Patterns of Evolutionary Divergence and Convergence in the Bushy-Tailed Woodrat (Neotoma cinerea) Across Western North America

The degree of concordance between patterns of divergence in genetic and morphological characters provides insight into the process of evolutionary diversification. We analyzed species-wide morphological variation in a broadly distributed species of small mammal, the bushy-tailed woodrat (Neotoma cinerea), for comparison against a recently developed mitochondrial phylogeny. We focused our analyses on patterns of qualitative and quantitative craniodental morphological variation throughout the distribution of this taxon. We found strong concordance between the morphology of one prominent craniodental feature (sphenopalatine vacuity) and the major mitochondrial lineages, but only minimal differentiation in overall morphometric variation between these clades. Further, in contrast to the largely east–west subdivision of mitochondrial and sphenopalatine vacuity variation, cluster analyses of morphometric variation revealed a north–south morphological subdivision irrespective of mitochondrial clade. Our combined character sets are best explained by a deep history of evolutionary divergence within this taxon accompanied or followed by broad-scale convergent or parallel evolution.     

Mitochondrial diversification of the Peromyscus mexicanus species group in Nuclear Central America: biogeographic and taxonomic implications

The mountain mice of the Peromyscus mexicanus group currently encompass six known species; however, the limits between species remain uncertain, with two considered monotypic and the other four having multiple associated subspecific names. Based on the most comprehensive sampling of the group throughout its distribution in Nuclear Central America, we used data of the mitochondrial cytochrome b gene to assess its genetic diversity, phylogeny, and main biogeographic and diversification patterns. Our mitochondrial phylogeny only partially reflects the current taxonomy of the group, in agreement with some of the taxonomically recognized species. Specifically, our phylogenetic results show that the group is highly structured, including four main clades with genetic distances ranging from 11 to 8.6%. A remarkable level of differentiation is found at a more local level, defined as 15 different lineages with high nucleotide and haplotype diversity (π = 0.068, h = 0.99), and with divergence and genetic distance values (p‐uncorrected = 9.9–2.4%; K2P = 10.8–3.0%) similar to values observed between species within Peromyscus. Accordingly, we propose that the reference name P. mexicanus is polyphyletic and should be restricted to the mountains of central Mexico west of the Isthmus of Tehuantepec. We suggest to limit the other five recognized specific names to equal number of lineages, as monophyletic, and to revalidate three junior synonyms: Peromyscus salvadorensis, P. nicaraguae and P. tropicalis. The Isthmus of Tehuantepec, the Motagua‐Polochic‐Jocotán fault system, the Maya Highlands and the Honduras Depression are examples of geographic features that are likely associated with the differentiation of main lineages. Some other lineages may represent candidate species, hence the need to review the taxonomic status of the entire P. mexicanus group.     

Evolutionary drivers of phylogeographical diversity in the highlands of Mexico: a case study of the Crotalus triseriatus species group of montane rattlesnakes

Aim To assess the genealogical relationships of widespread montane rattlesnakes in the Crotalus triseriatus species group and to clarify the role of Late Neogene mountain building and Pleistocene pine–oak forest fragmentation in driving the diversification of Mexican highland taxa. Location Highlands of mainland Mexico and the south‐western United States (Texas, New Mexico, and Arizona). Methods A synthesis of inferences was used to address several associated questions about the biogeography of the Mexican highlands and the evolutionary drivers of phylogeographical diversity in co‐distributed taxa. We combined extensive range‐wide sampling (130 individuals representing five putative species) and mixed‐model phylogenetic analyses of 2408 base pairs of mitochondrial DNA to estimate genealogical relationships and divergence times within the C. triseriatus species group. We then assessed the tempo of diversification using a maximum likelihood framework based on the birth–death process. Estimated times of divergences provided a probabilistic temporal component and questioned whether diversification rates have remained constant or varied over time. Finally, we looked for phylogeographical patterns in other co‐distributed taxa. Results We identified eight major lineages within the C. triseriatus group, and inferred strong correspondence between maternal and geographic history within most lineages. At least one cryptic species was detected. Relationships among lineages were generally congruent with previous molecular studies, with differences largely attributable to our expanded taxonomic and geographic sampling. Estimated divergences between most major lineages occurred in the Late Miocene and Pliocene. Phylogeographical structure within each lineage appeared to have been generated primarily during the Pleistocene. Although the scale of genetic diversity recognized affected estimated rates of diversification, rates appeared to have been constant through time. Main conclusions The biogeographical history of the C. triseriatus group implies a dynamic history for the highlands of Mexico. The Neogene formation of the Transvolcanic Belt appears responsible for structuring geographic diversity among major lineages. Pleistocene glacial–interglacial climatic cycles and resultant expansions and contractions of the Mexican pine–oak forest appear to have driven widespread divergences within lineages. Climatic change, paired with the complex topography of Mexico, probably produced a myriad of species‐specific responses in co‐distributed Mexican highland taxa. The high degree of genetic differentiation recovered in our study and others suggests that the Mexican highlands may contain considerably more diversity than currently recognized.     

Tracing the origins of widespread highland species: a case of Neogene diversification across the Mexican sierras in an endemic lizard

The evolutionary history of the Mexican sierras has been shaped by various geological and climatic events over the past several million years. The relative impacts of these historical events on diversification in highland taxa, however, remain largely uncertain owing to a paucity of studies on broadly‐distributed montane species. We investigated the origins of genetic diversification in widely‐distributed endemic alligator lizards in the genus Barisia to help develop a better understanding of the complex processes structuring biological diversity in the Mexican highlands. We estimated lineage divergence dates and the diversification rate from mitochondrial DNA sequences, and combined divergence dates with reconstructions of ancestral geographical ranges to track lineage diversification across geography through time. Based on our results, we inferred ten geographically structured, well supported mitochondrial lineages within Barisia. Diversification of a widely‐distributed ancestor appears tied to the formation of the Trans‐Mexican Volcanic Belt across central Mexico during the Miocene and Pliocene. The formation of filter barriers such as major river drainages may have later subdivided lineages. The results of the present study provide additional support for the increasing number of studies that suggest Neogene events heavily impacted genetic diversification in widespread montane taxa. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 382–394.     

Coalescent species delimitation of a Sumatran parachuting frog

We conduct species delimitation of the widespread parachuting frog species Rhacophorus catamitus using samples from across the island of Sumatra, Indonesia. We use mitochondrial, genomic and morphological data, and find that R. catamitus is composed of three lineages corresponding to northern, central and southern lineages. Mitochondrial and genomic data show admixture or incomplete lineage sorting between the central and southern lineages, but deep divergence from the northern lineage. Coalescent species delimitation supports a three species model for this complex, and we recommend that the northern lineage be described as a new species. Our study highlights the power of coalescent species delimitation in an integrative framework for identifying unrecognised diversity in understudied tropical species complexes. We also emphasise the evolutionary importance of northern Sumatra, a region that harboured montane refugia during Pliocene–Pleistocene climate change, but has also been heavily affected by volcanic activity.     

Integrative species delimitation in Nearctic ambush bugs (Heteroptera: Reduviidae: Phymatinae): insights from molecules,geometric morphometrics and ecological associations

Ambush bugs (Hemiptera: Reduviidae: Phymatinae) are sit-and-wait predators of flower-visiting insects including pollinators. Broad species distribution ranges, intraspecific polymorphism, sexual dimorphism and subtle interspecific differences all contribute to making species delimitation especially difficult in this group, which is used as a model in the study of interactions between sexual dimorphism and sexual selection. Species boundaries among Nearctic ambush bugs in the common and frequently collected erosa species group (11 species, nine subspecies) have therefore remained unclear, resulting in a complex and poorly justified taxonomy. Recent molecular phylogenetic research suggested that several widespread Nearctic species are para- or polyphyletic. We here build on this research, integrating geometric morphometrics, molecular species delimitation approaches and host plant association data to provide a comprehensive dataset with respect to both taxon and character sampling with the goal of teasing apart evolutionary lineages of Nearctic Phymata Latreille. Although molecular-based species delimitation analyses suggested a variety of species hypotheses, probably as a result of striking discordance between mitochondrial and nuclear ribosomal genes, the combination of these with geometric morphometric data enabled us to confidently delimit several of these problematic taxa. In addition, geometric morphometric analysis of pronotal shape revealed undocumented morphological patterns that appear to be useful in the diagnosis of many of the surveyed taxa. The results from this study provide an objective foundation for the much-needed taxonomic revision of the most ubiquitous ambush bugs in North America.     

Evolution along the Great Rift Valley: phenotypic and genetic differentiation of East African white‐eyes (Aves,Zosteropidae)

The moist and cool cloud forests of East Africa represent a network of isolated habitats that are separated by dry and warm lowland savannah, offering an opportunity to investigate how strikingly different selective regimes affect species diversification. Here, we used the passerine genus Zosterops (white‐eyes) from this region as our model system. Species of the genus occur in contrasting distribution settings, with geographical mountain isolation driving diversification, and savannah interconnectivity preventing differentiation. We analyze (1) patterns of phenotypic and genetic differentiation in high‐ and lowland species (different distribution settings), (2) investigate the potential effects of natural selection and temporal and spatial isolation (evolutionary drivers), and (3) critically review the taxonomy of this species complex. We found strong phenotypic and genetic differentiation among and within the three focal species, both in the highland species complex and in the lowland taxa. Altitude was a stronger predictor of phenotypic patterns than the current taxonomic classification. We found longitudinal and latitudinal phenotypic gradients for all three species. Furthermore, wing length and body weight were significantly correlated with altitude and habitat type in the highland species Z. poliogaster. Genetic and phenotypic divergence showed contrasting inter‐ and intraspecific structures. We suggest that the evolution of phenotypic characters is mainly driven by natural selection due to differences in the two macro‐habitats, cloud forest and savannah. In contrast, patterns of neutral genetic variation appear to be rather driven by geographical isolation of the respective mountain massifs. Populations of the Z. poliogaster complex, as well as Z. senegalensis and Z. abyssinicus, are not monophyletic based on microsatellite data and have higher levels of intraspecific differentiation compared to the currently accepted species.     

Fine-scale phenotypic change across a species transition zone in the genus neotoma: disentangling independent evolution from phylogenetic history

Zones of secondary contact between closely related species provide a rare opportunity to examine evidence of evolutionary processes that reinforce species boundaries and/or promote diversification. Here, we report on genetic and morphological variation in two sister species of woodrats, Neotoma fuscipes and N. macrotis, across a 30-km transition zone in the Sierra Nevada of California. We assessed whether these lineages readily hybridize, and whether their morphology suggests ecological interactions favoring phenotypic diversification. We combined measurements of body size and 11 craniodental traits from nine populations with genetic data to examine patterns of variation within and between species. We used phylogenetic autocorrelation methods to estimate the degree to which phenotypic variation in our dataset arose from independent evolution within populations versus phylogenetic history. Although no current sympatry or hybridization was evident, craniodental morphology diverged in both lineages near their distributional limits, whereas body size converged. The shift in craniodental morphology arose independently within populations whereas body size retained a strong phylogenetic signal, yet both patterns are consistent with expectations of phenotypic change based on different models of resource competition. Our findings demonstrate the importance of examining a suite of morphological traits across contact zones to provide a more complete picture of potential ecological interactions: competition may drive both diversification and convergence in different phenotypic traits.     

Paraphyletic species no more – genomic data resolve a Pleistocene radiation and validate morphological species of the Melanoplus scudderi complex (Insecta: Orthoptera)

Rapid speciation events, with taxa generated over a short time period, are among the most investigated biological phenomena. However, molecular systematics often reveals contradictory results compared with morphological/phenotypical diagnoses of species under scenarios of recent and rapid diversification. In this study, we used molecular data from an average of over 29 000 loci per sample from RADseq to reconstruct the diversification history and delimit the species boundary in a short-winged grasshopper species complex (Melanoplus scudderi group), where Pleistocene diversification has been hypothesized to generate more than 20 putative species with distinct male genitalic shapes. We found that, based on a maximum likelihood molecular phylogeny, each morphological species indeed forms a monophyletic group, contrary to the result from a previous mitochondrial DNA sequence study. By dating the diversification events, the species complex is estimated to have diversified during the Late Pleistocene, supporting the recent radiation hypothesis. Furthermore, coalescent-based species delimitation analyses provide quantitative support for independent genetic lineages, which corresponds to the morphologically defined species. Our results also showed that male genitalic shape may not be predicted by evolutionary distance among species, not only indicating that this trait is labile, but also implying that selection may play a role in character divergence. Additionally, our findings suggest that the rapid speciation events in this flightless grasshopper complex might be primarily associated with the fragmentation of their grassland habitats during the Late Pleistocene. Collectively, our study highlights the importance of integrating multiple sources of information to delineate species, especially for a species complex that diversified rapidly, and whose divergence may be linked to ecological processes that create geographic isolation (i.e. fragmented habitats), as well as selection acting on characters with direct consequences for reproductive isolation (i.e. genitalic divergence).     

Are the Northern Andes a species pump for Neotropical birds? Phylogenetics and biogeography of a clade of Neotropical tanagers (Aves: Thraupini)

Aim We used mitochondrial DNA sequence data to reconstruct the phylogeny of a large clade of tanagers (Aves: Thraupini). We used the phylogeny of this Neotropical bird group to identify areas of vicariance, reconstruct ancestral zoogeographical areas and elevational distributions, and to investigate the correspondence of geological events to speciation events. Location The species investigated are found in 18 of the 22 zoogeographical regions of South America, Central America and the Caribbean islands; therefore, we were able to use the phylogeny to address the biogeographical history of the entire region. Methods Molecular sequence data were gathered from two mitochondrial markers (cytochrome b and ND2) and analysed using Bayesian and maximum‐likelihood approaches. Dispersal–vicariance analysis (DIVA) was used to reconstruct zoogeographical areas and elevational distributions. A Bayesian framework was also used to address changes in elevation during the evolutionary history of the group. Results Our phylogeny was similar to previous tanager phylogenies constructed using fewer species; however, we identified three genera that are not monophyletic and uncovered high levels of sequence divergence within some species. DIVA identified early diverging nodes as having a Northern Andean distribution, and the most recent common ancestor of the species included in this study occurred at high elevations. Most speciation events occurred either within highland areas or within lowland areas, with few exchanges occurring between the highlands and lowlands. The Northern Andes has been a source for lineages in other regions, with more dispersals out of this area relative to dispersals into this area. Most of the dispersals out of the Northern Andes were dispersals into the Central Andes; however, a few key dispersal events were identified out of the Andes and into other zoogeographical regions. Main conclusions The timing of diversification of these tanagers correlates well with the main uplift of the Northern Andes, with the highest rate of speciation occurring during this timeframe. Central American tanagers included in this study originated from South American lineages, and the timing of their dispersal into Central America coincides with or post‐dates the completion of the Panamanian isthmus.     

Diversification in the Mexican horned lizard Phrynosoma orbiculare across a dynamic landscape

The widespread montane Mexican horned lizard Phrynosoma orbiculare (Squamata: Phrynosomatidae) represents an ideal species to investigate the relative impacts of Neogene vicariance and Quaternary climate change on lineage diversification across the Mexican highlands. We used mitochondrial DNA to examine the maternal history of P. orbiculare and estimate the timing and tempo of lineage diversification. Based on our results, we inferred 11 geographically structured, well supported mitochondrial lineages within this species, suggesting P. orbiculare represents a species complex. Six divergences between lineages likely occurred during the Late Miocene and Pliocene, and four splits probably happened during the Pleistocene. Diversification rate appeared relatively constant through time. Spatial and temporal divergences between lineages of P. orbiculare and co-distributed taxa suggest that a distinct period of uplifting of the Transvolcanic Belt around 7.5-3 million years ago broadly impacted diversification in taxa associated with this mountain range. To the north, several river drainages acting as filter barriers differentially subdivided co-distributed highland taxa through time. Diversification patterns observed in P. orbiculare provide additional insight into the mechanisms that impacted differentiation of highland taxa across the complex Mexican highlands.     

Integration of conflict into integrative taxonomy: fitting hybridization in species delimitation of Mesocarabus (Coleoptera: Carabidae)

In species differentiation, characters may not diverge synchronously, and there are also processes that shuffle character states in lineages descendant from a common ancestor. Species are thus expected to show some degree of incongruence among characters; therefore, taxonomic delimitation can benefit from integrative approaches and objective strategies that account for character conflict. We illustrate the potential of exploiting conflict for species delimitation in a study case of ground beetles of the subgenus Carabus (Mesocarabus), where traditional taxonomy does not accurately delimit species. The molecular phylogenies of four mitochondrial and three nuclear genes, cladistic analysis of the aedeagus, ecological niche divergence and morphometry of pronotal shape in more than 500 specimens of Mesocarabus show that these characters are not fully congruent. For these data, a three‐step operational strategy is proposed for species delimitation by (i) delineating candidate species based on the integration of incongruence among conclusive lines of evidence, (ii) corroborating candidate species with inconclusive lines of evidence and (iii) refining a final species proposal based on an integrated characterization of candidate species based on the evolutionary analysis of incongruence. This procedure provided a general understanding of the reticulate process of hybridization and introgression acting on Mesocarabus and generated the hypothesis of seven Mesocarabus species, including two putative hybrid lineages. Our work emphasizes the importance of incorporating critical analyses of character and phylogenetic conflict to infer both the evolutionary history and species boundaries through an integrative taxonomic approach.     

Species and shape diversification are inversely correlated among gobies and cardinalfishes (Teleostei: Gobiiformes)

Gobies and their relatives are significant components of nearshore marine, estuarine, and freshwater fish faunas in both tropical and temperate habitats worldwide. They are remarkable for their ability to adapt to and diversify in a wide range of environments. Among gobiiform clades, species diversities vary widely, ranging from two species in Kurtidae to more than 1,000 species in Gobiidae. There is also great variation in head and body shape and in environmental preferences (fresh, brackish, or marine habitats). In this study, I used a time-calibrated molecular phylogeny, coupled with morphometric and comparative analyses, to examine evolutionary rates of both speciation and morphological diversification among gobiiform lineages. Projection of the phylogeny onto a shape-derived morphospace shows that Gobioidei is morphometrically distinct from its sister taxon Apogonoidei, but that families within Gobioidei overlap in morphospace. Analysis of species diversification rates indicates that three rate shifts have occurred over the evolutionary history of Gobiiformes. Relative to the other lineages, Kurtidae has exhibited a slowdown in speciation, whereas both Apogonidae and Gobiidae?+?Gobionellidae have experienced an increase in diversification. Comparative analyses show that in Apogonidae and Gobiidae?+?Gobionellidae, increased speciation is correlated with diminished rates of morphological diversification, differently manifested in either clade and among the various sublineages. The elevation in speciation rates and diminishment in rates of morphological change in both Apogonidae and the clade Gobiidae?+?Gobionellidae are correlated with shifts to oceanic habitats from freshwater. This pattern is the complement to that seen across the global radiation of acanthomorph fishes in which a decrease in species diversification is associated with an increase in morphological disparity.     

The effect of environmental diversification on species diversification in New Caledonian caddisflies (Insecta: Trichoptera: Hydropsychidae)

Aim To test whether environmental diversification played a role in the diversification of the New Caledonian Hydropsychinae caddisflies. Location New Caledonia, south‐west Pacific. Methods The phylogeny of the New Caledonian Hydropsychinae caddisflies was hypothesized using parsimony and Bayesian methods on molecular characters. The Bayesian analysis was the basis for a comparative analysis of the correlation between phylogeny and three environmental factors: geological substrate (ultrabasic, non‐ultrabasic), elevation and precipitation. Phylogenetic divergence times were estimated using a relaxed clock method, and environmental factors were mapped onto a lineage‐through‐time plot to investigate the timing of environmental diversification in relation to species radiation. The correlation between rainfall and elevation was tested using independent contrasts, and the gamma statistic was calculated to infer the diversification pattern of the group. Results The diversification of extant Orthopsyche–Caledopsyche species began in the Middle–Late Oligocene, when much of the island of New Caledonia was covered by ultrabasic substrate and mountain forming was prevalent. Most lineages originated in the Middle–Late Miocene, a period associated with long‐term climate oscillation. Optimization of environmental factors on the phylogeny demonstrated that the New Caledonian Hydropsychinae group adapted to ultrabasic substrate early in its evolutionary history. The clade living mostly on ultrabasic substrate was far more species‐rich than the clade living mostly on non‐ultrabasic substrate. Elevation and rainfall were significantly correlated with each other. The lineage‐through‐time plot revealed that the main environmental diversification preceded species diversification. A constant speciation through time was rejected, and the negative gamma indicates that most of the diversification occurred early in the history of the clade. According to the inferred phylogeny, the genus Orthopsyche McFarlane is a synonym under Caledopsyche Kimmins, and Abacaria caledona Oláh & Barnard should also be included in Caledopsyche. Main conclusions The age of the radiation does not support a vicariance origin of New Caledonian Hydropsychinae caddisflies. Environmental diversification pre‐dates lineage diversification, and thus environmental heterogeneity potentially played a role in the diversification of the group, by providing a variety of fragmented habitats to disperse into, promoting speciation. The negative gamma indicates that the speciation rate slowed as niches started to fill.     

Systematics and evolutionary relationships of the mountain lizard Liolaemus monticola (Liolaemini): how morphological and molecular evidence contributes to reveal hidden species diversity

The delimitation of species is a major issue in systematic biology and has been a re-emerging discipline in the last decade. A number of studies have shown that the use of multiple data sets is critical for the identification of cryptic species, particularly in groups with complex evolutionary histories. Liolaemus monticola is a montane lizard species distributed in central Chile (32°–42°S), with four described subspecies in a latitudinal gradient from north to south: L. m. monticola , L. m. chillanensis , L. monticola ssp. and L. m. villaricensis . In order to test the systematic status and phylogenetic relationships of the taxa included in the L. monticola group, we analysed morphological (morphometric and meristic) and molecular (allozyme and mitochondrial DNA) data sets. The results of the morphological analyses showed that meristic variables correctly assigned individuals with higher accuracy than did morphometric characters. The results of the analyses of allozyme data revealed eight diagnostic loci that are evidence for significant differences among the four L. monticola subspecies. Phylogenetic analyses with mitochondrial DNA data, including additional species, showed that the L. monticola group is polyphyletic. We postulate that the four current subspecies represent independent evolutionary lineages and must be raised to the specific level as L. monticola , L. chillanensis and L. villaricensis . The taxonomic status of the unnamed L. monticola ssp. remains unresolved, although we provide a preliminary proposal.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 96 , 635–650.     

Delimitation despite discordance: Evaluating the species limits of a confounding species complex in the face of mitonuclear discordance

The delimitation of species is an essential pursuit of biology, and proper taxonomies are crucial for the assessment and conservation management of organismal diversity. However, delimiting species can be hindered by a number of factors including highly conserved morphologies (e.g., cryptic species), differences in criteria of species concepts, lineages being in the early stages of the speciation or divergence process, and discordance between gene topologies (e.g., mitonuclear discordance). Here we use a taxonomically confounded species complex of toads in Central America that exhibits extensive mitonuclear discordance to test delimitation hypotheses. Our investigation integrates mitochondrial sequences, nuclear SNPs, morphology, and macroecological data to determine which taxonomy best explains the divergence and evolutionary relationships among these toads. We found that a three species taxonomy following the distributions of the nuclear SNP haplotypes offers the best explanation of the species in this complex based off of the integrated data types. Due to the taxonomic instability of this group, we also discuss conservation concerns in the face of improper taxonomic delimitation. Our study provides an empirical and integrative hypothesis testing framework to assess species delimitation hypotheses in the face of cryptic morphology and mitonuclear discordance and highlights the importance that a stable taxonomy has over conservation‐related actions.     

Evolutionary differentiation in the Neotropical montane region: molecular phylogenetics and phylogeography of Buarremon brush-finches (Aves, Emberizidae)

Studies on Neotropical phylogeography have largely focused on lowland organisms. Because lowland and highland biotas have different histories and are likely affected by different processes influencing population differentiation, understanding Neotropical diversification requires detailed studies on montane taxa. We present the most comprehensive analysis of population differentiation conducted so far on a widespread group of Neotropical montane organisms, focusing on the evolutionary relationships and phylogeography of Buarremon brush-finches (Aves: Emberizidae) in montane areas from Mexico through Argentina. Sequences of mitochondrial and nuclear genes demonstrate that Buarremon is not monophyletic with respect to Arremon and Lysurus. Genetic structure revealed by mtDNA is strong in both B. brunneinucha and B. torquatus. Gene genealogies and nucleotide diversity indicate that B. brunneinucha originated in Mexico and later expanded to South America, where it followed one colonization route through the east, and one through the west of the continent. Differentiation among populations of B. torquatus was substantial, reaching 8% uncorrected sequence divergence within South America. Relationships among major lineages of B. torquatus were not fully resolved owing to rapid differentiation, but the occurrence of closely related taxa in distant locations suggests a complex history of diversification. Some Colombian populations of B. brunneinucha have affinities with populations from Venezuela and the East Andean slope of Ecuador and Peru, and others with those from the Pacific slope of Ecuador. Moreover, five divergent lineages of B. torquatus occur within Colombia, highlighting the importance of dense sampling in northwest South America for studies on diversification of widespread Neotropical lineages.     

Detecting cryptic species in sympatry and allopatry: analysis of hidden diversity in Polyommatus (Agrodiaetus) butterflies (Lepidoptera: Lycaenidae)

Modern multilocus molecular techniques are a powerful tool in the detection and analysis of cryptic taxa. However, its shortcoming is that with allopatric populations it reveals phylogenetic lineages, not biological species. The increasing power of coalescent multilocus analysis leads to the situation in which nearly every geographically isolated or semi‐isolated population can be identified as a lineage and therefore raised to species rank. It leads to artificial taxonomic inflation and as a consequence creates an unnecessary burden on the conservation of biodiversity. To solve this problem, we suggest combining modern lineage delimitation techniques with the biological species concept. We discuss several explicit principles on how genetic markers can be used to detect cryptic entities that have properties of biological species (i.e. of actually or potentially reproductively isolated taxa). Using these principles we rearranged the taxonomy of the butterfly species close to Polyommatus (Agrodiaetus) ripartii. The subgenus Agrodiaetus is a model system in evolutionary research, but its taxonomy is poorly elaborated because, as a rule, most of its species are morphologically poorly differentiated. The taxon P. (A.) valiabadi has been supposed to be one of the few exceptions from this rule due to its accurately distinguishable wing pattern. We discovered that in fact traditionally recognized P. valiabadi is a triplet of cryptic species, strongly differentiated by their karyotypes and mitochondrial haplotypes.