Showing papers by "Niklas Wahlberg published in 2014"

The Glanville fritillary genome retains an ancient karyotype and reveals selective chromosomal fusions in Lepidoptera

Abstract: Previous studies have reported that chromosome synteny in Lepidoptera has been well conserved, yet the number of haploid chromosomes varies widely from 5 to 223. Here we report the genome (393 Mb) ...

Revised systematics and higher classification of pierid butterflies (Lepidoptera: Pieridae) based on molecular data

Abstract: The butterfly family Pieridae comprises approximately 1000 described species placed in 85 genera, but the higher classification has not yet been settled. We used molecular data from eight gene regions (one mitochondrial and seven nuclear protein-coding genes) comprising a total of ~6700 bp from 96 taxa to infer a well-supported phylogenetic hypothesis for the family. Based on this hypothesis, we revise the higher classification for all pierid genera. We resurrect the tribe Teracolini stat. rev. in the subfamily Pierinae to include the genera Teracolus, Pinacopteryx, Gideona, Ixias, Eronia, Colotis and most likely Calopieris. We transfer Hebomoia to the tribe Anthocharidini and assign the previously unplaced genera Belenois and Dixeia to the subtribe Aporiina. Three lineages near the base of Pierinae (Leptosia, Elodina and Nepheronia + Pareronia) remain unplaced. For each of these, we describe and delineate new tribes: Elodinini Braby tribus nova, Leptosiaini Braby tribus nova and Nepheroniini Braby tribus nova. The proposed higher classification is based on well-supported monophyletic groups and is likely to remain stable even with the addition of more data. (Less)

Causes of endemic radiation in the Caribbean: evidence from the historical biogeography and diversification of the butterfly genus Calisto (Nymphalidae: Satyrinae: Satyrini)

Abstract: Background: Calisto is the largest butterfly genus in the West Indies but its systematics, historical biogeography and the causes of its diversification have not been previously rigorously evaluated. Several studies attempting to explain the wide-ranging diversity of Calisto gave different weights to vicariance, dispersal and adaptive radiation. We utilized molecular phylogenetic approaches and secondary calibrations points to estimate lineage ages. In addition, we used the dispersal-extinction-cladogenesis model and Caribbean paleogeographical information to reconstruct ancestral geographical distributions. We also evaluated different models of diversification to estimate the dynamics of lineage radiation within Calisto. By understanding the evolution of Calisto butterflies, we attempt to identify the main processes acting on insular insect diversity and the causes of its origin and its maintenance. Results: The crown age of Calisto was estimated to the early Oligocene (31 ± 5 Ma), and a single shift in diversification rate following a diversity-dependent speciation process was the best explanation for the present-day diversity found within the genus. A major increase in diversification rate was recovered at 14 Ma, following geological arrangements that favoured the availability of empty niches. Inferred ancestral distributional ranges suggested that the origin of extant Calisto is in agreement with a vicariant model and the origin of the Cuban lineage was likely the result of vicariance caused by the Cuba-Hispaniola split. A long-distance dispersal was the best explanation for the colonization of Jamaica and the Bahamas. Conclusions: The ancestral geographical distribution of Calisto is in line with the paleogeographical model of Caribbean colonization, which favours island-to-island vicariance. Because the sister lineage of Calisto remains ambiguous, its arrival to the West Indies remains to be explained, although, given its age and historical biogeography, the hypothesized GAARlandia land bridge might have been a plausible introduction route from continental America. Intra-island radiation caused by ecological innovation and the abiotic creation of niche spaces was found to be the main force shaping Calisto diversity and island endemism in Hispaniola and Cuba.

Phylogeny and evolution of pharmacophagy in tiger moths (Lepidoptera: Erebidae: Arctiinae).

Abstract: The focus of this study was to reconstruct a phylogenetic hypothesis for the moth subfamily Arctiinae (tiger moths, woolly bears) to investigate the evolution of larval and adult pharmacophagy of pyrrolizidine alkaloids (PAs) and the pathway to PA chemical specialization in Arctiinae. Pharmacophagy, collection of chemicals for non-nutritive purposes, is well documented in many species, including the model species Utetheisa ornatrix L. A total of 86 exemplar ingroup species representing tiger moth tribes and subtribes (68 genera) and nine outgroup species were selected. Ingroup species included the most species-rich generic groups to represent the diversity of host-plant associations and pharmacophagous behaviors found throughout Arctiinae. Up to nine genetic markers were sequenced: one mitochondrial (COI barcode region), one nuclear rRNA (D2 region, 28S rRNA), and seven nuclear protein-coding gene fragments: elongation factor 1-α protein, wingless, ribosomal protein subunit S5, carbamoylphosphate synthase domain regions, glyceraldehyde-3-phosphate dehydrogenase, isocitrate dehydrogenase and cytosolic malate dehydrogenase. A total of 6984 bp was obtained for most species. These data were analyzed using model-based phylogenetic methods: maximum likelihood (ML) and Bayesian inference (BI). Ancestral pharmacophagous behaviors and obligate PA associations were reconstructed using the resulting Bayes topology and Reconstructing Ancestral States in Phylogenies (RASP) software. Our results corroborate earlier studies on the evolution of adult pharmacophagous behaviors, suggesting that this behavior arose multiple times and is concentrated in the phaegopterine-euchromiine-ctenuchine clade (PEC). Our results suggest that PA specialization may have arisen early in the phylogeny of the subfamily and that facultative larval pharmacophagous behaviors are the derived condition.

Multilocus Species Trees Show the Recent Adaptive Radiation of the Mimetic Heliconius Butterflies

Abstract: Mullerian mimicry among Neotropical Heliconiini butterflies is an excellent example of natural selection, and is associated with the diversification of a large continental-scale radiation. Some of the processes driving the evolution of mimicry rings are likely to generate incongruent phylogenetic signals across the assemblage, and thus pose a challenge for systematics. We use a dataset of 22 mitochondrial and nuclear markers from 92% of species in the tribe to re-examine the phylogeny of Heliconiini with both supermatrix and multi-species coalescent approaches, characterise the patterns of conflicting signal and compare the performance of various methodological approaches to reflect the heterogeneity across the data. Despite the large extent of reticulate signal and strong conflict between markers, nearly identical topologies are consistently recovered by most of the analyses, although the supermatrix approach fails to reflect the underlying variation in the history of individual loci. The first comprehensive, time-calibrated phylogeny of this group is used to test the hypotheses of a diversification rate increase driven by the dramatic environmental changes in the Amazonia over the past 23 million years, or changes caused by diversity-dependent effects on the rate of diversification. We find that the tribe Heliconiini had doubled its rate of speciation around 11 Ma and that the presently most speciose genus Heliconius started diversifying rapidly at 10 Ma, likely in response to the recent drastic changes in topography of the region. Our study provides comprehensive evidence for a rapid adaptive radiation among an important insect radiation in the most biodiverse region of the planet.

Species Delineation of Malaysian Mangrove Fireflies (Coleoptera: Lampyridae) using DNA Barcodes

Abstract: Identification and revision of firefly species are largely based on morphological characteristics. Subsequently, female firefly specimens have been neglected in taxonomic inventories because morphological descriptions relied only on male firefly specimens. In light of successful DNA barcoding in many invertebrates, this study explored the potential of DNA barcoding to complement morphological identification of fireflies in Malaysia. Firefly specimens were collected from riparian forests (including mangroves) in Peninsular Malaysia and Sarawak. Specimens were morphologically examined, and their DNA was extracted for molecular analysis. The morphological data of the male specimens was found to be congruent with molecular data, i.e., both indicated 12 species. However, inclusion of females and larvae in the DNA analysis increased the species count to 14 species. We also found distinct geographically structured variations in the DNA barcodes of two species: Pteroptyx tener Olivier and Pteroptyx bearni Olivier. The study indicates that firefly species delimitation using traditional taxonomic knowledge and new technology like DNA barcoding are compatible, therefore increasing the reliability of species identification.

Relationships within the Melitaea phoebe species group (Lepidoptera: Nymphalidae) : new insights from molecular and morphometric information

Abstract: The genus Melitaea consists of about 80 species, divided into ten species groups, which are all restricted to the Palaearctic region. The Melitaea phoebe group was defined by Higgins based on morphological characters such as wing pattern and genital structures. According to his interpretation, the M.phoebe group included seven species: M.phoebe, M.sibina, M.scotosia, M.aetherie, M.collina, M.consulis and M.turkmanica. The taxonomy of the phoebe species group has been poorly resolved and recent results on the species composition within the group suggest the need for a re-evaluation. In this study molecular sequences (5985bp) including one mitochondrial (COI) and up to six nuclear (CAD, EF-1α, GAPDH, MDH, RpS5 and wingless) gene regions from 38 specimens of the Melitaea phoebe species group sensu Higgins and some closely related taxa from the Palaearctic region were analysed. The possible evolution of the processus posterior of the male genitalia was also reconstructed based on a shape mapping technique. The analysis of the combined data shows a very clear pattern and almost all relationships are highly supported. Based on the combined Bayesian tree and the shape of the processus posterior of the male genitalia, four main groups are recognised: (i) collina group, (ii) arduinna group, (iii) aetherie group and (iv) phoebe group. The status of M.ornata, M.zagrosi and M.scotosia as species is confirmed, and the results also indicate that M.telona (s.s.) from Israel is a separate species. (Less)

Paulogramma hydarnis (n. comb.) (Nymphalidae: Biblidinae): Distribution, Systematic Position, and Conservation Status of a Rare and Endangered Butterfly.

Abstract: The nymphalid Paulogramma hydarnis (Godart) (n. comb., previously in the genus Callicore) is an endangered butterfly present in a few montane sites in the Atlantic Forest in the Southeastern Brazil. The precise systematic position of P. hydarnis was previously unknown. Based on molecular data, we find that it is sister to Paulogramma pygas (Godart) (n. comb., also previously in Callicore), a common and widespread species in the Neotropics. In addition, we find that Callicore is not monophyletic and that “Callicore” hydarnis (along with other species) is more related to the genus Paulogramma, and should thus be placed in that genus. The genus Paulogramma is now composed by the following species: Paulogramma pyracmon (Godart), Paulogramma eunomia (Hewitson) n. comb., Paulogramma hydarnis (Godart) n. comb., Paulogramma hystaspes (Fabricius) n. comb., Paulogramma pygas (Godart) n. comb., and Paulogramma tolima (Hewitson, 1852) n. comb. Museum specimens and field data report P. hydarnis in four sites in Southeastern Brazil. Recently, P. hydarnis was recorded for the first time at Parque Nacional do Caparao, states of Espirito Santo and Minas Gerais, expanding its distribution about 200 km northward of the previously known limit. Although regularly recorded in some sites, most records are historic, before the 1960s, and the current conservation situation of this species is delicate, deserving attention.

Behind Family Trees: Secondary Connections in Uralic Language Networks

Abstract: Although it has long been recognized that the family tree model is too simplistic to account for historical connections between languages, most computational studies of language history have concentrated on tree-building methods. Here, we employ computational network methods to assess the utility of network models in comparison with tree models in studying the subgrouping of Uralic languages. We also compare basic vocabulary data with words that are more easily borrowed and replaced cross-linguistically (less basic vocabulary) in order to find out how secondary connections affect computational analyses of this language family. In general, the networks support a treelike pattern of diversification, but also provide information about conflicting connections underlying some of the ambiguous divergences in the trees. These are seen as reflections of unclear divergence patterns (either in ancestral protolanguages or between languages closely related at present), which pose problems for a tree model. The networks also show that the relationships of closely related present-day languages are more complex than what the tree models suggest. When comparing less basic with basic vocabulary, we can detect the effect of borrowing between different branches (horizontal transfer) mostly between and within the Finnic and Saami subgroups. We argue that the trees obtained with basic vocabulary provide the primary pattern of the divergence of a language family, whereas networks, especially those constructed with less basic vocabulary, add reality to the picture by showing the effect of more complicated developments affecting the connections between the languages.