Revisiting Nature's "Unifying Patterns": A Biological Appraisal

Effective bioinspiration requires dialogue between designers and biologists, and this dialogue must be rooted in a shared scientific understanding of living systems. To support learning from "nature's overarching design lessons" the Biomimicry Institute has produced ten "Unifying Patterns of Nature". These patterns have been developed to engage with those interested in finding biologically inspired solutions to human challenges. Yet, although well-intentioned and appealing, they are likely to dishearten biologists. The aim of this paper is to identify why and propose alternative principles based on evolutionary theory.

Eusocial Transition in Blattodea: Transposable Elements and Shifts of Gene Expression

(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.

Incrementing and clarifying the diversity and early evolution of termites (Blattodea: Isoptera)

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.

Termite Valkyries: Soldier-Like Alate Termites From the Cretaceous and Task Specialization in the Early Evolution of Isoptera

In several insect eusocial lineages, e.g., some aphids, thrips, ants, some stingless bees, and termites, task specialization is brought to its climax with a sterile soldier caste solely devoted to colony defense. In Isoptera, while the reproductives are defenseless, the soldiers have unique morpho-physiological specializations whose origin and evolution remain unresolved. Here we report on two instances of Cretaceous fossil termite reproductives belonging to different families († Valkyritermes inopinatus gen. et sp. nov. and an unpublished specimen from the Crato Formation), with intriguing phragmotic soldier-like heads and functional wings. These individuals, herein called Valkyries, are the first termite reproductives known with defensive features and suggest that phragmosis arose at least in the Early Cretaceous. Valkyries resemble modern neotenic soldiers except for their complete wings. Their discovery supports the hypothesis that the division between reproductive (indicated by the winged condition of Valkyries) and defensive tasks (indicated by the phragmotic head) has not always been complete in termite history. We explore two alternative scenarios regarding the origin of Valkyries (i.e., relatively recent and convergent origins vs. plesiomorphic condition) and discuss how they might relate to the development of soldiers. We argue that, in both cases, Valkyries likely evolved to face external threats, a selective pressure that could also have favored the origin of soldiers from helpers. Valkyries highlight the developmental flexibility of termites and illustrate the tortuous paths that evolution may follow.

New fossil discoveries illustrate the diversity of past terrestrial ecosystems in New Caledonia

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.

Insect decline: immediate action is needed

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.

Fossil and phylogenetic analyses reveal recurrent periods of diversification and extinction in dictyopteran insects

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.

Covid-19: natural or anthropic origin?

Viruses similar to the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) have been discovered in bats of the genus Rhinolophus and in the Sunda pangolin, Manis javanica Desmarest, 1822, suggesting that these animals have played a key role in the emergence of the Covid-19 outbreak in the city of Wuhan, China. In this paper, we review the available data for sarbecoviruses (viruses related to SARS-CoV [2002–2003 outbreak] and SARS-CoV-2) to propose all possible hypotheses on the origin of Covid-19, i. e., involving direct transmission from horseshoe bats to humans, indirect transmission via the pangolin or another animal, with interspecies contamination between either wild animals or animals kept in cage. Present evidence indicates that Rhinolophus bats are the natural reservoir of all sarbecoviruses, and that two divergent SARS-CoV-2-like viruses have circulated in southern China (at least in Guangxi and Guangdong provinces) between August 2017 and March 2019 in captive pangolins destined for sale in wildlife markets. We performed a genetic analysis of seven seized pangolins found to be positive for SARS-CoV-2-like virus using mitochondrial DNA sequences extracted from Sequence Reads Archive data. The results reveal that the same SARS-CoV-2-like virus can be found in animals with distinct haplotypes, which means that they were probably captured in different Southeast Asian regions. Our interpretation is that some pangolins were contaminated in captivity (by other pangolins or by another species to be determined), suggesting that illegal trade of living wild mammals is at the origin of the Covid-19 outbreak. To definitely validate this hypothesis, it is however necessary to discover a virus almost identical to SARS CoV-2 (at least 99% of identity) in animals sold in wet markets. Although pangolins are good candidates, other mammals, such as small carnivores, should not be overlooked.

Reconciling the concepts and measures of diversity, rarity and originality in ecology and evolution

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.

New Cockroaches (Dictyoptera: Blattodea) from French Guiana and a Revised Checklist for the Region

Although French Guiana is one of the greatest hotspots of cockroach biodiversity on Earth, there are still undocumented species. From both newly collected and museum specimens, we provide species descriptions for Buboblatta vlasaki sp. nov., Lamproblatta antoni sp. nov., and Euhypnorna bifuscina sp. nov. and report new geographic records for species in the genera Epilampra Burmeister, Euphyllodromia Shelford, Ischnoptera Burmeister, and Euhypnorna Hebard. Finally, we update the checklist of species known from the region to 163 total species records from French Guiana, making it the second greatest hotspot of known cockroach biodiversity on Earth.

The Increasing Disconnection of Primary Biodiversity Data from Specimens: How Does It Happen and How to Handle It?

Primary biodiversity data represent the fundamental elements of any study in systematics and evolution. They are, however, no longer gathered as they used to be and the mass-production of observation-based (OB) occurrences is overthrowing the collection of specimen-based (SB) occurrences. Although this change in practice is a major upheaval with significant consequences in the study of biodiversity, it remains understudied and has not attracted yet the attention it deserves. Analyzing 536 million occurrences from the Global Biodiversity Information Facility (GBIF) mediated data, we show that this spectacular change affects the 24 eukaryote taxonomic classes we targeted: from 1970 to 2016 the proportion of occurrences marked as traceable to tangible material (i.e., SB occurrences) fell from 68% to 18%; moreover, most of those specimen based-occurrences cannot be readily traced back to a specimen because the necessary information is missing. Ethical, practical or legal reasons responsible for this shift are known, and this situation appears unlikely to be reversed. Still, we urge scholars to acknowledge this dramatic change, embrace it and actively deal with it. Specifically, we emphasize why SB occurrences must be gathered, as a warrant to allow both repeating evolutionary studies and conducting rich and diverse investigations. When impossible to secure, voucher specimens must be replaced with OB occurrences combined with ancillary data (e.g., pictures, recordings, samples, DNA sequences). Ancillary data are instrumental for the usefulness of biodiversity occurrences and we show that, despite improving technologies to collate them, they remain rarely shared. The consequences of such a change are not yet clear but we advocate collecting material evidence or ancillary data to ensure that primary biodiversity data collected lately do not partly become obsolete when doubtful.

Taxonomic revision of the genus Monastria Saussure, 1864 (Blattodea: Blaberidae, Blaberinae) from the South American Atlantic forest, with the descriptions of five new species

 The genus Monastria Saussure, 1864 includes medium to large sized (40-55 mm) dark brown or black cockroaches found in the understory of the Neotropical Atlantic Forest from the Northeast of Brazil to Paraguay and Argentina. The genus shows evident sexual dimorphism: males are elongated with fully developed wings extending beyond the apex of cerci and females are oval and brachypterous. This study is a revision of the genus with redescription of the three already known species, Monastria biguttata (Thunberg, 1826), Monastria similis (Serville, 1838) and Monastria angulata Saussure, 1864, and description of five new ones, Monastria itubera sp. n. and Monastria itabuna sp. n. from state of Bahia, Monastria cabocla sp. n. from state of Sergipe, Monastria kaingangue sp. n. from state of São Paulo and Monastria sagittata sp. n. from state of Minas Gerais. The morphology of the genus and all species is described in details, including male genitalia. Based on this revision, we proposed a new combination for Hiereoblatta papillosa (Thunberg, 1826) comb. n., excluding it from the genus Monastria. For the first time, the juvenile stages of Monastria are characterized and compared to other genera of Blaberinae of the Atlantic forest. Three determination keys are provided. The two first are aimed at identifying the adults and juvenile stages of the five genera of the Blaberinae radiation endemic to the Atlantic forest, respectively. The third concerns the identification of the species of the genus Monastria. A map indicating the localities where species were sampled is also provided.

The informative value of museum collections for ecology and conservation: A comparison with target sampling in the Brazilian Atlantic forest

Since two decades the richness and potential of natural history collections (NHC) were rediscovered and emphasized, promoting a revolution in the access on data of species occurrence, and fostering the development of several disciplines. Nevertheless, due to their inherent erratic nature, NHC data are plagued by several biases. Understanding these biases is a major issue, particularly because ecological niche models (ENMs) are based on the assumption that data are not biased. Based on it, a recent body of research have focused on searching adequate methods for dealing with biased data and proposed the use of filters in geographical and environmental space. Although the strength of filtering in environmental space has been shown with virtual species, nothing has yet been tested with a real dataset including field validation. In order to contribute to this task, we explore this issue by comparing a dataset from NHC to a recent targeted sampling of the cockroach genus Monastria Saussure, 1864 in the Brazilian Atlantic forest. We showed that, despite strong similarities, the area modeled with NHC data was much smaller. These differences were due to strong climate biases, which increased model's specificity and reduced sensitivity. By applying two forms of rarefaction in the environmental space, we showed that deleting points at random in the most biased climate class is a powerful way for increasing model's sensitivity, so making predictions more suitable to the reality.

The evolution of sociality in termites from cockroaches: A taxonomic and phylogenetic perspective

Despite multiple studies and advances, sociality still puzzles evolutionary biologists in numerous ways, which might be partly addressed with the advent of sociogenomics. In insects, the majority of sociogenomic studies deal with Hymenoptera, one of the two groups that evolved eusociality with termites. But, to fully grasp the evolution of sociality, studies must obviously not restrict to eusocial lineages. Multiple kinds of social system transitions have been recorded and they all bring complementary insights. For instance, cockroaches, the closest relatives to termites, display a wide range of social interactions and evolved convergently subsocial behaviors (i.e., brood care). In this context, we emphasize the need for natural history, taxonomic, and phylogenetic studies. Natural history studies provide the foundations on which building hypotheses, whereas taxonomy provides the taxa to sample to test these hypotheses, and phylogenetics brings the historical framework necessary to test evolutionary scenarios of sociality evolution.

How the environment shapes animal signals: a test of the acoustic adaptation hypothesis in frogs

Long-distance acoustic signals are widely used in animal communication systems and, in many cases, are essential for reproduction. The acoustic adaptation hypothesis (AAH) implies that acoustic signals should be selected for further transmission and better content integrity under the acoustic constraints of the habitat in which they are produced. In this study, we test predictions derived from the AAH in frogs. Specifically, we focus on the difference between torrent frogs and frogs calling in less noisy habitats. Torrents produce sounds that can mask frog vocalizations and constitute a major acoustic constraint on call evolution. We combine data collected in the field, material from scientific collections and the literature for a total of 79 primarily Asian species, of the families Ranidae, Rhacophoridae, Dicroglossidae and Microhylidae. Using phylogenetic comparative methods and including morphological and environmental potential confounding factors, we investigate putatively adaptive call features in torrent frogs. We use broad habitat categories as well as fine-scale habitat measurements and test their correlation with six call characteristics. We find mixed support for the AAH. Spectral features of torrent frog calls are different from those of frogs calling in other habitats and are related to ambient noise levels, as predicted by the AAH. However, temporal call features do not seem to be shaped by the frogs' calling habitats. Our results underline both the complexity of call evolution and the need to consider multiple factors when investigating this issue.

Ten false ideas about New Caledonia biogeography

The biogeographical paradigm of New Caledonia has recently changed. Although this island is now considered by many as oceanic, its study is still often impeded by some old misconceptions concerning either regional geology or phylogenetic analysis of evolution and biogeography. I discuss ten points that I feel are especially detrimental, to help focus on the real debate and the real questions: (1) its geological history cannot be understood from the basement only; (2) the island submergence was not due simply to sea-level variation; (3) Zealandia/Tasmantis is not a lost continent; (4) short-distance dispersal is not equivalent to permanence on land; (5) long-distance dispersal is not the sole event opposing vicariance, but short-distance dispersal as well; (6) the occurrence of relicts does not prove biota permanence; (7) a major fault system was not observed in New Caledonia; (8) terranes are not rafts; (9) forest climatic refuges do not necessarily equate to centres of endemism or centres of diversity; and (10) New Caledonia is not only a sink but also a source. Study of New Caledonia will need to focus on old and non-relict clades and there is a need to improve the local fossil record.

3-D imaging reveals four extraordinary cases of convergent evolution of acoustic communication in crickets and allies (Insecta)

When the same complex trait is exhibited by closely related species, a single evolutionary origin is frequently invoked. The complex stridulatory apparatus present in the forewings of extant crickets, mole crickets, katydids, and prophalangopsids, is currently interpreted as sharing a single common origin due to their similarity and unique function. An alternative hypothesis of convergent evolution in these ensiferan groups has challenged this common view, but remained controversial because of competing interpretations of wing venation. Here we propose another hypothesis for the widely and long debated homology of ensiferan stridulatory apparatus, performing the first 3D reconstruction of hidden structures at the wing bases. This approach allowed defining the homology of each vein from its very origin rather than after its more distal characteristics, which may be subjected to environmental pressure of selection. The stridulatory apparatus involves different veins in these four singing clades. In light of the most recent phylogenetic evidence, this apparatus developed four times in Ensifera, illustrating extraordinary convergent evolutions between closely related clades, by far exceeding the number of evolutionary steps ever proposed for calling ability in this group.

Outstanding micro-endemism in New Caledonia: More than one out of ten animal species have a very restricted distribution range

New Caledonia is a biodiversity hotspot, with an extremely high number of endemic species with narrow distribution ranges that are at high risk of extinction due to open-cast nickel mining, invasive species and seasonal man-induced fires. Mentions of micro-endemism permeate the literature on the biota of this archipelago. However, so far there has been no research comparing distribution range in different animal groups. The aim of this study is to examine the implication of different sampling effort variables in order to distinguish micro-endemicity from data deficiency, and evaluate the distribution range, frequency, and extent to which micro-endemism is common to several groups of organisms. We compiled a dataset derived from publications in Zoologia Neocaledonica, comprising 1,149 species, of which 86% are endemic to New Caledonia. We found that the sampling effort variables that were best correlated with distribution range were the number of sampling dates and the number of collectors per species. The median value of sampling dates was used to establish a cut-off point for defining adequately sampled species. We showed that, although only 52% of species were sampled adequately enough to determine their distribution range, the number of species with a very narrow distribution range was still high. Among endemics from New Caledonia, 12% (116 species) have ranges ≤5.2km2 and 3.9% (38 species) have ranges between 23 and 100 km2. Surprisingly, a similar trend was observed in non-endemic species: 22% occurred in areas ≤ 5.2 km2, and 8% in areas 23-100 km2, suggesting that environmental dissimilarity may play an important role in the distribution of these species. Micro-endemic species were predominant in 18 out of 20 orders. These results will contribute to a re-assessment of the IUCN red list of species in this archipelago, indicating that at least 116 species are probably critically endangered.

Updating the Phylogenetic Dating of New Caledonian Biodiversity with a Meta-analysis of the Available Evidence

For a long time, New Caledonia was considered a continental island, a fragment of Gondwana harbouring old clades that originated by vicariance and so were thought to be locally ancient. Recent molecular phylogenetic studies dating diversification and geological data indicating important events of submergence during the Paleocene and Eocene (until 37 Ma) brought evidence to dismiss this old hypothesis. In spite of this, some authors still insist on the idea of a local permanence of a Gondwanan biota, justifying this assumption through a complex scenario of survival by hopping to and from nearby and now-vanished islands. Based on a comprehensive review of the literature, we found 40 studies dating regional clades of diverse organisms and we used them to test the hypothesis that New Caledonian and inclusive Pacific island clades are older than 37 Ma. The results of this meta-analysis provide strong evidence for refuting the hypothesis of a Gondwanan refuge with a biota that originated by vicariance. Only a few inclusive Pacific clades (6 out of 40) were older than the oldest existing island. We suggest that these clades could have extinct members either on vanished islands or nearby continents, emphasizing the role of dispersal and extinction in shaping the present-day biota.

Environmental constraints and call evolution in torrent-dwelling frogs

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.

Old Lineage on an Old Island: Pixibinthus, a New Cricket Genus Endemic to New Caledonia Shed Light on Gryllid Diversification in a Hotspot of Biodiversity

Few studies have focused on the early colonization of New Caledonia by insects, after the re-emergence of the main island, 37 Myr ago. Here we investigate the mode and tempo of evolution of a new endemic cricket genus, Pixibinthus, recently discovered in southern New Caledonia. First we formally describe this new monotypic genus found exclusively in the open shrubby vegetation on metalliferous soils, named 'maquis minier', unique to New Caledonia. We then reconstruct a dated molecular phylogeny based on five mitochondrial and four nuclear loci in order to establish relationships of Pixibinthus within Eneopterinae crickets. Pixibinthus is recovered as the sister clade of the endemic genus Agnotecous, mostly rainforest-dwellers. Dating results show that the island colonization by their common ancestor occurred around 34.7 Myr, shortly after New Caledonia re-emergence. Pixibinthus and Agnotecous are then one of the oldest insect lineages documented so far for New Caledonia. This discovery highlights for the first time two clear-cut ecological specializations between sister clades, as Agnotecous is mainly found in rainforests with 19 species, whereas Pixibinthus is found in open habitats with a single documented species. The preference of Pixibinthus for open habitats and of Agnotecous for forest habitats nicely fits an acoustic specialization, either explained by differences in body size or in acoustic properties of their respective habitats. We hypothesize that landscape dynamics, linked to major past climatic events and recent change in fire regimes are possible causes for both present-day low diversity and rarity in genus Pixibinthus. The unique evolutionary history of this old New Caledonian lineage stresses the importance to increase our knowledge on the faunal biodiversity of 'maquis minier', in order to better understand the origin and past dynamics of New Caledonian biota.