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(1) Unravelling the molecular basis underlying major evolutionary transitions can shed light on how complex phenotypes arise. The evolution of eusociality, a major evolutionary transition, has been demonstrated to be accompanied by enhanced gene regulation. Numerous pieces of evidence suggest the major impact of transposon insertion on gene regulation and its role in adaptive evolution. Transposons have been shown to be play a role in gene duplication involved in the eusocial transition in termites. However, evidence of the molecular basis underlying the eusocial transition in Blattodea remains scarce. Could transposons have facilitated the eusocial transition in termites through shifts of gene expression? (2) Using available cockroach and termite genomes and transcriptomes, we investigated if transposons insert more frequently in genes with differential expression in queens and workers and if those genes could be linked to specific functions essential for eusocial transition. (3) The insertion rate of transposons differs among differentially expressed genes and displays opposite trends between termites and cockroaches. The functions of termite transposon-rich queen- and worker-biased genes are related to reproduction and ageing and behaviour and gene expression, respectively. (4) Our study provides further evidence on the role of transposons in the evolution of eusociality, potentially through shifts in gene expression.

International audience; Functionally and evolutionarily distinct species have traits or an evolutionary history that are shared by few others in a given set, which make them priority species for biodiversity conservation. On islands, life in isolation has led to the evolution of many distinct forms and functions as well as to a high level of endemism. The aim of this study is to assess the evolutionary and functional distinctiveness of insular monocotyledons and their distribution across 126 islands worldwide. We show that evolutionary and functional distinctiveness are decoupled but that both are higher on islands than on continental areas. Anagenesis on islands followed by extinctions and/or diversification on the mainland may have led to highly evolutionarily distinct species while functionally distinct species may have arisen from ecological niche shift or niche expansion. Insular endemic species with high evolutionary distinctiveness but not with high functional distinctiveness are significantly range-restricted compared to less distinct species, possibly indicating differences in dispersal potential. By showing that distinctiveness is high on islands and that the most distinct species are range-restricted, our study has important conservation implications. Indeed, islands are among the most threatened systems of the world, and extinctions of the most distinct species could lead to significant loss of phylogenetic and functional diversity.

Deciphering the timing and tempo of lineage diversification of organisms has greatly benefited from advances in Bayesian phylogenetic analyses using morphological data. Those advances, however, have not been used for termites despite a rich fossil record. Here, we estimate divergence times for living and fossil termites using the fossilized birth–death (FBD) process on a previously published morphological matrix expanded with two new fossils that we describe (see Appendices 1 & 2). Those fossils, based on soldier specimens, are the ‘mid’-Cretaceous mastotermitid Milesitermesengeligen. et sp. nov., and the Middle Eocene Reticulitermesgrimaldiisp. nov. The latter is the oldest occurrence of a Rhinotermitidae soldier and the first termite soldier described from Baltic amber. Our dating estimates provide new stem- and crown-ages for termites, suggesting older ages than previously thought for several lineages. Importantly, crown-Isoptera—and therefore eusociality—may have arisen ~200 Ma. We conclude with further directions to keep improving our understanding of the timing of differentiation in termites.Page 2 of 77Systematic Entomology

The past diversity of Isoptera is relatively poorly documented. Many early-diverging families are only represented today by relicts of their Mesozoic and Cenozoic richness. Therefore, the onset of their evolutionary history and the transitions between families, or even between subsocial and eusocial ways of life, remain difficult to decipher and require additional fossil occurrences. Here, we report the oldest worker/pseudergate trapped in amber and a new Mastotermitidae, both from Hkamti amber. We document a diverse assemblage of species representing early-diverging families from the ‘Mid’-Cretaceous of Myanmar, including two new genera and four new species in as many different genera: Anisotermes bourguignoni sp. nov., Longitermes pulcher gen. et sp. nov., Magnifitermes krishnai gen. et sp. nov. and Mastotermes myanmarensis sp. nov. These descriptions provide significant morphological evidence to discuss the placement of the genus Anisotermes, confidently place the new genera and confirm the monophyly of Mastotermitidae. The diversity of Cretaceous isopterans, in light of the biology of their extant representatives, is used to discuss palaeoecological implications and highlights the radiation of early diverged Isoptera in the complex Cretaceous ecosystem. The validity of the species Meiatermes cretacicus is discussed.

The geometric mean length (GML) is proposed as a new statistic aimed at describing the evenness of character changes on a tree for a given set of character optimizations. It is the geometric mean of the number of steps on each branch of the tree, varying between a maximum value when all branch lengths are equal, and a minimum value when all branches but one have only one character step. It can be scaled according to its theoretical maximum value, thus indicating a relative GML that allows a comparison of the evenness of character steps between different tree topologies. � The Willi Hennig Society 2004.

In forest fragmentation studies, low specific richness in small fragments and community nestedness are usually considered to result from species loss. However, except in the case of fragmentation experiments, these studies cannot distinguish between original low richness and secondary species loss, or between original high richness and secondary colonizations in fragments. To distinguish between these possibilities is a matter of historical inference for which phylogenetic algorithms are designed. The methods of phylogenetic analysis, and especially parsimony analysis, can be used to find a tree of relationships between communities from different forest fragments, taking the presence or absence of species among different communities as characters. Parsimony analysis searches if species subsets can be classified in a nested hierarchy, and also establishes how the communities evolved, polarizing species changes into either extinctions or colonizations. By re-analyzing two classical studies in this new and powerful way, we demonstrate that the differences between fragments and large continuous forests cannot be attributed to species loss in all cases, contrary to expectations from models. © The Willi Hennig Society 2005.

In comparative biology, character observations initially separate similar and dissimilar characters. Only similar characters are considered for phylogeny reconstruction; their homology is attested in a two-step process, firstly a priori of phylogeny reconstruction by accurate similarity statements, and secondly a posteriori of phylogeny analysis by congruence with other characters. Any pattern of non-homology is then a homoplasy, commonly, but vaguely, associated with “convergence”. In this logical scheme, there is no way to analyze characters which look similar, but cannot meet usual criteria for homology statements, i.e., false similarity detected a priori of phylogenetic analysis, even though such characters may represent evolutionarily significant patterns of character transformations. Because phylogenies are not only patterns of taxa relationships but also references for evolutionary studies, we propose to redefine the traditional concepts of parallelism and convergence to associate patterns of non-homology with explicit theoretical contexts: homoplasy is restricted to non-similarity detected a posteriori of phylogeny analysis and related to parallelism; non-similarity detected a priori of phylogenetic analysis and necessarily described by different characters would then correspond to a convergence event s. str. We propose to characterize these characters as heterologous (heterology). Heterology and homoplasy correspond to different non-similarity patterns and processes; they are also associated with different patterns of taxa relationships: homoplasy can occur only in non-sister group taxa; no such limit exists for heterology. The usefulness of these terms and concepts is illustrated with patterns of acoustic evolution in ensiferan insects. © The Willi Hennig Society 2005.

A character of special interest in evolutionary studies is usually optimized on a phylogenetic tree, with or without the outgroups employed in that analysis. Both practices are never justified and look like arbitrary choices. Focusing on one example, we draw the conclusion that authors retain or remove outgroups depending on the way these outgroups sample the diversity of states of the character(s) of special interest. The topology without outgroups is often used by authors when different outgroup taxa nonexhaustively sample the different states of the character of interest outside of the ingroup. This can make the analysis incoherent, because its different steps are not based on the same data matrix (outgroups are removed in the last step). It can provide several incoherent and possibly different patterns for a same character of interest, one issuing from the first step of phylogeny construction and the other resulting from the a posteriori optimization on the truncated topology. Phylogenetic analyses should be designed to minimize this problem, selecting outgroup and ingroup taxa whose diversity of character states is needed for reconstructing the evolutionary history of the character of interest. � The Willi Hennig Society 2004.

An increasing variety of extrinsic traits are used in comparative studies aimed at testing evolutionary hypotheses. After briefly reviewing the relevant literature, it appears that three different problems are implied by this trend. Some extrinsic traits are only surrogates for phenotypic traits, and should be redefined to better fit the requisites for phylogenetic analysis, such as selective regimes and extinction risks. Some others are already adequately defined and cannot be made less extrinsic, such as taxon age, geographical distribution, associates (parasites, symbionts, etc.), and bioclimatic modelled niches. Because they are not heritable, they should not be analysed by optimization onto a tree, but are better considered in sister-group comparisons or within a reconciliation procedure, as already done for areas of biogeography. © The Willi Hennig Society 2010.

New Caledonia was, until recently, considered an old continental island harbouring a rich biota with outstanding Gondwanan relicts. However, deep marine sedimentation and tectonic evidence suggest complete submergence of the island during the latest Cretaceous to the Paleocene. Molecular phylogenies provide evidence for some deeply-diverging clades that may predate the Eocene and abundant post-Oligocene colonisation events. Extinction and colonization biases, as well as survival of some groups in refuges on neighbouring paleo-islands, may have obscured biogeographic trends over long time scales. Fossil data are therefore crucial for understanding the history of the New Caledonian biota, but occurrences are sparse and have received only limited attention. Here we describe five exceptional fossil assemblages that provide important new insights into New Caledonia’s terrestrial paleobiota from three key time intervals: prior to the submersion of the island, following re-emergence, and prior to Pleistocene climatic shifts. These will be of major importance for elucidating changes in New Caledonia’s floristic composition over time.

Les collections d’Histoire naturelle doivent ajouter aux usages traditionnels taxonomiques les utilisations innovantes liées à des problématiques actuelles (changement global, nouvelles ressources naturelles avec le biomimétisme, etc.). Ces nouvelles utilisations sont possibles grâce au statut matériel des collections contenant des spécimens et leurs liens avec des informations numériques.

International audience; L’informatisation des collections d’histoire naturelle et leur agrégation dans des portails globaux donnent un accès sans précédent à la richesse des collections. De la gestion des collections à l’analyse scientifique, le défi consiste à s’approprier ce changement d’échelle en regard de la quantité et de la nature des données pour répondre à de nouvelles questions dans une dynamique de science ouverte.

International audience; There is an error in legend of Figure 3, names of the butterfly species have been swapped and therefore do not correspond to the photos of these species.; Une erreur s’est glissée dans la légende de la Figure 3, avec une interversion des noms des espèces de papillons qui ne correspondent donc pas aux photos de ces espèces.

International audience; Phylogenomics seeks to use next‐generation data to robustly infer an organism's evolutionary history. Yet, the practical caveats of phylogenomics motivate investigation of improved efficiency, particularly when quality of phylogenies are questionable. To achieve improvements, one goal is to maintain or enhance the quality of phylogenetic inference while severely reducing dataset size. We approach this by assessing which kinds of loci in phylogenomic alignments provide the majority of support for a phylogenetic inference of cockroaches in Blaberoidea. We examine locus substitution rate, saturation, evolutionary divergence, rate heterogeneity, stabilizing selection, and a priori information content as traits that may determine optimality. Our controlled experimental design is based on 265 loci for 102 blaberoidean taxa and 22 outgroup species. Loci with high substitution rate, low saturation, low sequence distance, low rate heterogeneity, and strong stabilizing selection derive more support for phylogenetic relationships. We found that some phylogenetic information content estimators may not be meaningful for assessing information content a priori. We use these findings to design concatenated datasets with an optimized subsample of 100 loci. The tree inferred from the optimized subsample alignment was largely identical to that inferred from all 265 loci but with less evidence of long branch attraction, improved statistical support, and potential 4‐6x improvements to computation time. Supported by phylogenetic and morphological evidence, we erect three newly named clades (Anallactinae Evangelista & Wipfler subfam. nov., Orkrasomeria tax. nov. Evangelista, Wipfler, & Béthoux and Hemithyrsocerini Evangelista tribe nov.) and propose other taxonomic modifications. The diagnosis of Pseudophyllodromiidae Grandcolas, 1996 is modified to accommodate Anallactinae and Pseudophyllodromiinae Vickery & Kevan, 1983. The diagnosis of Ectobiidae Brunner von Wattenwyl, 1865 is modified to add novel morphological characters.

Variations of speciation and extinction rates determine the fate of clades through time. Periods of high diversification and extinction (possibly mass-extinction events) can punctuate the evolutionary history of various clades, but they remain loosely defined for many biological groups, especially nonmarine invertebrates like insects. Here, we examine whether the cockroaches, mantises and termites (altogether included in Dictyoptera) have experienced episodic pulses of speciation or extinction and how these pulses may be associated with environmental fluctuations or mass extinctions. We relied on molecular phylogeny and fossil data to shed light on the times and rates at which dictyopterans diversified. The diversification of Dictyoptera has alternated between (i) periods of high diversification in the late Carboniferous, Early-Middle Triassic, Early Cretaceous and middle Palaeogene, and (ii) periods of high extinction rates particularly at the Permian-Triassic boundary, but not necessarily correlated with the major global biodiversity crises as in the mid-Cretaceous. This study advocates the importance of analyzing, when possible, both molecular phylogeny and fossil data to unveil diversification and extinction periods for a given group. The causes and consequences of extinction must be studied beyond mass-extinction events alone to gain a broader understanding of how clades wax and wane.

Insects appeared more than 400 million years ago and they represent the richest and most diverse taxonomic group with several million species. Yet, under the combined effect of the loss of natural habitats, the intensification of agriculture with massive use of pesticides, global warming and biological invasions, insects show alarming signs of decline. Although difficult to quantify, species extinction and population reductions are confirmed for many ecosystems. This results in a loss of services such as the pollination of plants, including food crops, the recycling of organic matter, the supply of goods such as honey and the stability of food webs. It is therefore urgent to halt the decline of Insects. We recommend implementing long-term monitoring of populations, tackling the causes of insect decline by reducing the use of synthetic insecticides, preserving natural habitats, and reinventing a positive relationship between humans and insects.Apparus il y a plus de 400 millions d’années, les Insectes représentent le groupe taxonomique le plus riche et diversifié, avec plusieurs millions d’espèces. Sous l’effet de la disparition des habitats, de l’intensification de l’agriculture avec l’usage massif des pesticides, du réchauffement climatique et des invasions biologiques, les Insectes montrent des signes alarmants de déclin. Bien que difficiles à quantifier, la disparition des espèces et la réduction de leurs populations sont avérées et communes à de nombreux écosystèmes. Elles se traduisent par une perte des services rendus, comme la pollinisation des plantes vivrières, le recyclage de la matière organique, la fourniture de biens comme le miel, et l’équilibre des réseaux trophiques. Il est donc urgent de freiner le déclin des Insectes. Pour cela, il faut mettre en œuvre des suivis à long terme des populations, réduire l’usage des insecticides de synthèse, préserver les habitats naturels, et réinventer la relation de l’Homme à l’Insecte en revalorisant son image et ses usages.

There are several ways to evaluate Biodiversity, which is a multi-level concept with multiple purposes. Each consideration of this concept generally involves the prism of a scientific discipline, a study level or a specific purpose. Thus, scientists focus sometimes on intraspecific diversity, sometimes on interspecific diversity, or even on the diversity that can be studied at the level of ecosystems, etc. Disciplines usually concentrate on their study subject, such as genomics on diversity within genomes or population biology on diversity within populations.

The original efforts of early naturalists are now placed in another context. Instead of adding lots of particulars to a catalogue of Life, the idea is now to contribute to an organized picture: comparative biology and general biology have merged. Systematics or the related sciences of Biodiversity employ a reasoning analogous to the one followed by early general biology when it separated from natural history and activities associated with collections in the early XXth century. There is a presumption one is already knowledgeable about laws or general patterns when studying biological processes or adding species: both contribute to the general picture. As a consequence of this state of mind, many authors do not feel the need for saving specimens. However, saving specimens is not only a way to keep records in a world which is still being discovered, it is also a very efficient way to store information and to allow one to return to the original specimens, thus generating additional data to answer other questions. We must be fully aware of both the rationale but also the present-day state of mind, in order to keep our motivation in the pursuit of an adequate sampling of Biodiversity.

International audience; To better understand insect evolution, fossils – mainly known by their wings – must be used as terminals in phylogenetic analyses. Such analyses are, however, rarely performed because of a lack of consensus on the homology of venation in insects. Authors do not agree with current concept on the exact number and the identity of the main veins. Here, we confirm the presence, questioned since the early twentieth century, of an independent main postcubital vein (PCu) between the cubital and anal veins (29 fossil and extant examined orders, >85% of observed insects). The vein PCu corresponds to the so-called vein 1A or first anal vein. It is easily identified by the unique shape of its bulla. It may have several branches, and be partially fused with the cubital and anal veins. Once the PCu vein identified, we reconsidered as an example the particular case of the Phasmatodea, showing that extant stick insects have a unique venation among insects, with a reduced median vein, and a simple cubital vein, adjacent or fused to the PCu. This study is a new approach towards resolving wing vein homology issues, crucial for future large-scale phylogenetic analyses in insects combining extant and extinct taxa.

International audience; Biology has already experienced great divides that decreased its global coherence and its ability to answer important scientific and societal concerns. For example in the XXth century, the so-called "Life Sciences" developed remarkably in comparison to Natural History sciences. This way, the approaches on model organisms dominated or prevented other approaches from being carried out on more diverse organisms, which may have given a misleading feeling of generality for the results obtained. Another great divide is at risk of developing now with the rise of what could be called "Digital Biology," separating from other "material-based" approaches in its tendency to consider digital data only. Some biologists adopt a somewhat essentialist view of species and DNA, considering that enough knowledge is now accumulated, and that species records can be kept and saved as digital data only (Grandcolas 2017). Examples of this include occurrence records without specimens or auxiliary documents, taxonomic descriptions based on photographs, DNA sequences without vouchers, and, lastly, DNA sequences without taxonomic names. This tendency puts at risk the sustainability, growth, and coherence of biological knowledge that is organized in a system wherein all data and notions are connected via specimens, with names and sequences being a retrieval means (Troudet et al. 2018). This tendency also ignores the robust foundation of biology, the data of which are linked to collections, vouchers, and stocks. The foundation of physical specimens exists for data concerning any live beings, be they rare wild species or selected lines of model organisms. There are now many calls for open and FAIR science, with results, methods, tools, and data not only findable, accessible, and interoperable but also re-usable. More than FAIR and digitally reusable, data need to be sustainable. It is needed that their meaning and significance can be re-analysed, re-interpreted by going back as far as possible to material vouchers. We urge then scientists to consider this question by providing all necessary material elements to make open and FAIR data sustainable as well.

The diversity of insects is often explained as a product of major radiations, triggered by remarkable adaptations that allowed them to exploit different environments and to accompany the rise of flowering plants . A significant part of insect diversity results however from allopatric speciation with niche conservatism that exposed species to different conditions and stimulated adaptive divergence. We demonstrated that for several groups of Insects (cockroaches, crickets and grasshoppers) in the island of New Caledonia. Since Darwin and Wallace, islands are considered as laboratories of evolution, being closed systems of manageable size. New Caledonia is especially interesting in this respect, according to unique characteristics. Being the oldest oceanic island in the world and quite isolated from continents, biological evolution occurred there in situ during long periods. As a tropical and medium-sized island harboring a very rich biodiversity, it also offered facilities to study many different evolutionary questions. New Caledonia (hereafter NC) has thus the best characteristics as a model system, allowing testing very diverse evolutionary assumptions with limited efforts and infrastructures. Unfortunately, these amazing geographical characteristics have also constrained the scientific study of NC until now, especially because of its isolation from large academic centers. Establishing NC as a modern oceanic model system resulted however from our work, later than the 1990s. Before, NC had the reputation of an amazingly old Gondwanan place and was intuitively considered as a continental fragment. If so, its usefulness as a model system to study evolution would have been limited since the biota of continental islands (e.g., Madagascar or New Zealand) are a complicated mix of organisms dating back to the separation with neighboring continental territories or having colonized the island by dispersal. In most of these cases, it happened difficult to distinguish between both these different components and to examine evolutionary assumptions that require a reference dating point. The reasons why NC was traditionally considered a continental territory were the age of its deep geological basement and the local occurrence of relict species. In agreement with this common assumption, the NC geological deep basement is ancient and predates Gondwanan breakup. But this basement has been submitted to important environmental disturbances because of the island location at the limit between two tectonic plates. Actually, the island has been submerged twice for a long time at Paleocene and Eocene epochs and only emerged around 37 ± 3 Ma. This geological background was in need of independent testing with biological studies. We thus built multiple molecular phylogenetic trees of different groups of organisms, dated with probabilistic methods and external calibration points. A first review [1] and a more recent meta-analysis [2] of these studies showed that most groups colonized NC and diversified just after 37 My, confirming the geological scenario of recent terrestrial emergence. However, a few local species belong to groups that were dated much older than 37 My, representing true relicts, i.e. recent species that remained from old clades [3] . These old clades can only be assumed to have been ancestrally present in the region, colonizing NC after its emergence and going extinct in other territories, either drowned islands or mutated continental ecosystems. These different results strongly indicated that NC is an oceanic island, even if very old–actually the oldest one in the world–and that its local biota dated back to island emergence. Relicts are fascinating species, unfortunately too sparsely known after the major extinction of their relatives to support any robust biogeographic scenario. Fossil data are absolutely needed to assess the evolutionary history of these taxa without speculation. Setting up this biogeographic scenery has allowed one to properly conduct speciation studies by inferring the age and the ancestral phenotypic characters of local lineages. We did that in several groups of insects, cockroaches, crickets, and grasshoppers , and we showed that speciation occurred mainly in relation to orography, in allopatry and with niche conservatism. Closely related species occurred as narrow endemics in the same habitats of neighboring areas, mainly on adjacent small mountains. Sympatry , when observed, was inferred to be secondarily caused by the increase of distribution area of older species. Even if most speciation events seemed to have occurred without any important evolutionary change, some adaptive shifts have been detected in several cases, from different food plants on metalliferous soils to different habitats in the forest understory . The major conclusion that can be drawn from high speciation rate and narrow endemicity in New Caledonia is that speciation went before, not always together with adaptive divergence. Here we offer both a new and powerful natural laboratory of evolution, calibrated in space and time, and a model of speciation where niche conservatism is the engine for adaptive divergence.

At their early age, a large proportion of island pools were a partial sampling of mainland pools whatever islands are oceanic or fragments of the mainland. Through time, colonization, diversification, extinctions, have deeply transformed insular and continental communities and therefore the degree to which they share species. We studied the relative importance of these mechanisms by looking at the shared evolutionary history between species pools on islands and continents. Indeed, most of these mechanisms are not neutral regarding phylogeny but are linked to species evolutionary relationships. We measured the phylogenetic divergence between continental and insular monocot communities through metrics of beta Mean Pairwise Distance and beta Mean Nearest Taxon Distance. We first tested the influence of spatial and environmental distance to the continent, two main factors of divergence, but whose explanatory power in a phylogenetic context was still unclear. We showed that both dispersal and enviromental filtering were important to explain divergence, although species that could pass these filters were not phylogenetically clustered. There was however a clear distinction between oceanic and continental islands: a stable climate in the latters was key to the survival of the original biota leading to a high proportion of shared lineages between the mainland and islands. But distance to the continent was only part of the story, we investigated additionnal mechanisms of phylogenetic divergence through their relation to island features and community structure. This showed that the most divergent islands occurred in the tropics and that processes of persistence of original species, diversification in remote archipelagos, neutral colonization on easy-to-reach islands, turnover, and high speciation rates may have driven phylogenetic divergence at a world scale. This study showed how phylogenetic approaches may explain how divergence, or similarity may have arisen and provide new insights in the continental origin of plant diversity on islands.

Phylogenomics seeks to use next-generation data to robustly infer an organism’s evolutionary history. Yet, the practical caveats of phylogenomics motivates investigation of improved efficiency, particularly when quality of phylogenies are questionable. To achieve improvements, one goal is to maintain or enhance the quality of phylogenetic inference while severely reducing dataset size. We approach this goal by designing an optimized subsample of data with an experimental design whose results are determined on the basis of phylogenetic synecdoche − a comparison of phylogenies inferred from a subsample to phylogenies inferred from the entire dataset. We examine locus mutation rate, saturation, evolutionary divergence, rate heterogeneity, selection, and a priori information content as traits that may determine optimality. Our controlled experimental design is based on 265 loci for 102 blaberoidean cockroaches and 22 outgroup species. High phylogenetic utility is demonstrated by loci with high mutation rate, low saturation, low sequence distance, low rate heterogeneity, and low selection. We found that some phylogenetic information content estimators may not be meaningful for assessing information content a priori. We use these findings to design concatenated datasets with an optimized subsample of 100 loci. The tree inferred from the optimized subsample alignment was largely identical to that inferred from all 265 loci but with less evidence of long branch attraction and improved statistical support. In sum, optimized subsampling can improve tree quality while reducing data collection costs and yielding 4-6x improvements to computation time in tree inference and bootstrapping.

International audience; The concept of biological diversity, or biodiversity, is at the core of evolutionary and ecological studies. Many indices of biodiversity have been developed in the last four decades, with species being one of the central units of these indices. However, evolutionary and ecological studies need a precise description of species' characteristics to best quantify inter-species diversity, as species are not equivalent and exchangeable. One of the first concepts characterizing species in biodiversity studies was abundance-based rarity. Abundance-based rarity was then complemented by trait-and phylo-based rarity, called species' trait-based and phylogenetic originalities, respectively. Originality, which is a property of an individual species, represents a species' contribution to the overall diversity of a reference set of species. Originality can also be defined as the rarity of a species' characteristics such as the state of a functional trait, which is often assumed to be represented by the position of the species on a phylogenetic tree. We review and compare various approaches for measuring originality, rarity and diversity and demonstrate that (i) even if attempts to bridge these concepts do exist, only a few ecological and evolutionary studies have tried to combine them all in the past two decades; (ii) phylo-and trait-based diversity indices can be written as a function of species rarity and originality measures in several ways; and (iii) there is a need for the joint use of these three types of indices to understand community assembly processes and species' roles in ecosystem functioning in order to protect biodiversity efficiently.

International audience

Although acoustic signals are important for communication in many taxa, signal propagation is affected by environmental properties. Strong environmental constraints should drive call evolution, favoring signals with greater transmission distance and content integrity in a given calling habitat. Yet, few empirical studies have verified this prediction, possibly due to a shortcoming in habitat characterization, which is often too broad. Here we assess the potential impact of environmental constraints on the evolution of advertisement call in four groups of torrent-dwelling frogs in the family Ranidae. We reconstruct the evolution of calling site preferences, both broadly categorized and at a finer scale, onto a phylogenetic tree for 148 species with five markers (∼3600 bp). We test models of evolution for six call traits for 79 species with regard to the reconstructed history of calling site preferences and estimate their ancestral states. We find that in spite of existing morphological constraints, vocalizations of torrent-dwelling species are most probably constrained by the acoustic specificities of torrent habitats and particularly their high level of ambient noise. We also show that a fine-scale characterization of calling sites allows a better perception of the impact of environmental constraints on call evolution.