Language and ethnobiological skills decline precipitously in Papua New Guinea, the world's most linguistically diverse nation.

Papua New Guinea is home to >10% of the world's languages and rich and varied biocultural knowledge, but the future of this diversity remains unclear. We measured language skills of 6,190 students speaking 392 languages (5.5% of the global total) and modeled their future trends using individual-level variables characterizing family language use, socioeconomic conditions, students' skills, and language traits. This approach showed that only 58% of the students, compared to 91% of their parents, were fluent in indigenous languages, while the trends in key drivers of language skills (language use at home, proportion of mixed-language families, urbanization, students' traditional skills) predicted accelerating decline of fluency to an estimated 26% in the next generation of students. Ethnobiological knowledge declined in close parallel with language skills. Varied medicinal plant uses known to the students speaking indigenous languages are replaced by a few, mostly nonnative species for the students speaking English or Tok Pisin, the national lingua franca. Most (88%) students want to teach indigenous language to their children. While crucial for keeping languages alive, this intention faces powerful external pressures as key factors (education, cash economy, road networks, and urbanization) associated with language attrition are valued in contemporary society.

Different phylogenomic methods support monophyly of enigmatic 'Mesozoa' (Dicyemida + Orthonectida, Lophotrochozoa).

Dicyemids and orthonectids were traditionally classified in a group called Mesozoa, but their placement in a single clade has been contested and their position(s) within Metazoa is uncertain. Here, we assembled a comprehensive matrix of Lophotrochozoa (Metazoa) and investigated the position of Dicyemida (= Rhombozoa) and Orthonectida, employing multiple phylogenomic approaches. We sequenced seven new transcriptomes and one draft genome from dicyemids (Dicyema, Dicyemennea) and two transcriptomes from orthonectids (Rhopalura). Using these and published data, we assembled and analysed contamination-filtered datasets with up to 987 genes. Our results recover Mesozoa monophyletic and as a close relative of Platyhelminthes or Gnathifera. Because of the tendency of the long-branch mesozoans to group with other long-branch taxa in our analyses, we explored the impact of approaches purported to help alleviate long-branch attraction (e.g. taxon removal, coalescent inference, gene targeting). None of these were able to break the association of Orthonectida with Dicyemida in the maximum-likelihood trees. Contrastingly, the Bayesian analysis and site-specific frequency model in maximum-likelihood did not recover a monophyletic Mesozoa (but only when using a specific 50 gene matrix). The classic hypothesis on monophyletic Mesozoa is possibly reborn and should be further tested.

Evolution of life history and behavior in Hominidae: towards phylogenetic reconstruction of the chimpanzee-human last common ancestor.

The origin of the fundamental behavioral differences between humans and our closest living relatives is one of the central issues of evolutionary anthropology. The prominent, chimpanzee-based referential model of early hominin behavior has recently been challenged on the basis of broad multispecies comparisons and newly discovered fossil evidence. Here, we argue that while behavioral data on extant great apes are extremely relevant for reconstruction of ancestral behaviors, these behaviors should be reconstructed trait by trait using formal phylogenetic methods. Using the widely accepted hominoid phylogenetic tree, we perform a series of character optimization analyses using 65 selected life-history and behavioral characters for all extant hominid species. This analysis allows us to reconstruct the character states of the last common ancestors of Hominoidea, Hominidae, and the chimpanzee-human last common ancestor. Our analyses demonstrate that many fundamental behavioral and life-history attributes of hominids (including humans) are evidently ancient and likely inherited from the common ancestor of all hominids. However, numerous behaviors present in extant great apes represent their own terminal autapomorphies (both uniquely derived and homoplastic). Any evolutionary model that uses a single extant species to explain behavioral evolution of early hominins is therefore of limited use. In contrast, phylogenetic reconstruction of ancestral states is able to provide a detailed suite of behavioral, ecological and life-history characters for each hypothetical ancestor. The living great apes therefore play an important role for the confident identification of the traits found in the chimpanzee-human last common ancestor, some of which are likely to represent behaviors of the fossil hominins.

Multilocus phylogeny of Crenicichla (Teleostei: Cichlidae), with biogeography of the C. lacustris group: species flocks as a model for sympatric speciation in rivers.

First multilocus analysis of the largest Neotropical cichlid genus Crenicichla combining mitochondrial (cytb, ND2, 16S) and nuclear (S7 intron 1) genes and comprising 602 sequences of 169 specimens yields a robust phylogenetic hypothesis. The best marker in the combined analysis is the ND2 gene which contributes throughout the whole range of hierarchical levels in the tree and shows weak effects of saturation at the 3rd codon position. The 16S locus exerts almost no influence on the inferred phylogeny. The nuclear S7 intron 1 resolves mainly deeper nodes. Crenicichla is split into two main clades: (1) Teleocichla, the Crenicichla wallacii group, and the Crenicichla lugubris-Crenicichla saxatilis groups ("the TWLuS clade"); (2) the Crenicichla reticulata group and the Crenicichla lacustris group-Crenicichla macrophthalma ("the RMLa clade"). Our study confirms the monophyly of the C. lacustris species group with very high support. The biogeographic reconstruction of the C. lacustris group using dispersal-vicariance analysis underlines the importance of ancient barriers between the middle and upper Paraná River (the Guaíra Falls) and between the middle and upper Uruguay River (the Moconá Falls). Our phylogeny recovers two endemic species flocks within the C. lacustris group, the Crenicichla missioneira species flock and the herein discovered Crenicichla mandelburgeri species flock from the Uruguay and Paraná/Iguazú Rivers, respectively. We discuss putative sympatric diversification of trophic traits (morphology of jaws and lips, dentition) and propose these species flocks as models for studying sympatric speciation in complex riverine systems. The possible role of hybridization as a mechanism of speciation is mentioned with a recorded example (Crenicichla scottii).

Paternity Uncertainty and Parent-Offspring Conflict Explain Restrictions on Female Premarital Sex across Societies.

Although norms of premarital sex vary cross-culturally, the sexuality of adolescent girls has been consistently more restricted than that of adolescent boys. Three major theories that attempt to explain restrictions on female premarital sex (FPS) concern male, female, and parental control. These competing theories have not been tested against each other cross-culturally. In this study, we do this using a sample of 128 nonindustrial societies and socioecological predictors capturing extramarital sex, paternal care, female status, sex ratio, parental control over a daughter's mate choice, residence, and marriage transactions, while also controlling for phylogenetic non-independence across societies. We found that multiple parties benefit from restrictions on FPS. Specifically, FPS is more restricted in societies intolerant of extramarital sex and where men transfer property to their children (male control), as well as where marriages are arranged by parents (parental control). Both paternity uncertainty (partitioned among marital fidelity and paternal investment) and parent-offspring conflict (prompting parents to control their daughter's sexuality) were identified as possible mechanisms of FPS restrictions. The evidence for female control is ambiguous, mainly because it can be equally well interpreted as both male control and parental control, and because fathers, rather than mothers, are often the primary decision makers about a daughter's mate choice. Our results also emphasize the importance of social roles, rather than stereotyped sex roles, as a more useful approach to understanding the evolution of FPS restrictions.

Global phylogenetic analysis reveals multiple origins and correlates of genital mutilation/cutting.

Genital mutilation/cutting is costly in terms of health, survival and reproduction, and the long-term maintenance of these practices is an evolutionary conundrum. Previous studies have suggested a mate-guarding function or various signalling functions of genital mutilation/cutting. Here we use phylogenetic comparative methods and two global ethnographic samples to study the origins and socio-ecological correlates of major types of female and male genital mutilation/cutting. Male genital mutilation/cutting probably originated in polygynous societies with separate residence of co-wives, supporting a mate-guarding function. Female genital mutilation/cutting originated subsequently and almost exclusively in societies already practising male genital mutilation/cutting, where it may have become a signal of chastity. Both have originated multiple times, some as early as in the mid-Holocene (5,000-7,000 years ago), considerably predating the earliest archaeological evidence and written records. Genital mutilation/cutting co-evolves with and may help maintain fundamental social structures, hindering efforts to change these cultural practices.

Range size heritability in Carnivora is driven by geographic constraints.

Range size heritability refers to an intriguing pattern where closely related species occupy geographic ranges of similar extent. Its existence may indicate selection on traits emergent only at the species level, with interesting consequences for evolutionary processes. We explore whether range size heritability may be attributable to the fact that range size is largely driven by the size of geographic domains (i.e., continents, biomes, areas given by species' climatic tolerance) that tend to be similar in phylogenetically related species. Using a well-resolved phylogeny of Carnivora, we show that range sizes are indeed constrained by geographic domains and that the phylogenetic signal in range sizes diminishes if the domain sizes are accounted for. Moreover, more detailed delimitation of species' geographic domain leads to a weaker signal in range size heritability, indicating the importance of definition of the null model against which the pattern is tested. Our findings do not reject the hypothesis of range size heritability but rather unravel its underlying mechanisms. Additional analyses imply that evolutionary conservatism in niche breadth delimits the species' geographic domain, which in turn shapes the species' range size. Range size heritability patterns thus emerge as a consequence of this interplay between evolutionary and geographic constraints.

Identifying post-marital residence patterns in prehistory: A phylogenetic comparative analysis of dwelling size.

Post-marital residence patterns are an important aspect of human social organization. However, identifying such patterns in prehistoric societies is challenging since they leave almost no direct traces in archaeological records. Cross-cultural researchers have attempted to identify correlates of post-marital residence through the statistical analysis of ethnographic data. Several studies have demonstrated that, in agricultural societies, large dwellings (over ca. 65 m2) are associated with matrilocality (spouse resides with or near the wife's family), whereas smaller dwellings are associated with patrilocality (spouse resides with or near the husband's family). In the present study, we tested the association between post-marital residence and dwelling size (average house floor area) using phylogenetic comparative methods and a global sample of 86 pre-industrial societies, 22 of which were matrilocal. Our analysis included the presence of agriculture, sedentism, and durability of house construction material as additional explanatory variables. The results confirm a strong association between matrilocality and dwelling size, although very large dwellings (over ca. 200 m2) were found to be associated with all types of post-marital residence. The best model combined dwelling size, post-marital residence pattern, and sedentism, the latter being the single best predictor of house size. The effect of agriculture on dwelling size becomes insignificant once the fixity of settlement is taken into account. Our results indicate that post-marital residence and house size evolve in a correlated fashion, namely that matrilocality is a predictable response to an increase in dwelling size. As such, we suggest that reliable inferences about the social organization of prehistoric societies can be made from archaeological records.

Phylogeny of Annelida (Lophotrochozoa): total-evidence analysis of morphology and six genes.

BACKGROUND: Annelida is one of the major protostome phyla, whose deep phylogeny is very poorly understood. Recent molecular phylogenies show that Annelida may include groups once considered separate phyla (Pogonophora, Echiurida, and Sipunculida) and that Clitellata are derived polychaetes. SThe "total-evidence" analyses combining morphological and molecular characters have been published for a few annelid taxa. No attempt has yet been made to analyse simultaneously morphological and molecular information concerning the Annelida as a whole. RESULTS: Phylogenetic relationships within Annelida were analysed on the basis of 93 morphological characters and sequences of six genes (18S, 28S, and 16S rRNA, EF1alpha, H3, COI), altogether, 87 terminals of all annelid "families" and 3,903 informative characters, by Bayesian and maximum-parsimony methods. The analysis of the combined dataset yields the following scheme of relationships: Phyllodocida and Eunicida are monophyletic groups, together probably forming monophyletic Aciculata (incl. Orbiniidae and Parergodrilidae that form a sister group of the Eunicida). The traditional "Scolecida" and "Canalipalpata" are both polyphyletic, forming instead two clades: one including Cirratuliformia and the "sabelloid-spionoid clade" (incl. Sternaspis, Sabellidae-Serpulidae, Sabellariidae, Spionida s.str.), the other ("terebelloid-capitelloid clade") including Terebelliformia, Arenicolidae-Maldanidae, and Capitellidae-Echiurida. The Clitellata and "clitellate-like polychaetes" (Aeolosomatidae, Potamodrilidae, Hrabeiella) form a monophyletic group. The position of the remaining annelid groups is uncertain--the most problematic taxa are the Opheliidae-Scalibregmatidae clade, the Amphinomida-Aberranta clade, Apistobranchus, Chaetopteridae, Myzostomida, the Sipunculida-Dinophilidae clade, and the "core Archiannelida" (= Protodrilidae, Nerillidae, Polygordiidae, Saccocirridae). CONCLUSION: The combined ("total-evidence") phylogenetic analysis provides a modified view of annelid evolution, with several higher-level taxa, i.e. Phyllodocida, Eunicida, orbinioid-parergodrilid clade (OPC), Cirratuliformia, sabelloid-spionoid clade (SSC), terebelloid-capitelloid clade (TCC), and "Clitellatomorpha". Two unorthodox clades, the "core Archiannelida" and Sipunculida-Dinophilidae, are proposed. Although the deep-level evolutionary relationships of Annelida remain poorly understood, we propose the monophyly of the Aciculata, sister-group relationships between the Eunicida and OPC, between the Cirratuliformia and SSC, and possibly also between the "Clitellatomorpha" and Oweniidae-Pogonophora clades.

Ultrastructure, development, and homology of insect embryonic cuticles.

Ultrastructure and deposition of the cuticles secreted by embryos representing eight insect orders were examined by transmission and scanning electron microscopy. Embryos of the apterygote silverfish Thermobia domestica deposit two embryonic cuticles. Deposition of the first (EC1) is initiated at the beginning of appendage development when the intercalary segment and the neural groove are clearly visible. This cuticle lacks surface microsculpture and consists of an outer epicuticle and an underlying fibrous layer, thought to represent procuticle. At the time of dorsal closure, deposition of a second embryonic cuticle (EC2) begins; this bears sensilla and functions in the first instar larva. In representative embryos of seven pterygote orders (Ephemeroptera, Odonata, Plecoptera, Neuroptera, Coleoptera, Lepidoptera, and Mecoptera), three cuticles were found to be secreted. The first cuticle in pterygotes is homologous to EC1 of T. domestica, but consists solely of outer epicuticle. EC2, the "prolarval cuticle," bears a characteristic surface microsculpture in embryos of some species and egg-teeth and other hatching devices, and consists of outer and inner epicuticles and a more or less reduced procuticle. EC2 is reduced in the embryos of derived endopterygotes, where a procuticle is lacking and the inner epicuticle is reduced. After hatching, when EC2 is shed, the first instar larva is covered by a third embryonic cuticle (EC3), whose deposition was initiated while the insect was still within the egg. Presence of only two embryonic cuticles in cyclorrhaphous flies is due to the total loss of prolarval cuticle. Investigated exopterygote and endopterygote insects excluding flies thus deposit three embryonic cuticles, and their juveniles (exopterygote "nymphs"; endopterygote "larvae") seem to hatch at equivalent stages of development. Differences between the modes of cuticulogenesis in silverfish and pterygote embryos suggest that the apterygote first larval instar was embryonized and became a fully embryonic prolarva in pterygotes.

Regional patterns of postglacial changes in the Palearctic mammalian diversity indicate retreat to Siberian steppes rather than extinction.

We examined the presence of possible Recent refugia of Pleistocene mammalian faunas in Eurasia by analysing regional differences in the mammalian species composition, occurrence and extinction rates between Recent and Last Glacial faunas. Our analyses revealed that most of the widespread Last Glacial species have survived in the central Palearctic continental regions, most prominently in Altai-Sayan (followed by Kazakhstan and East European Plain). The Recent Altai-Sayan and Kazakhstan regions show species compositions very similar to their Pleistocene counterparts. The Palearctic regions have lost 12% of their mammalian species during the last 109,000 years. The major patterns of the postglacial changes in Palearctic mammalian diversity were not extinctions but rather radical shifts of species distribution ranges. Most of the Pleistocene mammalian fauna retreated eastwards, to the central Eurasian steppes, instead of northwards to the Arctic regions, considered Holocene refugia of Pleistocene megafauna. The central Eurasian Altai and Sayan mountains could thus be considered a present-day refugium of the Last Glacial biota, including mammals.

Phylogeny of the New World Dysdercus (Insecta: Hemiptera: Pyrrhocoridae) and Evolution of their Colour Patterns.

Evolution of colour patterns is reconstructed in the case of the New World species of Dysdercus (Hemiptera: Pyrrhocoridae). The phylogenetic species concept was applied to this group, elevating five subspecific taxa to specific rank (D. capitatus, D. discolor, D. fervidus, D. luteus, and D. neglectus), and the resulting 41 phylogenetic species were analysed cladistically. Using optimization methods, evolution of colour patterns of the group is hypothesized, and possible developmental mechanisms of colour-pattern evolutionary changes are inferred.

Myzostomida Are Not Annelids: Molecular and Morphological Support for a Clade of Animals with Anterior Sperm Flagella.

The myzostomes are animals with five pairs of parapodia, living as commensals or (endo)parasites mostly on crinoid and ophiuroid echinoderms. They are generally considered aberrant annelids, possibly phyllodocidan polychaetes. A phylogenetic analysis of 18S and 28S ribosomal DNA sequence data of Myzostoma glabrum, together with 60 morphological, developmental, ultrastructural, and life-history characters, is presented to show that myzostomes are a sister group of the Cycliophora, closely related to the rotifer-acanthocephalan clade (=Syndermata). Myzostomes and syndermates share predominantly the highly derived spermatozoa with anteriorly directed flagella (cycliophoran sperm is insufficiently known). The myzostome-cycliophoran-syndermate clade, accommodated within the Platyzoa (including Platyhelminthes s. str., Gastrotricha, Gnathostomulida, Syndermata, Cycliophora, and Myzostomida), is strongly supported by most analyses, regardless of alignment parameters, character combinations and weighting, species sampling, and tree-building methods. The new name Prosomastigozoa ("forward-flagellar animals") is proposed for the group including three phyla (Cycliophora, Myzostomida, and Syndermata).

Phylogeny of Maculinea blues (Lepidoptera: Lycaenidae) based on morphological and ecological characters: evolution of parasitic myrmecophily.

A phylogeny of blue butterflies of the genus Maculinea and related genera (Lycaenidae) is proposed, based on 91 morphological and ecological characters. The resulting tree shows that: (1) Phengaris is a derived group nested within Maculinea; (2) the Maculinea-Phengaris clade is probably nested within Glaucopsyche; (3) there are three well supported groups within the Maculinea-Phengaris clade: (alcon group ((teleius group) (arion-Phengaris group))). Some species (M. alcon, M. arionides) appear to be non-monophyletic and require reclassification. The two alternative strategies of parasitic myrmecophily in the Maculinea-Phengaris clade, viz., "predatory" and "cuckoo", seem to be derived characters of the alcon group, and of the teleius and arion-Phengaris groups, respectively. The common ancestor of Maculinea used dorsal nectary organ secretions for ant attraction, while this trait was reduced in the ancestor of the alcon group and in M. nausithous (of the teleius group). The three recent Maculinea lineages utilize taxonomically diverse host plants, the asterid families Gentianaceae (alcon and arion-Phengaris groups), Lamiaceae (arion-Phengaris group), Campanulaceae (arion-Phengaris group), and the rosid family Rosaceae (teleius group).

Phylogeny of the Metazoa Based on Morphological and 18S Ribosomal DNA Evidence.

Cladistic analysis of traditional (i.e. morphological, developmental, ultrastructural) and molecular (18S rDNA) data sets (276+501 informative characters) provides a hypothesis about relationships of all meta-zoan higher taxa. Monophyly of Metazoa, Epith-eliozoa (= -03non-Porifera), Triploblastica, Mesozoa, Eutriploblastica (=Rhabditophora+Catenulida+"higher triploblasts"=Neotriploblastica, including Xeno- turbellida and Gnathostomulida), Rhabditophora, Syndermata (="Rotifera"+Acanthocephala), Neotrichozoa (=Gastrotricha+Gnathostomulida), Nematozoa (=Nematoda+Nematomorpha), Panarthropoda (=Onychophora+Tardigrada+ Arthropoda), Cephalorhyncha, Deuterostomia, Ambulacralia (=Hemichordata+Echinodermata), Chordata, Phoronozoa (=Phoronida+"Brachiopoda"), Bryozoa, Trochozoa (=Eutrochozoa+Entoprocta+ Cycliophora), Eutrochozoa, and Chaetifera (=Annelida+ Pogonophora+Echiura) is strongly supported. Cnidaria (including Myxozoa), Ecdysozoa (=Cepha- lorhyncha + Nematozoa + Chaetognatha + Panarthropoda), Eucoelomata (=Bryozoa+Phoronozoa+Deuterostomia+Trochozoa, possibly including also Xenoturbellida), and Deuterostomia+Phoronozoa probably are monophyletic. Most traditional "phyla" are monophyletic, except for Porifera, Cnidaria (excluding Myxozoa), Platyhelminthes, Brachiopoda, and Rotifera. Three "hot" regions of the tree remain quite unresolved: basal Epitheliozoa, basal Triploblastica, and basal Neotriploblastica. A new phylogenetic classification of the Metazoa including 35 formally recognized phyla (Silicispongea, Calcispongea, Placozoa, Cnidaria, Ctenophora, Acoela, Nemertodermatida, Orthonecta, Rhombozoa, Rhabditophora, Catenulida, Syndermata, Gnathostomulida, Gastrotricha, Cephalorhyncha, Chaetognatha, Nematoda, Nematomorpha, Onychophora, Tardigrada, Arthropoda, Echinodermata, Hemichordata, Chordata, Phoronozoa, Bryozoa s. str., Xenoturbellida, Entoprocta, Cycliophora, Nemertea, Mollusca, Sipuncula, Echiura, Pogonophora, and Annelida) and few i ncertae sedis g roups (e.g. Myzostomida and Lobatocerebromorpha) is proposed.

The telomere repeat motif of basal Metazoa.

In most eukaryotes the telomeres consist of short DNA tandem repeats and associated proteins. Telomeric repeats are added to the chromosome ends by telomerase, a specialized reverse transcriptase. We examined telomerase activity and telomere repeat sequences in representatives of basal metazoan groups. Our results show that the 'vertebrate' telomere motif (TTAGGG)( n ) is present in all basal metazoan groups, i.e. sponges, Cnidaria, Ctenophora, and Placozoa, and also in the unicellular metazoan sister group, the Choanozoa. Thus it can be considered the ancestral telomere repeat motif of Metazoa. It has been conserved from the metazoan radiation in most animal phylogenetic lineages, and replaced by other motifs-according to our present knowledge-only in two major lineages, Arthropoda and Nematoda.

The evolutionary origin of insect telomeric repeats, (TTAGG)n.

The (TTAGG)n sequence is supposed to be an ancestral DNA motif of telomeres in insects. Here we examined the occurrence of TTAGG telomeric repeats in other arthropods and their close relatives by Southern hybridization of genomic DNAs and fluorescence in-situ hybridization (FISH) of chromosomes with (TTAGG)n probes or, alternatively, with the 'vertebrate' telomeric probe, (TTAGGG)n. Our results show that the (TTAGG)n motif is conserved in entognathous hexapods (Diplura and Collembola), crustaceans (Malacostraca, Branchiura, Pentastomida, and Branchiopoda), myriapods (Diplopoda and Chilopoda), pycnogonids, and most chelicerates (Palpigradi, Amblypygi, Acari, Opiliones, Scorpiones, Pseudoscorpiones, and Solifugae) but not in spiders (Araneae). The presence of TTAGG repeats in these groups suggests that the sequence is an ancestral motif of telomeres not only in insects but in Arthropoda. We failed, however, to detect the TTAGG repeats in close relatives of the arthropods, Tardigrada and Onychophora. But while Onychophora had the 'vertebrate' (TTAGGG)n motif instead, the Tardigrada did not. The (TTAGG)n motif probably evolved from the (TTAGGG)n motif. Based on our and compiled data, we presume that the 'vertebrate' motif (TTAGGG)n is an ancestral motif of telomeres in bilaterian animals and possibly also in the superclade including animals, fungi and amoebozoans.

Phylogeny of Lasius ants based on mitochondrial DNA and morphology, and the evolution of social parasitism in the Lasiini (Hymenoptera: Formicidae).

Phylogeny of ants of the tribe Lasiini (Lasius, Acanthomyops, Prenolepis, Euprenolepis, Paratrechina, Pseudolasius, and Myrmecocystus) was analysed using 81 morphological, ecological, and behavioural characters (for 41 species) and mitochondrial DNA sequences (COI, COII, tRNA-Leu; for 19 species). The free-living subgenus Lasius s. str. is paraphyletic with respect to the rest of genus; the traditional "genus" Acanthomyops should be considered a part of Lasius s. lat.; free-living subgenus Cautolasius is a member of the clade of socially parasitic Lasius ants (=Chtonolasius+Acanthomyops+Austrolasius+Dendrolasius). The tree topology is congruent with two alternative scenarios of origin of the temporary social parasitism: (i) a single origin of the parasitic strategy in a derived subclade of Lasius and a secondary loss of this trait in Cautolasius, (ii) a parallel origin of the social parasitism within the clade of hypogeic Lasius ants (in Chtonolasius, and in Acanthomyops+Dendrolasius+Austrolasius). Emery's rule in the strict sense does not apply to this group because most parasites exploit any ecologically available, even phylogenetically distant host species. The parasitic strategy in Lasius could have originated from the aggressive interactions between cofounding queens during pleometric colony founding and/or from the secondary queen adoption.

Phylogeny and biogeography of Triatominae (Hemiptera: Reduviidae): molecular evidence of a New World origin of the Asiatic clade.

The most representative sample of molecular data, especially 16S and 12S rDNAs, is used to study the phylogeny and evolution of 57 species of three tribes, Rhodniini, Linshcosteini, and Triatomini, of the subfamily Triatominae. For the first time both New World and Old World species are brought together in a single phylogenetic analysis. Maximum-parsimony and distance estimation place both the Asiatic representatives, Linshcosteus and Triatoma rubrofasciata, as sister groups. The Linshcosteus-T. rubrofasciata clade nests firmly within Triatomini, in most analyses branching as a basalmost lineage, thus supporting a monophyletic origin of Triatominae. A paraphyly of "Triatoma" with respect to Linshcosteus, Dipetalogaster, Eratyrus, and Panstrongylus and the paraphyly of "Rhodnius" with respect to Psammolestes is observed in most of the analyses. Reinterpretation of triatomine biogeography points to the origin of Triatominae in northern areas of South America, in Central America, or in the southern region of North America. A few taxonomic changes are proposed: (1) reinclusion of Linshcosteus in Triatomini, (2) inclusion of Psammolestes in Rhodnius, (3) elevation of the "T. flavida complex" to the full genus Nesotriatoma (including N. flavida, N. bruneri, and N. obscura), (4) inclusion of the "T. spinolai complex" in Mepraia (including M. spinolai, M. gajardoi, M. eratyrusiformis, and M. breyeri), and (5) inclusion of "T." dimidiata in Meccus (M. dimidiatus).