Variable Selection and the Coexistence of Multiple mimetic forms of the Butterfly Heliconius numata

Polymorphism in aposematic animals and coexistence of multiple mimicry rings within a habitat are not predicted by classical Müllerian mimicry. The butterfly Heliconius numata Cramer (Lepidoptera: Nymphalidae; Heliconiinae) is both polymorphic and aposematic. The polymorphism is due to variation at a single locus (or `supergene') which determines colour patterns involved in Müllerian mimicry. We sampled 11 sites in a small area (approx. 60×30km) of North-eastern Peru for H. numata and its co-mimics in the genus Melinaea and Athyrtis (Ithomiinae), and examined the role of temporal and spatial heterogeneity in the maintenance of polymorphism. Colour-patterns of Melinaea communities, which constitute the likely `mimetic environment' for H. numata, are differentiated on a more local scale than morphs of H. numata, but the latter do show a strong and significant response to local selection for colour-pattern. In contrast, analysis of enzyme polymorphism in H. numata across the region revealed no spatial structure, which is consistent with a high mobility of this species. Differences in spatial variability in the two taxa may have caused H. numata to become polymorphic, while temporal variability, not significant in this study, probably has a lesser effect. The mimetic polymorphism is therefore explained by means of multiple selection-migration clines at a single locus, a similar process to that which explains narrow hybrid zones between geographic races of other Heliconius butterflies. This revised version was published online in July 2006 with corrections to the Cover Date.     

Model toxin level does not directly influence the evolution of mimicry in the salamander <Emphasis Type="Italic">Plethodon cinereus</Emphasis>

The resemblance between palatable mimics and unpalatable models in Batesian mimicry systems is tempered by many factors, including the toxicity of the model species. Model toxicity is thought to influence both the occurrence of mimicry and the evolution of mimetic phenotypes, such that mimicry is most likely to persist when models are particularly toxic. Additionally, model toxicity may influence the evolution of mimetic phenotype by allowing inaccurate mimicry to evolve through a mechanism termed ‘relaxed selection’. We tested these hypotheses in a salamander mimicry system between the model Notophthalmus viridescens and the mimic Plethodon cinereus, in which N. viridescens toxicity takes the form of tetrodotoxin. Surprisingly, though we discovered geographic variation in model toxin level, we found no support for the hypotheses that model toxicity directly influences either the occurrence of mimicry or the evolution of mimic phenotype. Instead, a link between N. viridescens size and toxicity may indirectly lead to relaxed selection in this mimicry system. Additionally, limitations of predator perception or variation in the rate of phenotypic evolution of models and mimics may account for the evolution of imperfect mimicry in this salamander species. Finally, variation in predator communities among localities or modern changes in environmental conditions may contribute to the patchy occurrence of mimicry in P. cinereus.     

Phenotype-dependent mate choice and the influence of mixed-morph lineage on the reproductive success of a polymorphic and aposematic moth

Polymorphic warning signals in aposematic organisms are puzzling because efficient predator learning should select for the most efficient warning colouration. Yet, there are many examples of polymorphic and aposematic organisms in nature. Here, we investigated whether perceived trade-offs between natural and sexual selection, combined with different degrees of morph lineage admixture, can maintain polymorphic yellow and white hindwing colouration in aposematic wood tiger moth males (Arctia plantaginis). Prior research in the system suggests that yellow males have better warning colouration against predators, whereas white male morphs have higher mating success. We performed a mating experiment where females were offered four males: two white and two yellow. One male from each colour came from (purely) monomorphic lines (i.e. including the same paternal colour for multiple generations), whereas one male from each colour were from mixed-morph (or hybrid) lineages. We then assessed whether phenotype (colour), lineage, or an interaction between the two, best affected mating success. Our results showed that although white hindwing coloured males tended to have overall better reproductive success, this was mainly due to the significantly higher mating and hatching success of mixed-morph compared to pure-line individuals. Notably, this suggests the advantage of mixed-morph lineage is limited to white individuals, while on the contrary yellow mixed lineage moths have a disadvantage, i.e. the lowest mating success. The latter also suggests a cost to reproductive success in producing the more efficient against predators yellow warning colouration, even when those individuals recently descend from a white hindwing coloured lineage. Heterozygote, or hybrid advantage, even when confined to only one morph, has been shown to promote polymorphism in some systems, therefore, our results point at the need to further examine genetic architecture and the role of mixed-morph lineages in understanding the maintenance of polymorphisms in nature.     

Diversity within the <Emphasis Type="Italic">Hygrophorus agathosmus</Emphasis> group (Basidiomycota,Agaricales) in Northern Europe

The North European species of the Hygrophorus agathosmus group in subsection Tephroleuci were studied. Three new species are identified based on morphology, ecology and sequence data. Two species are associated with Pinus spp. One of these is described here as H. suaveolens, while the other one is only known from one locality in the Nordic countries and seems to have a more South European distribution range. A closely related sister species to H. agathosmus is identified based on ITS sequence data, H. cf. agathosmus. It is confirmed to have an intercontinental distribution range and to be associated with Picea spp. probably on more acidic to neutral soil, whereas H. agathosmus s.s. has a more limited North-East European distribution range and occurs in older and rich Picea abies forests. A neotype for H. agathosmus is here selected from South Sweden. Hygrophorus agathosmus f. albus and H. agathosmus f. aureofloccosus are confirmed as forms. No genetic differences in the ITS region between specimens with grey cap colour and the two forms were observed. A key to the species in Northern Europe is provided.     

Isozyme Analysis in a Genetic Collection of Amaranths (<Emphasis Type="Italic">Amaranthus</Emphasis> L.)

In various populations of the cultivated and weedy amaranth species, the electrophoretic patterns of alcohol dehydrogenase (ADH), glutamate dehydrogenase (GDH), malate dehydrogenase (MDH), isocitrate dehydrogenase (IDH) and malic enzyme (Me) were studied. In total, 52 populations and two varieties (Cherginskii and Valentina) have been examined. Allozyme variation of this material was low. Irrespective of species affiliation, 26 populations and two varieties were monomorphic for five enzymes; a slight polymorphism of three, two, and one enzymes was revealed in three, nine, and fourteen populations, respectively. A single amaranth locus, Adh, with two alleles, Adh F and Adh S, controls amaranth ADH. Two alleles, common Gdh S and rare Gdh F, control GDH; no heterozygotes at this locus were found. The MDH pattern has two, the fast- and slow-migrating, zones of activity (I and II, respectively). Under the given electrophoresis conditions, the fast zone is diffuse, whereas slow zone is controlled by two nonallelic genes, monomorphic Mdh 1 and polymorphic Mdh 2 that includes three alleles: Mdh 2-F, Mdh 2-N, and Mdh 2-S. Low polymorphism of IDH and Me was also found, though their genetic control remains unknown.     

Adaptive loss of color polymorphism and character displacements in sympatric <Emphasis Type="Italic">Mnais</Emphasis> damselflies

A geographical survey of two Mnais damselfly species in the Kinki area of Japan showed evidence for character displacements when the two species were found in sympatry. Mnais costalis, a species that has polymorphic male mating types of orange-winged territorial and clear-winged non-territorial morphs (hereafter abbreviated to orange and clear morphs respectively) in allopatry often shifted to having monomorphic orange morphs in sympatry. The mean body size of orange morphs was consistently larger than that of clear morph in allopatry. The mean body size of the sympatric orange morphs was even larger than that of allopatric orange morphs. By contrast, Mnais pruinosa, a species that also has two morphs of large orange and small clear morphs in allopatry, shifted to having monomorphic clear morphs in sympatry. The mean body size of the sympatric clear morphs was smaller than that of allopatric clear morphs. Divergence was also detected in the preference for habitat insolation conditions between sympatric Mnais damselflies. Both species in allopatric regions prefer half-light forest habitats, while in sympatric regions they showed diversified habitat preference: M. costalis preferred sunny habitats while M. pruinosa preferred shady habitats. Multiple character displacements in signal traits and habitat preference emerged in heterogeneous forest light environments are likely to have synergistic effects on the reproductive isolation of the two species.     

A new genus of African Lasiocampidae (Lepidoptera)

The species Gastroplakaeis idakum Bethune-Baker, 1913, G. balia Tams, 1929, and G. elongata Hering, 1941 are transferred from the genus Gastroplakaeis Möschler, 1887 into the newly erected genus Weirdonia gen. n. (the type species is Gastroplakaeis idakum Bethune-Baker, 1913), and corresponding new combinations are established. New species, Weirdonia baccara sp. n. and W. hypocrita sp. n. (type locality: Democratic Republic of the Congo), W. murena sp. n. (type locality: Northern Nigeria), and W. helicea sp. n. (type locality: Gabon) are described. A new synonymy is established: Gastroplakaeis balia Tams, 1929 = Gastroplakaeis elongata Hering, 1941 syn. n. Diagnoses and distribution maps are given for all the species.     

Thermal Preference of the Bush Cricket <Emphasis Type="Italic">Isophya rizeensis</Emphasis>; Testing the Effect of Countergradient Selection

Thermal preference is one of the most crucial components of behavioral thermoregulation in ectotherms, and documenting the adaptation of thermal preference carries great importance for studying the evolution of thermal biology. However there are not many studies focusing on the adaptation of thermal preference in elevational and latitudinal gradients. Isophya rizeensis is a color polymorphic bush cricket species endemic to the mountainous region of northeastern Turkey. Populations of this species are distributed in a wide elevational range between 350 and 2300 m. In this study, we hypothesized that the thermal preference of Isophya rizeensis might follow a countergradient variation where crickets from higher altitudes have higher temperature preferences compared to crickets from lower altitudes. To test this hypothesis, thermal preference values (T _pref ) of crickets from three altitudes groups (low, middle and high) were measured with a thermal gradient experiment. Additionally, body temperatures (T _b ) and environmental temperatures (T _a ) were measured in field. Deviation values of T _b and T _a from T _pref were calculated to investigate the extent of thermoregulation. As Isophya rizeensis is color polymorphic species where morphology pattern changes from lighter to darker types with increasing altitude we also tested whether coloration has any effect on temperature excess (T _ex ) and thermoregulation. Thermal preference values did not differ significantly between three groups and also colouration does not influence the extent of thermoregulation in this species. These results indicate that there is not sufficient evidence for the existence of a countergradient selection related with thermal behavior. However, the deviation of body (D _b ) and environmental (D _a ) temperatures suggest that at higher altitudes thermoregulation might be more efficient than lower altitudes.     

Is tadpole coloration adaptive against bird predation?

Birds are visually oriented predators, and some are known or supposed to prey upon tadpoles. Neotropical tadpoles exhibit several colorations that could potentially improve survivorship through camouflage, aposematism, or mimetism. In this study, we tested tadpoles of two hylid species for protective effects of their colorations, one potentially aposematic (Bokermannohyla martinsi) and another (Ololygon machadoi) previously hypothesized as disruptive and/or mimetic to a naucorid insect (Limnocoris porphyros). We conducted in situ and ex situ experiments and observed that the uniformly black B. martinsi tadpoles were more intensely preyed upon by birds than those of O. machadoi, regardless of background color, which may have happened because the disruptive coloration of O. machadoi hampered its detection. Alternatively, the duration of the experiments may have been too short for birds to learn about a possible toxicity of B. martinsi tadpoles, which are more active and thus more visible. Birds that had a previous experience with L. porphyros tended to attack tadpoles of O. machadoi less than naive birds. On the other hand, we did not observe any change in predation levels upon B. martinsi tadpoles whether presented to birds before or after L. porphyros. Our results indicate that the predation by birds, although apparently occasional, is likely to be influenced by tadpole coloration.     

Development of single nucleotide polymorphism markers in the large and complex rubber tree genome using next-generation sequence data

The development of single nucleotide polymorphism (SNP) markers provides the opportunity to improve many areas of plant breeding and population genetics. Unfortunately, for species such as the rubber tree (Hevea brasiliensis), the use of next-generation sequencing for genomic SNP discovery is very difficult because of the large genome size and the abundance of repeated sequences. Access to a set of validated SNP markers is a significant advantage for rubber researchers who wish to apply SNPs in scientific research. Here, we performed genomic sequencing of H. brasiliensis and generated 10,993,648 short reads, which were assembled into 10,071 contigs (N50 = 3078) by a de novo assembly strategy. A total of 2446 contigs presented no hits in the current H. brasiliensis genome assembly and may therefore be considered novel genomic sequences of rubber tree. A total of 143 putative polymorphic positions were selected, gene annotations were available for 58.7 % of the markers, and all of the sequences could be anchored to the released H. brasiliensis genome. These SNPs were validated in eight genotypes of H. brasiliensis and 15 F1 plants from a mapping population, resulting in 30 (20.9 %) positions correctly classified. The analysis revealed key candidate genes responsible for defence mechanisms and provided markers for further genetic improvement of Hevea in breeding programmes.     

Balanced polymorphisms and their divergence in a Heliconius butterfly

The evolution of mimicry in similarly defended prey is well described by the Müllerian mimicry theory, which predicts the convergence of warning patterns in order to gain the most protection from predators. However, despite this prediction, we can find great diversity of color patterns among Müllerian mimics such as Heliconius butterflies in the neotropics. Furthermore, some species have evolved the ability to maintain multiple distinct warning patterns in single populations, a phenomenon known as polymorphic mimicry. The adaptive benefit of these polymorphisms is questionable since variation from the most common warning patterns is expected to be disadvantageous as novel signals are punished by predators naive to them. In this study, we use artificial butterfly models throughout Central and South America to characterize the selective pressures maintaining polymorphic mimicry in Heliconius doris. Our results highlight the complexity of positive frequency‐dependent selection, the principal selective pressure driving convergence among Müllerian mimics, and its impacts on interspecific variation of mimetic warning coloration. We further show how this selection regime can both limit and facilitate the diversification of mimetic traits.     

Development and characterization of 12 polymorphic microsatellite loci in the sea sandwort, <Emphasis Type="Italic">Honckenya peploides</Emphasis>

Codominant marker systems are better suited to analyze population structure and assess the source of an individual in admixture analyses. Currently, there is no codominant marker system using microsatellites developed for the sea sandwort, Honckenya peploides (L.) Ehrh., an early colonizer in island systems. We developed and characterized novel microsatellite loci from H. peploides, using reads collected from whole genome shotgun sequencing on a 454 platform. The combined output from two shotgun runs yielded a total of 62,669 reads, from which 58 loci were screened. We identified 12 polymorphic loci that amplified reliably and exhibited disomic inheritance. Microsatellite data were collected and characterized for the 12 polymorphic loci in two Alaskan populations of H. peploides: Fossil Beach, Kodiak Island (n?=?32) and Egg Bay, Atka Island (n?=?29). The Atka population exhibited a slightly higher average number of alleles (3.9) and observed heterozygosity (0.483) than the Kodiak population (3.3 and 0.347, respectively). The overall probability of identity values for both populations was PID?=?2.892e^?6 and PID_sib?=?3.361e^?3. We also screened the 12 polymorphic loci in Wilhelmsia physodes (Fisch. ex Ser.) McNeill, the most closely related species to H. peploides, and only one locus was polymorphic. These microsatellite markers will allow future investigations into population genetic and colonization patterns of the beach dune ruderal H. peploides on new and recently disturbed islands.     

DNA analysis reveals rich diversity of <Emphasis Type="Italic">Hydnotrya</Emphasis> with emphasis on the species found in China

Molecular analysis of the truffle genus Hydnotrya was conducted with nrDNA-ITS sequences available including newly generated sequences from Chinese specimens. Twenty-one phylotypes were recognized with the threshold of 97% ITS identity. Seven phylotypes corresponded to the described species, H. bailii, H. cerebriformis, H. cubispora, H. laojunshanensis, H. michaelis, H. cf. variiformis, and H. tulasnei, and four phylotypes represented by Chinese specimens were described and illustrated as new species, i.e., H. badia, H. brunneospora, H. nigricans, and H. puberula. The remaining ten phylotypes may represent undescribed species. Moreover, the 21 phylotypes grouped into four distinct clades each having as core species H. cerebriformis, H. cubispora, H. michaelis, and H. tulasnei, respectively, which were strongly supported by phylogenetic analysis and morphological characterization.     

New Triassic beetles (Coleoptera) from northern European Russia

Beetle remains from the Triassic Khey-Yaga locality, Nenets National District, Korotaikha Basin, Nyadeita Formation, Olenekian-Anisian are described. Only isolated elytra have been found. Tetracoleus tshalyshevi gen. et sp. nov. and T. minimus sp. nov. are described and assigned to Tricoleidae, and six new species are described in formal taxa. Tetracoleus is close to Permian tricoleids just found in the Newcastle Group of Australia and the Vyatkian Aristovo locality of northern European Russia. The composition of elytra in the locality is closer to that of Lower Triassic localities than other Middle Triassic localities and characterizes the beginning of a recovery after the Permian-Triassic ecological crisis. Longxianocupes Hong in Liu, Liu et Hong, 1985 is shown to be a junior synonym of Sogdelytron Ponomarenko, 1969. The species Palademosyne ovum Ponomarenko, 2004, P. elongatum Ponomarenko, 2004, and P. latum Ponomarenko, 2004 are transferred to the genus Pseudochrysomelites Handlirsch, 1906.     

Phylogeny of Polycladida (Platyhelminthes) based on mtDNA data

A phylogenetic analysis of Polycladida based on two partial mitochondrial genes (cox1 and 16S) is provided. The analysis includes 30 polyclad terminals that represent species from the two taxa which traditionally divide the groups Cotylea and Acotylea. Our phylogenetic analyses produced a well-supported hypothesis that confirms the monophyly of Polycladida, as well as Acotylea and Cotylea. Within Acotylea, there are two lineages not highly supported: on one hand, Leptoplanoidea (excluding Hoploplana elisabelloi) and one Stylochoidea member (Pseudostylochus intermedius) (classification sensu Faubel, 1983, 1984), and on the other hand, Stylochoidea members together with Discocelis tigrina and H. elisabelloi. The genera Stylochus and Imogine are not monophyletic. Within Cotylea, Pseudocerotidae and Euryleptidae are monophyletic, though not highly supported, while Prosthiostomidae is not. Euryleptoidea is paraphyletic. The genera Pseudobiceros and Pseudoceros are monophyletic and highly supported. Our results suggest that, within Acotylea, the prostatoid organs of Discocelis may have been derived from a prostatic vesicle. The genus Hoploplana could be included in Stylochoidea. Within Cotylea, the common ancestor of Euryleptidae and Pseudocerotidae might have been an aposematic animal with tentacles.     

An empirical test for convergence using African barbs (Cypriniformes: Cyprinidae)

Evidence for convergence is often based on overall similarity as interpreted by human eyes. We use geometric morphometrics and an analysis of phylogenetic signal to determine if similarity in form between two sympatric species of cyprinid fishes in a community from the Dja River of Cameroon is due convergence or shared evolutionary history. The two species, Enteromius aspilus and E. guirali, are deep-bodied and are very similar in color and appear to school together. The species co-occur with seven other species of Enteromius that have the more fusiform shape seen in other small barbs across Africa. Phylogenetic analysis of the mitochondrial cytochrome b and COI genes suggests that they are not sister taxa, and there is no phylogenetic signal when the phylogeny is overlaid on shape space. The convergence between the two is likely due to a variety of factors including predator avoidance and crypsis in open water, social mimicry to increase the benefit of the selfish herd effect, and increased protection of E. aspilus via Batesian mimicry of E. guirali, which has a protective dorsal spine.     

Analysis of Allelic Diversity and Genetic Relationships Among Cultivated Mangosteen (<Emphasis Type="Italic">Garcinia mangostana</Emphasis> L.) in Java,Indonesia Using Microsatellite Markers and Morphological Characters

The genetic variation and relationships of the mangosteen (Garcinia mangostana L.) were observed across mangosteen populations in Java, Indonesia using newly identified microsatellite loci and morphological characters. In this study, we developed an improved protocol to isolate microsatellite loci, named Selective Repeats from AFLP Sequence, by using a hybridized membrane. Twenty microsatellite loci were evaluated using 78 individuals from five mangosteen populations, and we successfully amplified four closely related Garcinia species, including G. malaccensis, G. hombroniana, G. celebica, and G. porrecta. Eight loci were monomorphic and the others were polymorphic. Sixty-nine alleles were found, with 3.491 per locus on an average. Genetic diversity (H?) was calculated with an average across loci within population (H?_S) as 0.39, an average loci across many populations (H?_T) as 0.444, and genetic differentiation (F?_ST) as 0.147. Furthermore, based on morphological characters, mangosteen individuals from four populations including Leuwiliang, Wanayasa, Puspahiang, and Kaligesing also had morphologically distinct fruit weight, rind weight, and rind thickness among populations. The study also elucidated the dispersal pattern of mangosteen in Java; the source of the genotype mangosteen in Java population was the Wanayasa population. In addition, we found evidence of tetraploidy in mangosteen. These results have potential applications in future breeding, conservation studies, and genetic assessment of mangosteen and their closely related species.     

Aposematic coloration does not deter corallivory by fish on the coral <Emphasis Type="Italic">Montastraea cavernosa</Emphasis>

Predation on corals by visual predators is a significant source of partial or total mortality on coral reefs, and corals have evolved strategies, including chemical defenses, to deter predation. One mechanism that organisms use to communicate the presence of chemical defenses is aposematic coloration, or the display of bright coloration as a warning to visual predators such as fish. Corals exhibit multiple colors, and it has been hypothesized that one role for this variability in coloration is as an aposematic warning of adverse palatability. Here, we test green and orange color morphs of the Caribbean coral Montastraea cavernosa for the presence of chemical defenses and whether their differences in coloration elicited different feeding responses. While M. cavernosa is chemically defended, there is no difference in feeding deterrence between color morphs; thus, the different color morphs of this coral species do not appear to represent an example of aposematic coloration.     

New jewel beetles (Coleoptera: Buprestidae) from the Cretaceous of Russia,Kazakhstan, and Mongolia

A new jewel beetle genus, with one species (Cretofrontolina kzyldzharica gen. et sp. nov.) from the Upper Cretaceous of Kazakhstan is described based on a body; and three new species of the formal genus Metabuprestium are described based on isolated elytra: Metabuprestium sibiricum sp. nov. and M. arkagalense sp. nov. come from the Arkagala locality (Upper Cretaceous of Russia) and M. ichbogdense sp. nov. is from the Shar Tologoi locality (Lower Cretaceous of Mongolia).     

New mayflies (Insecta: Ephemerida = Ephemeroptera) from the Upper Mesozoic locality of Khasurty,Western Transbaikalia

A new genus and four new species are described from the Upper Mesozoic locality of Khasurty, Western Transbaikalia: Mesobaetis crispa sp. nov. and Proameletus branchiatus sp. nov. from the family Siphlonuridae s. l., Furvoneta khasurtensis sp. nov. from Mesonetidae, and Baikalogenites firmus gen. et sp. nov. from the family Hexagenitidae. One poorly preserved specimen is identified as Mesogenesia from the family Mickoleitiidae. The unique mayfly generic assemblage of this locality, its possible age, and ecology are discussed.