conundrum faced by those who investigate species boundaries: genetic data are often the first type of data to accumulate evidence of differentiation, but most existing taxonomic treatments are based on nongenetic data. Our results suggest that S. alata as currently described contains two cryptic species, and we recommend the elevation of the western populations to species status. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 737–746.
TL;DR: Strong evidence is found that the gular patch is a gland producing volatile compounds, which might be emitted while calling and suggested that reed frogs might use a complex combination of at least acoustic and chemical signals in species recognition and mate choice.
Abstract: Males of all reed frog species (Anura: Hyperoliidae) have a prominent, often colourful, gular patch on their vocal sac, which is particularly conspicuous once the vocal sac is inflated. Although the presence, shape, and form of the gular patch are well-known diagnostic characters for these frogs, its function remains unknown. By integrating biochemical and histological methods, we found strong evidence that the gular patch is a gland producing volatile compounds, which might be emitted while calling. Volatile compounds were confirmed by gas chromatography-mass spectrometry in the gular glands in 11 species of the hyperoliid genera Afrixalus, Heterixalus, Hyperolius, and Phlyctimantis. Comparing the gular gland contents of 17 specimens of four sympatric Hyperolius species yielded a large variety of 65 compounds in species-specific combinations. We suggest that reed frogs might use a complex combination of at least acoustic and chemical signals in species recognition and mate choice.(c) 2013 The Authors. Biological Journal of the Linnean Society published by John Wiley & Sons Ltd on behalf of The Linnean Society of London. (Less)
TL;DR: The MTE (and other theories pertaining to patterns of allometric variation) will benefit from greater awareness that the traditional allometric method is not well suited for fitting statistical models to data expressed in the arithmetic scale.
Abstract: The Metabolic Theory of Ecology (MTE) transformed the field of biological allometry from a discipline that is focused on description to a discipline that is focused more on formulating and testing theory. However, much of the empirical research providing essential background for the MTE – as well as research to test predictions of the theory – is based on the ‘allometric method’, which is a simple procedure for estimating the parameters in a two-parameter power function
by exponentiating the equation for a straight line fitted to logarithmic transformations of the original bivariate data. The allometric method has been in widespread use for so long that many investigators now apply the procedure mechanically and without due consideration for limitations of the approach. What has been missing from much of the contemporary research on allometric variation is exploratory analysis of untransformed data and graphical validation of the fitted model. I use two examples from the current literature: (1) to demonstrate the utility of exploratory analysis; (2) to illustrate how transformation may lead investigators to conclusions that are not supported by their data; and (3) to show how nonlinear regression may obviate the putative need to transform. The MTE (and other theories pertaining to patterns of allometric variation) will benefit from greater awareness that the traditional allometric method is not well suited for fitting statistical models to data expressed in the arithmetic scale. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 476–486.
TL;DR: It is argued that division of labour is acting to increase colony efficiency, which in turn shapes the investments made into individuals leading to short-lived workers and long-lived queens, and maintenance investments may be shaped due to the variable extrinsic risk faced by different castes.
Abstract: Eusocial Hymenoptera show a unique divergence in lifespan of queens and workers; queens belong to the longest lived insects while workers in most eusocial species have significantly shorter lives. The different phenotypes within a colony emerge through reproductive division of labour, which is a characteristic trait of eusocial animals. Division of labour as a measure of organismal complexity increases with colony size in eusocial species similar to the increase of complexity with size that has been shown for the whole range of living organisms. We show that queen and worker lifespan diverge in closely related species representing the transition from solitary to social life and show that queen and worker lifespan are correlated if colony size is taken into account: with increasing colony size the lifespan differential between queen and worker increases, whereas neither queen nor worker lifespan is associated with colony size. Additionally, the lifespan differential is better explained by colony size than by the weight differences between the castes. The divergence of phenotypes found is in line with the increasing specialization of subunits in larger organisms, which leads to increasing complexity. We argue that division of labour is acting to increase colony efficiency, which in turn shapes the investments made into individuals leading to short-lived workers and long-lived queens. Additionally, maintenance investments may be shaped due to the variable extrinsic risk faced by different castes. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 710–724.
TL;DR: It is indicated that glacial cycles have deeply influenced Amazonian biogeographical history, demonstrating a complex interaction between forest and nonforest habitats during the Pleistocene.
Abstract: Open vegetation (campinas and campinaranas) associated with white sand patches occurs in the form of islands in a forested matrix throughout the Amazon basin. Bird species restricted to these habitats have patchy distributions, although connectivity may have been influenced by past glacial cycles as a result of the substitution of forest by savanna. Because these landscape changes are a matter of debate in the history of Amazonia, we studied the diversification of Xenopipo atronitens, a white sand specialist, aiming to infer the effects of past climate changes. The split of Xenopipo atronitens from its sister species, Xenopipo uniformis, may be related to Tepuis erosion and retreat of escarpments during the Miocene, or to a dispersal event. Compared with birds from terra firme forest, X. atronitens has low genetic structure. Low levels of unidirectional gene flow were found from the Guyana Shield to adjacent areas. Demographic expansion starting approximately 25 kyr BP was detected for some populations and is probably related to the Last Glacial Maximum and subsequent climate improvement. Landscape genetic analyses indicate that the forested (terra firme) matrix acts as a barrier for the dispersal of X. atronitens. The results of the present study indicate that glacial cycles have deeply influenced Amazonian biogeographical history, demonstrating a complex interaction between forest and nonforest habitats during the Pleistocene. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 60–76.
TL;DR: Combined ecological niche modelling and molecular phylogeography revealed that Anatolian ground squirrels have been in refugia during the interglacial periods, suggesting that the classical paradigm of glacial range contraction and interGLacial range expansion for temperate species may not be as general as previously assumed.
Abstract: The present study aimed to understand how Anatolian ground squirrels, Spermophilus xanthoprymnus (Bennett, 1835), have responded to global climate changes through the Late Quaternary glacial–interglacial cycles. Accordingly, ecological niche modelling was used, together with molecular phylogeography. Using species occurrence data compiled from field observations and relevant sources and the maximum entropy machine learning algorithm in MAXENT, an ecological niche model was developed to predict the potential geographical distribution of S. xanthoprymnus under reconstructed past (the Last Interglacial, approximately 130 000–116 000 years ago and the Last Glacial Maximum, 21 000 years ago) and present (1950–2000) bioclimatic conditions. In addition, using cytochrome b mitochondrial DNA sequences deposited in GenBank and the Bayesian skyline plot in BEAST, demographic events (population fluctuations) were further assessed over the history of Anatolian ground squirrels. Combined ecological niche modelling and molecular phylogeography revealed that S. xanthoprymnus, itself also a temperate (mid-latitude) species, has responded to global climate changes through the Late Quaternary glacial– interglacial cycles in a fashion converse to that of most temperate (mid-latitude) species: its range expanded rather than contracted during the glacial periods and contracted rather than expanded during the interglacial periods. In other words, Anatolian ground squirrels have been in refugia during the interglacial periods, suggesting that the classical paradigm of glacial range contraction and interglacial range expansion for temperate species may not be as general as previously assumed. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 19–32. ADDITIONAL KEYWORDS: ecological niche modelling – expansion-contraction model – global climate changes – Last Glacial Maximum – Last Interglacial – molecular phylogeography – Spermophilus xanthoprymnus.
TL;DR: In this paper, the authors found that the likelihood of a male depositing a gelatinous copulatory plug in the second mating of a red-sided garter snake (Thamnophis sirtalis parietalis) decreased significantly after his second mating, perhaps limiting his reproductive success.
Abstract: During the spring emergence of red-sided garter snakes (Thamnophis sirtalis parietalis) in Manitoba, Canada, the operational sex ratio is strongly skewed towards males, who scramble to locate and court newly emerged females. A high frequency of multiple paternity litters suggests that the females are promiscuous; the gelatinous copulatory plugs (CPs) deposited by males may confer fitness benefits via passive mate guarding. Because precopulatory female choice is limited in large mating aggregations, sexual conflict may place a premium on preventing females from ejecting male sperm. In snakes, sperm are produced in the testes and delivered through the ductus deferens, and the CP is thought to be produced by the renal sexual segment and conveyed through the ureter. We manipulated the delivery of the two fluids separately by surgically ligating the ducts. Ureter-ligated males did not produce a CP, causing their sperm to leak out of the female’s cloaca immediately after copulation. Contrary to previous suggestions, histology revealed sperm distributed throughout the CP. Thus, the CP may function as a spermatophore: the protein matrix contains the sperm, which are liberated gradually as the plug dissolves. The likelihood of a male depositing a CP fell significantly after his second mating, perhaps limiting his reproductive success. These results challenge the hypothesis that passive mate guarding is the primary function of the CP in T. sirtalis parietalis. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 893–907.
TL;DR: The results obtained show that body mass evolution is tightly coordinated with the evolution of forelimb shape, although not equally in all elements, and that other factors, such as locomotor ecology, must be considered to fully understandforelimb evolution.
Abstract: In the majority of mammals, the limbs are positioned under the body and play an important role in gravitational support, allowing the transfer of the load and providing stability to the animal. For this reason, an animal's body mass likely has a significant effect on the shape of its limb bones. In the present study, we investigate the influence of body mass variation on the shape of the three long bones of the forelimb in a group of closely-related species of mammals: the musteloid carnivorans. We use geometric morphometric techniques to quantify forelimb shape; then estimate phylogenetic signal in the shape of each long bone; and, finally, we apply an independent contrasts approach to assess evolutionary associations between forelimb shape and body mass. The results obtained show that body mass evolution is tightly coordinated with the evolution of forelimb shape, although not equally in all elements. In particular, the humeral and radial shapes of heavier species appear better suited for load bearing and load transmission than the ulna. Nevertheless, our results also show that body mass influences only part of forelimb long bone shape and that other factors, such as locomotor ecology, must be considered to fully understand forelimb evolution. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 91–103.
TL;DR: The most comprehensive phylogenetic analysis of Paucituberculata to date is presented, finding that taxon sampling and reinterpretations of molar cusp and crest homologies played an important role in the generation of new phylogenetic hypotheses.
Abstract: The Paucituberculata is an endemic group of South American marsupials, recorded from the early Cenozoic up to the present. In this report, the most comprehensive phylogenetic analysis of Paucituberculata to date is presented. Fifty-seven terminal species were scored for 74 new and re-examined characters. Homologies of dental characters used in previous systematic studies were critically reviewed to evaluate their inclusion in the analysis. Phylogenetic results corroborated two major paucituberculatan clades, Palaeothentoidea and Caenolestoidea, and the main palaeothentoid groupings: Pichipilidae, Palaeothentidae, and Abderitidae. Taxon sampling and reinterpretations of molar cusp and crest homologies played an important role in the generation of new phylogenetic hypotheses. The main differences with respect to previous phylogenies were focused on palaeothentoid relationships: Palaeothentes boliviensis and Pilchenia lucina are not members of Palaeothentidae but instead clustered with Pilchenia intermedia and P. antiqua, forming the sister-group of a Palaeothentidae + Abderitidae clade, and Titanothentes simpsoni, previously considered a palaeothentine, is nested within the Acdestinae clade. Based on the time-calibrated phylogeny, the following stages in the paucituberculatan evolutionary history are suggested: origin of the group, in the Paleocene to early Eocene at the latest, split of Caenolestoidea and Palaeothentoidea clades during the late early to middle Eocene, evolutionary radiation of palaeothentid and abderitid lineages near the Oligocene–Eocene boundary, and decreased diversity and extinction of palaeothentoids during the middle Miocene. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 441–465.
TL;DR: A morphometric comparison of derived long-tonguedproboscis approximately twice as long as the body and short-Tongued Riodinidae is reported, which reveals the non-linear scaling relationships of an extremely long proboscis.
Abstract: An assessment of the anatomical costs of extremely long proboscid mouthparts can contribute to the understanding of the evolution of form and function in the context of insect feeding behaviour. An integrative analysis of expenses relating to an exceptionally long proboscis in butterflies includes all organs involved in fluid feeding, such as the proboscis plus its musculature, sensilla, and food canal, as well as organs for proboscis movements and the suction pump for fluid uptake. In the present study, we report a morphometric comparison of derived long-tongued (proboscis approximately twice as long as the body) and short-tongued Riodinidae (proboscis half as long as the body), which reveals the non-linear scaling relationships of an extremely long proboscis. We found no elongation of the tip region, low numbers of proboscis sensilla, short sensilla styloconica, and no increase of galeal musculature in relation to galeal volume, but a larger food canal, as well as larger head musculature in relation to the head capsule. The results indicate the relatively low extra expense on the proboscis musculature and sensilla equipment but significant anatomical costs, such as reinforced haemolymph and suction pump musculature, as well as thick cuticular proboscis walls, which are functionally related to feeding performance in species possessing an extremely long proboscis. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 291–304.
TL;DR: A reconstruction of the evolutionary history of six herptiles in Cyprus shows that the colonization history of those species in Cyprus started in the late Miocene and extended into the Pliocene and Pleistocene, with geodispersal, transmarine dispersal, and human-mediated dispersal having their share in shaping the diversification of Cypriote herptile.
Abstract: The colonization patterns of oceanic islands are often interpreted through transmarine dispersal. However, in islands with intense human activities and unclear geological history, this inference may be inappropriate. Cyprus is such an island, whose geotectonic evolution has not been clarified yet to the desired level for biogeographical reconstructions, leaving the questions of ‘how the Cypriote biota arrived’ and ‘does the dispersal have the formative role in patterns of its diversification’ unanswered. Here, we address these issues through a reconstruction of the evolutionary history of six herptiles (Ablepharus budaki, Ophisops elegans, Acanthodactylus schreiberi, Telescopus fallax, Pelophylax cf. bedriagae, and Hyla savignyi) by means of mitochondrial DNA (cytochrome b and 16S rRNA), applying a Bayesian phylogenetic, biogeographical, and chronophylogenetic analyses. The phylogeographical analyses show that the colonization history of those species in Cyprus started in the late Miocene and extended into the Pliocene and Pleistocene, with geodispersal, transmarine dispersal, and human-mediated dispersal having their share in shaping the diversification of Cypriote herptiles. The revealed patterns could be divided into three biogeographical categories: old colonizers that arrived in Cyprus during the late Miocene or early Pliocene either by a land bridge (geodispersal) which connected Cyprus with the mainland or by transmarine dispersal, younger colonizers that reached the island through transmarine dispersal from the Middle East, and new settlers that arrived through human-induced (voluntary or not) introductions. This work advances our knowledge of the biogeography of Cyprus and highlights the need to consider both geo- and transmarine dispersal when dealing with islands whose associations do not have a straightforward interpretation. © 2013 The Linnean Society of London
TL;DR: These findings demonstrate that, besides the well-known immediate consequences for host breeding success, parasites might also have serious, long-lasting effects through influencing feather quality and, ultimately, fitness of the host.
Abstract: Parasites usurp indispensable resources for birds during a moult, and this is particularly relevant for those parasites residing in host intestines. This might compromise the nutritionally demanding moult and, thus, feather functionality. Although lower feather quality has profound and multifaceted adverse effects on residual fitness, surprisingly, little is known about parasites' effect on feather traits, especially over the longer term. We conducted an aviary experiment by medicating half of a group of naturally infested house sparrows Passer domesticus against intestinal coccidians for 15 months, spanning two consecutive postnuptial moults, whereas the other half was kept infested (i.e. without medication). Coccidian infestation significantly and negatively affected the size of the uropygial gland during the second moulting period compared to the medicated group. Furthermore, wing length was significantly shorter after the second moulting in the non-medicated compared to the medicated female birds, which indicates that the negative effects of coccidians emerge only after a prolonged exposure to parasite infestation. Non-medicated birds grew poorer quality flight feathers detected in a large number of feather traits both after the first and second moults. In the case of non-medicated birds, the primaries were lighter and shorter, and had a smaller vane area, thinner rachis and decreased stiffness, although a higher barb and barbule density, which may have various consequences for fitness through reducing flight performance. Our findings demonstrate that, besides the well-known immediate consequences for host breeding success, parasites might also have serious, long-lasting effects through influencing feather quality and, ultimately, fitness of the host. © 2013 The Linnean Society of London
TL;DR: The analyses determined that rorqual mandibles exhibit positive allometry, whereby the relative size of these mandibles becomes greater with increasing body size, and robust scaling relationships allowed us to predict mandible length for fragmentary remains (e.g. incomplete and/or fossil specimens), and showed the allometry of mandibles length to body size in extant mysticetes, which hints at fundamental developmental constraints in Mysticetes despite their ecomorphological differences in feeding styles.
Abstract: Rorqual whales (crown Balaenopteridae) are unique among aquatic vertebrates in their ability to lunge feed. During a single lunge, rorquals rapidly engulf a large volume of prey-laden water at high speed, which they then filter to capture suspended prey. Engulfment biomechanics are mostly governed by the coordinated opening and closing of the mandibles at large gape angles, which differentially exposes the floor of the oral cavity to oncoming flow. The mouth area in rorquals is delimited by unfused bony mandibles that form kinetic linkages to each other and with the skull. The relative scale and morphology of these skeletal elements have profound consequences for the energetic efficiency of foraging in these gigantic predators. Here, we performed a morphometric study of rorqual mandibles using a data set derived from a survey of museum specimens. Across adult specimens of extant balaenopterids, mandibles range in size from ∼1–6 m in length, and at their upper limit they represent the single largest osteological element of any vertebrate, living or extinct. Our analyses determined that rorqual mandibles exhibit positive allometry, whereby the relative size of these mandibles becomes greater with increasing body size. These robust scaling relationships allowed us to predict mandible length for fragmentary remains (e.g. incomplete and/or fossil specimens), as we demonstrated for two partial mandibles from the latest Miocene of California, USA, and for mandibles from previously described fossil balaenopterids. Furthermore, we showed the allometry of mandible length to body size in extant mysticetes, which hints at fundamental developmental constraints in mysticetes despite their ecomorphological differences in feeding styles. Lastly, we outlined how our findings can be used to test hypotheses about the antiquity and evolution of lunge feeding. © 2012 The Linnean Society of London
TL;DR: There was congruence among the mitochondrial, nuclear, and geographical data, suggesting that the actual number of species in the continental Australian blindsnakes is at least two times the current number of recognized, nominal species.
Abstract: The worm-like snakes (Scolecophidia; approximately 400 nominal extant species) have a conservative morphology and are among the most poorly-known terrestrial vertebrates. Although molecular evidence has helped determine their higher-level relationships, such data have rarely been used to discriminate among species. We generated a molecular data set for the continental Australian blindsnakes (genus Ramphotyphlops) to determine the concordance of molecular and morphological information in the taxonomic recognition of species. Our dataset included 741 specimens morphologically attributed to 27 nominal Ramphotyphlops species. We proposed species hypotheses (SHs) after analysis of sequences from a variable mitochondrial gene (cytochrome b) and examined these SHs with additional evidence from a nuclear gene (prolactin receptor) and geographical data. Although the nuclear marker was not as fast-evolving and discriminating as the mitochondrial marker, there was congruence among the mitochondrial, nuclear, and geographical data, suggesting that the actual number of species is at least two times the current number of recognized, nominal species. Several biogeographical barriers and complex phytogeographical and geological patterns appeared to be involved in the division of some burrowing snake populations and, by consequence, in their diversification and speciation through isolation. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 427–441.
TL;DR: The results emphasize the need (if working with classical markers) to use different systems to obtain an understanding as to whether hybridization between wild and domestic relatives might have affected the genetic make-up of a local population.
Abstract: Hybridization between wild species and their domestic relatives can be an important conservation and management problem. Genetic purity of the wild species is desirable per se and the phenomenon can have unpredictable evolutionary consequences. Declining European wild boar populations were frequently restocked with farmed wild boars that sometimes had been crossed with domestic pigs. We used simple polymerase chain reaction-based diagnostic tests to detect the presence of mitochondrial DNA and coat colour alleles of domestic origin in wild boars from Belgium, Luxembourg, and western Germany. Microsatellite genotypes were used to test for genetic admixture between the wild boars and domestic pigs. Although almost one-third of all Luxembourg wild boars carried Asian mitochondrial DNA haplotypes originating from domestic pigs, microsatellite-based clustering only identified four putatively admixed individuals in Luxembourg. By contrast, clustering identified wild boar × domestic hybrids in most sampling locations in Belgium. We interpret these results as evidence of releases of hybrid captive-reared wild boars. Our results emphasize the need (if working with classical markers) to use different systems to obtain an understanding as to whether hybridization between wild and domestic relatives might have affected the genetic make-up of a local population. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 104–115.
TL;DR: The results show that the role of the uropygial gland dynamically varies during the annual cycle, potentially in response to seasonal variation in parasitic infection risk, and aquatic environments may promote the production of gland oil.
Abstract: Defence mechanisms against parasites and pathogens are some of the most elaborate biological systems in animals. The oily secretion of the avian uropygial gland has been suggested to serve as a chemical defence against feather and eggshell bacteria. Yet, the traits associated with uropygial gland oil production are not well understood. We conducted a phylogenetic analysis comprising 132 European bird species aiming to test: (1) whether life-history and ecological traits drive gland size evolution by potentially promoting microbial infestation and (2) how these traits affects change in the gland size throughout the annual cycle. We show that the size of the uropygial gland is dynamic (i.e. increasing from the nonbreeding to the breeding season, independent of sex). Furthermore, we found that the year-round size of the gland was similar between sexes and was correlated with different ecological and life-history traits promoting microbial infection throughout the annual cycle. During the breeding season, the total eggshell surface area in a clutch correlated significantly and positively with the gland size, suggesting the importance of oil in protecting eggs from microbes. Social species exhibited a larger gland size increase during the breeding season compared to nonsocials; a change that was also predicted by the total eggshell surface area. Aquatic, riparian and non-migratory species had larger glands than terrestrials and migrants, respectively. The findings of the present study suggest that aquatic environments may promote the production of gland oil, through either the need of waterproofing the plumage and/or defending it against the intensified feather degradation in these moist conditions. Finally, we found a negative effect of the incubation period on uropygial gland size, which may suggest an energetic constraint imposed by other development-connected costly activities. Our results show that the role of the uropygial gland dynamically varies during the annual cycle, potentially in response to seasonal variation in parasitic infection risk. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 110, 543-563.
TL;DR: Comparative multivariate analysis of the floral traits of T. ulei points to a beetle-pollinated aroid, although some of the observed traits of the species are not common to other taxa sharing this pollination strategy, which might be explained by the evolutionary history of the tribe Spathicarpeae and potential pollinator shifts.
Abstract: Taccarum ulei (Araceae, Spathicarpeae) is a seasonal geophytic aroid, native to north-eastern Brazil, that flowers during two months of the rainy season. Patterns of floral thermogenesis, pollination biology, and floral traits associated with pollination syndromes were studied and compared with those of other Araceae. Two species of cyclocephaline scarabs (Scarabaeidae, Cyclocephalini) were recognized as effective pollinators: Cyclocephala celata and Cyclocephala cearae. Larvae of an unidentified species of fruit fly (Melanoloma spp., Richardiidae, Diptera) were also frequently observed in inflorescences at various maturation stages, feeding on the connectives of male florets and fruits, and thus lowering the reproductive success of individual plants. Beetles were attracted by odoriferous inflorescences in the early evening of the first day of anthesis, during the female phase. The emission of attractive volatiles was coupled with intense thermogenic activity in the entire spadix, unlike other aroids in which only certain zones of the spadix heat up. Pollen release, which marks the beginning of the male phase on the subsequent evening, was not related to floral thermogenesis. Comparative multivariate analysis of the floral traits of T. ulei points to a beetle-pollinated aroid, although some of the observed traits of the species are not common to other taxa sharing this pollination strategy. Such incongruence might be explained by the evolutionary history of the tribe Spathicarpeae and potential pollinator shifts. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ••, ••–••.
TL;DR: In this paper, the authors applied phylogenetic inference to investigate whether such constraints underlie host plant choice in bees of the Annosmia-Hoplitis group (Megachilidae) and to what extent these bees have evolved specialized adaptations for pollen collection.
Abstract: Bees are extraordinarily diverse with respect to host plant choice and adaptation Recent findings suggest that bee host range might be largely governed by evolutionary constraints related to pollen digestion or flower recognition and handling In the present study, we applied phylogenetic inference to investigate whether such constraints underlie host plant choice in bees of the Annosmia-Hoplitis group (Megachilidae) and to what extent these bees have evolved specialized adaptations for pollen collection We demonstrate that most pollen specialist species exclusively exploit either Boraginaceae or Fabaceae, whereas all pollen generalists harvest pollen from both Boraginaceae and Fabaceae The counterintuitive affinity towards these two plant families, which are neither closely related nor share similar flower morphologies, demonstrates that pollen host choice is considerably constrained in this group of bees We hypothesize that this Boraginaceae-Fabaceae paradox might be the result of (1) similar secondary metabolites in the pollen of both families; (2) metabolites that can be detoxified by the same physiological tools; or (3) similar pollen nutrient composition Contrary to the widely held belief that specialized adaptations for pollen collection are rare among bees, such adaptations are common in the Annosmia-Hoplitis bees, where they have evolved several times independently to exploit flowers of widely different morphologies © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ●●, ●●–●●
TL;DR: In a critical review of 17 fossil and living clades of shell-bearing molluscs with photosymbionts (two of them newly inferred), adaptive shell modifications and ecological aspects are discussed in the broader context of Photosymbioses in other phyla.
Abstract: Partnerships between animals and photosynthesizing microbes have evolved repeatedly, although their history, adaptations, and ecology remain controversial and little understood. In a critical review of 17 fossil and living clades of shell-bearing molluscs with photosymbionts (two of them newly inferred), adaptive shell modifications and ecological aspects are discussed in the broader context of photosymbioses in other phyla. Fossil candidates have characteristics that are rare or unknown in living photosymbiotic molluscs, including cementation, porous shell microstructure, and epifaunal habits on carbonate muds. Many ancient photosymbioses may have lived in planktonically more productive environments than are typical of living tropical forms. This may be related to the late appearance (Early Eocene) of the dinoflagellate Symbiodinium, which can thrive under highly oligotrophic conditions. Living photosymbiotic molluscs represent a small and atypical sample of all the photosymbiotic clades that have evolved. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 497–511.