The Angiosperm Terrestrial Revolution and the origins of modern biodiversity

Phylogenetic diversity sheds light on the evolution of the unique fern flora of Mount Kinabalu, Borneo

BACKGROUND AND AIMS

Mount Kinabalu is an isolated, geologically young mountain (Pliocene and early Pleistocene) in northern Borneo harbouring a highly diverse flora with a high level of endemism. It is one of the global centres of fern diversity, but how this diversity has evolved has not been studied to date. We assess patterns of evolutionary legacies in the fern flora of Mount Kinabalu, with an emphasis on testing the tropical niche conservatism hypothesis.

METHODS

We used several metrics of phylogenetic structure, including phylogenetic diversity (PD), mean nearest taxon distance (MNTD), mean pairwise distance (MPD), and their respective standardized effect sizes (PDses, MNTDses and MPDses), which represent different depths of evolutionary history, to investigate patterns of evolutionary legacies in the fern flora of Mount Kinabalu.

KEY RESULTS

We found that there was a decrease of PDses with elevation, reflecting a tropical origin of ferns and a gradual evolutionary adaptation to colder environments by fewer successive lineages. However, when separating the evolutionary old non-polypod lineages from the modern polypod radiation, we found a decrease of MNTD with elevation for the former, reflecting an ongoing upslope evolutionary trend, whereas for the modern polypod radiation, the inverse was true. Within the polypods, terrestrial and epiphytic species also showed different patterns, with the former showing a hump-shaped pattern for all phylogenetic diversity metrics, whereas the latter showed a more or less linear decline. Again, this suggests different evolutionary histories for ferns inhabiting the forest floor and canopy, due to the influence of the different habitat conditions. Finally, we found that mean annual temperature had a much stronger effect on phylogenetic diversity metrics than annual precipitation.

CONCLUSIONS

We found that the current fern assemblages on Mount Kinabalu show a strong evolutionary legacy that mirrors that of other mountains, suggesting a global consistency in phylogenetic diversity patterns of ferns along elevational transects, presumably due to a combination of dispersal between mountains and evolutionary convergence.

The radiation of Hymenoptera illuminated by Bayesian inferences from the fossil record

Determining when lineages originated provides fundamental insights into the timing and pace of their diversification, improving our understanding of transformative paleoevents such as the Angiosperm Terrestrial Revolution (ATR)1 and Mid-Mesozoic Parasitoid Revolution (MMPR).2 As the MMPR overlaps with the ATR, improved age estimates help to disentangle the dynamics and temporal succession of these events that shaped modern ecosystems. Hymenoptera (ants, bees, and wasps) played an important role in the MMPR and ATR through their parasitoid and pollinating lineages. Parasitoids impact trophic networks, whereas pollinators interact with flowering plants.3,4 However, our understanding of Hymenoptera diversification remains limited by a lack of fossil-based studies and uncertainties in phylogenetic reconstructions. Combining fossil occurrences and macroevolutionary models, we estimated the origin and diversification of Hymenoptera lineages, considering changes in preservation over time and across taxa.5,6,7 Our results indicate that Hymenoptera diversification is multifaceted and lineage-specific. Sawflies diversified during the Paleozoic and Mesozoic in four episodes (middle Permian, Late Triassic to Middle Jurassic, Early Cretaceous, and the beginning of the Cenozoic) and experienced three extinction episodes (Middle Triassic, Late Jurassic, and mid-Cretaceous). The superfamily Xyeloidea originated during the middle Permian. Apocrita and parasitoid superfamilies emerged during the Early to Middle Triassic, diversified during the Late Jurassic and Early Cretaceous, and declined during the Late Cretaceous. We demonstrate that Hymenoptera experienced successive replacements during the MMPR-likely beginning in the Triassic-and synchronously with changes in floral assemblages of the ATR. We conclude with future directions to refine dating estimates from the fossil record.

Diverse Mesozoic thrips carrying pollen during the gymnosperm-to-angiosperm plant-host ecological shift

Insects are important pollinators, and entomophilous pollination of gymnosperms occurred long before the Cretaceous radiation of angiosperms, but most extant pollination systems involve angiosperms. We studied four thrips of the extinct genus Tethysthrips present in Albian (Early Cretaceous) Spanish amber, one of which carried a patch of gymnosperm Cycadopites pollen grains, some of them attached around the mouthparts, providing direct fossil evidence of pollinivory and pollination. We describe the new species Tethysthrips attenboroughi, which belongs to the extant family Thripidae (suborder Terebrantia). In addition, we studied a Cycadopites pollen load in one specimen belonging to stem group Phlaeothripidae (suborder Tubulifera), from Cenomanian Burmese amber. This illustrates an ancient stage of gymnosperm plant host that most likely favored the later stage involving angiosperms. The absence of extant pollinators of gymnosperms in Thripidae and Phlaeothripidae, and in the terebrantian family Melanthripidae, which contain Cretaceous pollinators of gymnosperms, indicates impoverishment in their gymnosperm relationship.

A global overview of insect-fern interactions and its ecological trends

Historically, ferns have been described as underutilized by insects. However, studies have shown a diversity of insects interacting with ferns, although the evolutionary and ecological drivers of these interactions are still to be untangled. To fill these gaps, we compiled more than 100 yr of global data on insect-fern interactions from the literature comprising 374 fern and 649 insect species. With this database we assessed how fern trophic specialization, phylogenetic relationships and climate have shaped their interactions with insects. Our findings showed that interactions between ferns and insects can be explained by the phylogenetic relations among them. We observed that insect orders part of the Endopterygota clade tend to interact with similar fern species, which might be a result of the inheritance of Endopterygota ancestors probably due to phylogenetic niche conservationism. Under an ecological context, fern specialization increased with temperature, precipitation, and climatic stability. Our results show that climate might be one of the main factors explaining the spatial variation of insect-fern interactions, postulate also supported by the observed phylogenetic clustering of the studied ferns species. Our study highlights the intricate and multifaceted nature of insect-fern interactions, where evolutionary history and ecological factors converge to shape these relationships.

On the uniqueness of fern-insect interactions

This article is a Commentary on Porto et al. (2025), 246: 747–757.

Major shifts in embryo size occurred early in the evolutionary history of angiosperms

Seeds are the main dispersal and propagation units of angiosperms. Examining the relative allocation of seed reserves by quantifying the relative embryo size (ES) at dispersal (i.e. size of the embryo relative to the seed) across angiosperms, sets the basis to track the evolutionary history of this key reproductive trait related to germination timing and offspring survival. We used a robust, dated phylogeny and sampling of ES for selected species across most angiosperm families to model the macroevolution of ES. Data on ES were collated from living specimens and primary literature. Early angiosperms typically had a low ES, which is still reflected in contemporary magnoliids and ANA-grade species. The analysis of major evolutionary shifts in ES throughout angiosperm phylogeny revealed that these shifts were predominantly associated with the formation of the main angiosperm lineages. The tempo and mode of ES evolution were not constant over angiosperm history, paralleling major paleo-events. This study provides crucial new insights in seed trait evolution, which contribute to understanding the diversification of reproductive strategies in angiosperms.

The Role of Plant Evolutionary History in Shaping the Variation in Specific Leaf Area Across China

Specific leaf area (SLA, leaf area per unit leaf dry mass) occupies a central position in both community assembly and ecosystem functioning. Although SLA has significant phylogenetic signals, how and to what extent the evolutionary history influences the variation in SLA remain poorly understood. In this study, based on a dataset containing 1264 plant species belonging to 549 genera and 141 families in gymnosperms, monocots, and eudicots across China, we analyzed the influences of climatic conditions and soil properties on SLA, calculated the phylogenetic signals of SLA, and quantified the relative contributions of evolutionary history (represented by interspecific relatedness and intraspecific variation) to the variation in SLA. The results showed that the interspecific relatedness accounts for 50.46% of the total variance in SLA, followed by the intraspecific variation (36.12%), climatic conditions (30.68%), and soil properties (24.74%). Along the phylogenetic tree, the split between angiosperms and gymnosperms had the largest contribution to the variation in SLA. Other detailed splits (e.g., the split between monocots and eudicots, the splits within Rosidae, and etc.) had significant but much smaller contributions. The relationship between SLA and environmental variables (climatic conditions and soil properties) was different between angiosperms and gymnosperms, with the climatic conditions having larger influences on SLA than the soil properties, implying interactive effects between environment and evolutionary history on SLA. Within the woody angiosperms, deciduous and evergreen species exhibited differential responses of SLA to climatic and soil factors, suggesting a non-negligible role of leaf longevity in explaining the variation in SLA. Our results highlighted a much more important role of evolutionary history in the variation in SLA than previous studies. Neglecting such a great contribution could lead to biased conclusions if the evolutionary rate does not keep pace with the rapidly changing environments in the future.

Evolution of the JULGI-SMXL4/5 module for phloem development in angiosperms

Bifacial cambium, which produces xylem and phloem, and monopodial architecture, characterized by apical dominance and lateral branching from axillary buds, are key developmental features of seed plants, consisting of angiosperms and gymnosperms. These allow seed plants to adapt to diverse environments by optimizing resource allocation and structural integrity. In seed plants, SUPPRESSOR OF MAX2-LIKE (SMXL) family members function in phloem development and strigolactone-induced inhibition of axillary bud outgrowth. Although strigolactone signaling regulates most SMXL family members, the only known regulator of SMXL4 and SMXL5 is the RNA-binding protein JULGI. We demonstrate that in angiosperms, by directly regulating SMXL4/5 expression, JULGI uncouples SMXL4/5 activity from strigolactone signaling. JULGI and ancestral SMXLs from seedless vascular plants or SMXL4/5 from seed plants are coexpressed in the phloem tissues of vascular plants, from lycophytes to angiosperms. Core angiosperm SMXL4/5 mRNAs contain a G-rich element in the 5' untranslated region (UTR) that serves as a target sequence for JULGI to negatively regulate SMXL4/5 expression. Heterologous expression of JULGIs from various angiosperms rescued the Arabidopsis jul1 jul2 mutant. Expressing SMXL4/5s from seed plants and ancestral SMXLs rescued Arabidopsis smxl4 smxl5. Angiosperm SMXL4/5s lack an RGKT motif for proteasomal degradation. Indeed, treatment with the synthetic strigolactone analog rac-GR24 induced proteasomal degradation of SMXL from ferns and SMXL5a from gymnosperms, but not SMXL4/5 from angiosperms. These findings suggest that in ancestral angiosperms, the 5' UTR of SMXL4/5 gained G-rich elements, creating a regulatory module with JULGI that allows the phloem development pathway to act independently of strigolactone signaling.

Diversification and extinction of Hemiptera in deep time

Untangling the patterns and drivers behind the diversification and extinction of highly diversified lineages remains a challenge in evolutionary biology. While insect diversification has been widely studied through the "Big Four" insect orders (Coleoptera, Hymenoptera, Lepidoptera and Diptera), the fifth most diverse order, Hemiptera, has often been overlooked. Hemiptera exhibit a rich fossil record and are highly diverse in present-day ecosystems, with many lineages closely associated to their host plants, making them a crucial group for studying how past ecological shifts-such as mass extinctions and floral turnovers-have influenced insect diversification. This study leverages birth-death models in a Bayesian framework and the fossil record of Hemiptera to estimate their past diversity dynamics. Our results reveal that global changes in flora over time significantly shaped the evolutionary trajectories of Hemiptera. Two major faunal turnovers particularly influenced Hemiptera diversification: (i) the aftermath of the Permo-Triassic mass extinction and (ii) the Angiosperm Terrestrial Revolution. Our analyses suggest that diversification of Hemiptera clades was driven by floristic shifts combined with competitive pressures from overlapping ecological niches. Leveraging the extensive fossil record of Hemiptera allowed us to refine our understanding of diversification patterns across major hemipteran lineages.

Molecular advances in research and applications of male sterility systems in tomato

Tomato, belonging to the nightshade family, is globally considered as a model system for classical and molecular genetics, genomics, and reproductive developmental studies. In the current scenario of climate change, hybrid development is among the crucial elements in the genetic improvement of crop plants. The phenomenon of male sterility is a viable approach for ensuring hybrid seed purity and reducing the cost of hybrid seed production. This review aims to shed light on the use of neoteric genomics and genome editing tools in understanding the genetics and molecular regulation of male sterility in tomato. Plant male gametophyte development is highly susceptible to environmental stress. Abnormalities at any stage of male reproductive development, such as premature or delayed tapetal cell degradation triggered by oxidative stress and programmed cell death (PCD) leads to male sterility in tomato. In tomato, more than 55 sporogenous, structural, and functional male sterile mutants, which are mainly under the control of recessive nuclear genes, have been reported. Recently, the role of open reading frames (ORFs) in governing cytoplasmic male sterility in tomato has also been documented. This review highlights the genetic and genomic progress in the investigation of underlying molecular pathways and practical application of potential male sterile mutants in tomato breeding. The applications and future prospects of genome engineering with CRISPR/Cas9 and mitoTALEN in the generation of novel male sterile systems to expedite tomato breeding is discussed.

New ovulate cupule further informs the relationships among early seed plants and their adaptation to wind pollination

The earliest seed plants occurred in the Late Devonian (Famennian). However, why and how they rapidly diversified remain long-standing mysteries. We investigated the early evolution of seed plants based on a new ovule and evaluated wind pollination performance of the earliest cupulate ovules by using computational fluid dynamics simulations. Zaijunia biloba gen. et sp. nov. is described from the Upper Devonian (Famennian) of South China and shows canonical hydrasperman-type ovules with lobed integuments and a complex nucellar apex. Zaijunia bears ovules in pairs, each ovule within a lateral bilobed cupule. We propose that duplication of the bi-ovulate fertile unit of Zaijunia could produce more complex derivative cupulate ovules, as an evolutionary pathway leading to the early diversification of seeds. We performed computational fluid dynamics simulations of Zaijunia and two other early seed plants (i.e. Pseudosporogonites and Elkinsia), demonstrating that their fertile units improve airborne (pre)pollen capture efficiency. This study sheds additional light on the evolution of cupulate ovules and their potential adaptations to anemophily, as one of the factors driving the earliest radiation of seed plants.

The atypical proteome of mitochondria from mature pollen grains

To propagate their genetic material, flowering plants rely on the production of large amounts of pollen grains that are capable of germinating on a compatible stigma. Pollen germination and pollen tube growth are thought to be extremely energy-demanding processes. This raises the question of whether mitochondria from pollen grains are specifically tuned to support this developmental process. To address this question, we isolated mitochondria from both mature pollen and floral buds using the isolation of mitochondria tagged in specific cell-type (IMTACT) strategy and examined their respective proteomes. Strikingly, mitochondria from mature pollen grains have lost many proteins required for genome maintenance, gene expression, and translation. Conversely, a significant accumulation of proteins associated with the tricarboxylic acid (TCA) cycle, the electron transport chain (ETC), and Ca2+ homeostasis was observed. This supports the current model in which pollen requires large quantities of ATP for tube growth but also identifies an unexpected depletion of the gene expression machinery, aligned with the fact that the mitochondrial genome is actively degraded during pollen maturation. Altogether, our results uncover that mitochondria from mature pollen grains are strategically prepared for action by increasing their respiratory capacity and dismantling their gene expression machinery, which raises new questions about the assembly of respiratory complexes in pollen mitochondria, as they rely on the integration of proteins coded by the nuclear and mitochondrial genomes. In addition, the approach described here opens a new range of possibilities for studying mitochondria during pollen development and in pollen-specific mitochondrial events.

Ecological change and conflict reduction led to a social circulatory system in ants

Behavioral innovations can be ecologically transformative for lineages that perform them and for their associated communities. Many ecologically dominant, superorganismal, and speciose ant lineages use mouth-to-mouth social regurgitation behavior - stomodeal trophallaxis - to share exogenous and endogenous materials within colonies. This behavior is less common in other species-poor, less cooperative ant lineages. How and why trophallaxis evolved and fixed in only some ant clades remains unclear, and whether this trait could be indicative of superorganismality has yet to be established. Here we show that trophallaxis evolved in two main events, in non-doryline formicoids around 130 Ma and in some ponerines around 90 Ma, lineages that today encompass 86% of all ant species. We found that trophallaxis evolved in lineages that began drinking sugary liquids and that had reduced intra-colonial conflict by constraining worker reproductive potential. Evolution of trophallaxis increased net diversification. Causal models indicate that trophallaxis required low reproductive conflict and contributed to the large colony sizes of the ants that use it. This suggests that the evolution of social regurgitation was enabled by both social conflict reduction and opportunistic inclusion of nectar and honeydew in the ant diet during the shifts in terrestrial ecosystems toward flowering plants.

Phylogenomics of angiosperms based on mitochondrial genes: insights into deep node relationships

BACKGROUND

Angiosperms are the largest plant group and play an essential role in the biosphere. Phylogenetic relationships of many families and orders remain contentious, and, in an attempt to address these, we performed the most extensive sampling of mitochondrial genes to date.

RESULTS

We reconstructed a seed plant phylogenetic framework based on 41 mitochondrial protein-coding sequences (mtCDSs), representing 335 families and 63 orders with 481 angiosperm species. The results for major clades of angiosperms produced moderate to strong support (> 70% bootstrap) for more than 80% of nodes and strong support for most orders. Eight major nodes were supported, including the three paraphyletic ANA orders (Amborellales, Nymphaeales, and Austrobaileyales) and five major core-angiosperm clades. Chloranthales and Ceratophyllales are sister to the eudicots, whereas the monocots are sister to the magnoliids. Although well-supported, relationships within the asterids and rosids were in some cases unresolved or weakly supported, due to the low levels of variability detected in these genes.

CONCLUSIONS

Our results indicated that mitochondrial genomic data were effective at resolving deep node relationships of angiosperm phylogeny and thus represent an important resource for phylogenetics and evolutionary studies of angiosperm.

Symbiosis and horizontal gene transfer promote herbivory in the megadiverse leaf beetles

Beetles that feed on the nutritionally depauperate and recalcitrant tissues provided by the leaves, stems, and roots of living plants comprise one-quarter of herbivorous insect species. Among the key adaptations for herbivory are plant cell wall-degrading enzymes (PCWDEs) that break down the fastidious polymers in the cell wall and grant access to the nutritious cell content. While largely absent from the non-herbivorous ancestors of beetles, such PCWDEs were occasionally acquired via horizontal gene transfer (HGT) or by the uptake of digestive symbionts. However, the macroevolutionary dynamics of PCWDEs and their impact on evolutionary transitions in herbivorous insects remained poorly understood. Through genomic and transcriptomic analyses of 74 leaf beetle species and 50 symbionts, we show that multiple independent events of microbe-to-beetle HGT and specialized symbioses drove convergent evolutionary innovations in approximately 21,000 and 13,500 leaf beetle species, respectively. Enzymatic assays indicate that these events significantly expanded the beetles' digestive repertoires and thereby contributed to their adaptation and diversification. Our results exemplify how recurring HGT and symbiont acquisition catalyzed digestive and nutritional adaptations to herbivory and thereby contributed to the evolutionary success of a megadiverse insect taxon.

[The role of volatile organic compounds in plant-insect communication]

Insects and flowering plants are the most abundant and diverse multicellular organisms on Earth, accounting for 75% of known species. Their evolution has been largely interdependent since the so-called Angiosperm Terrestrial Revolution (100-50 Mya), when the explosion of plant diversity stimulated the evolution of pollinating and herbivorous insects. Plant-insect interactions rely heavily on chemical communication via volatile organic compounds (VOCs). These molecules are synthesised by the secondary metabolism of plants through various pathways and include terpenes, benzenoids and aliphatic compounds. As of today, more than 1,700 of these VOCs have notably been identified in flowers. Plants use these molecules to attract pollinators or repel herbivorous insects. VOCs also act as chemical signals for insects, helping them to find food or egg-laying sites. Chemical communication has thus played an important role in the evolutionary history of insects and flowering plants. Tritrophic interactions are a fascinating example of VOC-driven communication. When plants are attacked by herbivores, they emit herbivore-induced volatiles, such as green leaf volatiles and specific terpenes. These signals attract predators or parasitoids of the herbivores, acting as a chemical distress call. For example, parasitoid wasps can identify plants that have been attacked by their host herbivores, even in the absence of the herbivores themselves, thanks to the plant's odour profile. But herbivore-induced volatiles also affect the herbivores themselves. Female moths, for example, use these olfactory cues to avoid laying eggs on plants that have already been attacked. Insects detect VOCs using highly sensitive odorant receptors on their antennae. Herbivorous insects, such as the model moth species S. littoralis, have receptors specific for floral VOCs and herbivore-induced volatiles. Current research aims to understand how the evolution of these receptors has contributed to the adaptation of insects to plant volatiles. In moths, receptors for benzenoids appear to be more ancient and conserved, whereas receptors for terpenes and aliphatic molecules show more recent diversification in response to plant evolution. Research into plant-insect communication also opens up avenues for sustainable agriculture, as VOCs can be used to attract natural pest predators or deter herbivores, reducing the need for chemical pesticides.

Cursorial ecomorphology and temporal patterns in theropod dinosaur evolution during the mid-Cretaceous

Coelurosauria, including modern birds, represents a successful group of theropod dinosaurs that established a high taxonomic diversity and significant morphological modifications. In the evolutionary history of this group, a specialized foot morphology, the arctometatarsus, evolved independently in several lineages and has been considered an adaptation for cursoriality. While its functional significance has been extensively studied, the temporal pattern of this parallel evolution, as well as its origin and influencing factors, remains largely unresolved. Here, we show the temporal evolution of cursorial traits, including the arctometatarsus and hind limb proportions. Our study reveals that the proportional elongation of distal hind limb segments preceded the evolution of the arctometatarsus in ornithomimosaurs and oviraptorosaurs. In contrast, in tyrannosauroids, alvarezsaurs and troodontids, the proportional elongation of the tibia and metatarsals occurred in parallel with the acquisition of the arctometatarsus. The evolutionary history of the arctometatarsus further highlights the presence of a phylogenetic constraint outside Coelurosauria, as this foot specialization is restricted to members of this group. Finally, our date estimation, based on compiled evolutionary patterns, demonstrates that these cursorial traits emerged during the mid-Cretaceous (93-120 Ma), suggesting selection on theropod locomotor performance throughout this interval.

Untangling poikilohydry and desiccation tolerance: evolutionary and macroecological drivers in ferns

BACKGROUND AND AIMS

Poikilohydry describes the inability of plants to internally regulate their water content (hydroregulation), whereas desiccation tolerance (DT) refers to the ability to restore normal metabolic functions upon rehydration. The failure to clearly separate these two adaptations has impeded a comprehensive understanding of their unique evolutionary and ecological drivers. Unlike bryophytes and angiosperms, these adaptations in ferns are sometimes uncorrelated, offering a unique opportunity to navigate their intricate interplay.

METHODS

We classified ferns into two syndromes: the Hymenophyllum-type (H-type), encompassing species with filmy leaves lacking stomata that experience extreme poikilohydry and varying degrees of DT, and the Pleopeltis-type (P-type), consisting of resurrection plants with variable hydroregulation but high DT.

KEY RESULTS

The H-type evolved during globally cool Icehouse periods, as an adaptation to low light levels in damp, shady habitats, and currently prevails in wet environments. Conversely, the P-type evolved predominantly under Greenhouse periods as an adaptation to periodic water shortage, with most extant species thriving in warm, seasonally dry habitats.

CONCLUSIONS

Out study underscores the fundamental differences between poikilohydry and DT, emphasizing the imperative to meticulously differentiate and qualify the strength of each strategy as well as their interactions, as a basis for understanding the genetic and evolutionary background of these ecologically crucial adaptations.

A new species of Elodophthalmus from Lower Cretaceous Lebanese amber unravels the systematic placement of Elodophthalmidae and reconciling phylogenetic conflicts within Tenebrionoidea

Elodophthalmidae, represented by the sole genus Elodophthalmus Kirejtshuk & Azar, is an extinct beetle family described from Lower Cretaceous Lebanese amber. Elodophthalmidae has been hypothesized to share close affinities with the extant superfamily Scirtoidea, but their exact systematic position remains elusive. Here, we describe a new species of Elodophthalmus, Elodophthalmus maksoudae sp. nov., based on a well-preserved fossil from Early Cretaceous amber collected in Hammana/Mdeyrij, Central Lebanon, the same locality as other congeneric species. Using improved imaging technologies, we reveal detailed morphological characters of the fossil, providing critical evidence for a more robust systematic placement of Elodophthalmus. Our findings present compelling evidence supporting the placement of Elodophthalmidae within the superfamily Tenebrionoidea. Furthermore, we highlight that conflicts in the interfamilial relationships within Tenebrionoidea across various datasets can, at least partially, be mitigated by adopting the site-heterogeneous CAT-GTR+G model. We suggest that the traditional reliance on site-homogeneous models in Sanger sequencing-based studies may fail to capture the complexities of nucleotide substitution patterns. With the increasing recognition of the importance of modeling among-site compositional heterogeneity, our study points to the necessity for more rigorous model testing in the phylogenetic studies of ancient lineages such as Tenebrionoidea.

Anthophilous beetles ubiquitously inhabit night-blooming cacti but exhibit distinct responses to the spatial distribution of flowers

Night-blooming cacti, primarily pollinated by bats and hawkmoths, also attract beetles seeking food and safe shelter for mating and brooding their offspring. The influence of flower density on beetle visitation rates remains unclear, with responses varying by species and environmental factors. In the Caatinga Seasonally Dry Tropical Forest, we studied the flower occupancy distribution of two beetle species, Cyclocephala paraguayensis and Nitops aff. pilosocerei, in Pilosocereus pachycladus cacti. Our findings indicate that both beetle species act as commensals with minimal impact on effective pollination. They forage for nectar and pollen without causing damage to pistils or ovaries. N. aff. pilosocerei was more abundant than C. paraguayensis, and their distributions significantly differed, with N. aff. pilosocerei displaying a more uniform spread. Instances of both species occupying the same flower were more frequent than exclusive occupation. Nitops aff. pilosocerei abundance exhibited spatial autocorrelation. Flower height and beetle species influenced the total number of beetles within flowers. Future studies should explore the impact of cactus flower distribution on beetle abundance with other species, conduct selective pollination experiments to determine their role as pollinators, and investigate how flower-beetle interaction systems are affected by flower and individual distribution in processes like florivory and pollination.

Uncovering the mechanical secrets of the squirting cucumber

Rapid movement is rare in the plant kingdom, but a prerequisite for ballistic seed dispersal. A particularly dramatic example of rapid motion in plants is the squirting cucumber (Ecballium elaterium) which launches its seeds explosively via a high-pressure jet. Despite intriguing scientists for centuries, the exact mechanism of seed dispersal and its effect on subsequent generations remain poorly understood. Here, through a combination of experimentation, high-speed videography, quantitative image analysis, and mathematical modeling, we develop a full mechanical description of the process. We quantify the turgor pressure driving ballistic ejection, and uncover key mechanical interactions between the fruit and stem both prior to and during seed ejection, including the unique feature that fluid is redistributed from fruit to stem prior to ejection, a developmental event that goes against the paradigm of rapid seed ejection but which is of key importance in successful dispersal for Ecballium. Combining modeling elements, we quantify and simulate the ballistic trajectories of seeds, which are dispersed over distances greater than 2,000 times their length. We demonstrate how together these mechanical features contribute to a nearly uniform distribution of seeds away from the parent plant. Parametric variation of key developmental events in the modeling framework indicates how a suite of adaptive features in combination drives the spatial distribution of offspring over consecutive generations, and suggests that ballistic seed dispersal has a stabilizing effect on population dynamics by reducing intraspecific competition.

Deciphering the evolution and biogeography of ant-ferns Lecanopteris s.s

Southeast Asia is a biodiversity hotspot characterized by a complex paleogeography, and its Polypodiopsida flora is particularly diverse. While hybridization is recognized as common in ferns, further research is needed to investigate the relationship between hybridization events and fern diversity. Lecanopteris s.s., an ant-associated fern, has been subject to debate regarding species delimitations primarily due to limited DNA markers and species sampling. Our study integrates 22 newly generated plastomes, 22 transcriptomes, and flow cytometry of all native species along with two cultivated hybrids. Our objective is to elucidate the reticulate evolutionary history within Lecanopteris s.s. through the integration of phylobiogeographic reconstruction, gene flow inference, and genome size estimation. Key findings of our study include: (1) An enlarged plastome size (178-187 Kb) in Lecanopteris s.s., attributed to extreme expansion of the Inverted Repeat (IR) regions; (2) The traditional 'pumila' and 'crustacea' groups are paraphyletic; (3) Significant cytonuclear discordance attributed to gene flow; (4) Natural hybridization and introgression in the 'pumila' and 'darnaedii' groups; (5) L. luzonensis is the maternal parent of L. 'Yellow Tip', with L. pumila suggested as a possible paternal parent; (6) L. 'Tatsuta' is a hybrid between L. luzonensis and L. crustacea; (7) Lecanopteris s.s. first diverged during the Neogene and then during the middle Miocene climatic optimum in the Indochina and Sundaic regions. In conclusion, the biogeographic history and speciation of Lecanopteris have been profoundly shaped by past climate changes and geodynamics of Southeast Asia. Dispersals, hybridization and introgression between species act as pivotal factors in the evolutionary trajectory of Lecanopteris s.s.. This research provides a robust framework for further exploration and understanding of the complex dynamics driving the diversification and distribution patterns within Polypodiaceae subfamily Microsoroideae.

Phosphoproteomic analysis of distylous Turnera subulata identifies pathways related to endoreduplication that correlate with reciprocal herkogamy

PREMISE

A multi-omic approach was used to explore proteins and networks hypothetically important for establishing filament dimorphisms in heterostylous Turnera subulata (Sm.) as an exploratory method to identify genes for future empirical research.

METHODS

Mass spectrometry (MS) was used to identify differentially expressed proteins and differentially phosphorylated peptides in the developing filaments between the L- and S-morphs. RNAseq was used to generate a co-expression network of the developing filaments, MS data were mapped to the co-expression network to identify hypothetical relationships between the S-gene responsible for filament dimorphisms and differentially expressed proteins.

RESULTS

Mapping all MS identified proteins to a co-expression network of the S-morph's developing filaments identified several clusters containing SPH1 and other differentially expressed or phosphorylated proteins. Co-expression analysis clustered CDKG2, a protein that induces endoreduplication, and SPH1-suggesting a shared biological function. MS analysis suggests that the protein is present and phosphorylated only in the S-morph, and thus active only in the S-morph. A series of CDKG2 regulators, including ATM1, and cell cycle regulators also correlated with the presence of reciprocal herkogamy, supporting our interest in the protein.

CONCLUSIONS

This work has built a foundation for future empirical work, specifically supporting the role of CDKG2 and ATM1 in promoting filament elongation in response to SPH1 perception.

Cranial anatomy of Acynodon adriaticus and extreme durophagous adaptations in Eusuchia (Reptilia: Crocodylomorpha)

Acynodon adriaticus, a small eusuchian from the Late Cretaceous of Italy, is known for its well-preserved cranial and postcranial material. Despite its excellent preservation, many details remain hidden due to the physical overlap between the elements and matrix obliteration. We used Micro-CT scans to reveal previously overlooked anatomical features and describe in detail the cranial and dental anatomy of this taxon, shedding new light on its palaeoecology. The holotypic specimen, SC 57248, represents a mature individual exhibiting signs of hyperossification, developed ornamentation, and various pathologies, including jaw arthritis and a possible dental anomaly. Acynodon adriaticus exhibits significant durophagous adaptations, including a robust, brevirostrine skull optimized for powerful biting and stress-load capacity. Its specialized dentition, lacking caniniform teeth, features anterior chisel-like teeth and hypertrophic posterior molariforms with thick enamel, indicative of a diet specializing in hard-shelled prey. The dentition pattern, accelerated molariform replacement rate, and reduced orbit size suggest adaptations for durophagous foraging in turbid, densely vegetated aquatic environments. The paleoecological context during the Late Cretaceous, characterized by increased freshwater habitats and high invertebrate diversity, likely facilitated the evolution of such specialized traits in A. adriaticus. This small crocodylomorph likely foraged slowly in shallow, benthic environments, using its powerful bite to process mollusks and large arthropods. The study of A. adriaticus, along with comparisons with other crocodylomorphs and ecomorphologically similar taxa like Iharkutosuchus makadii and Gnatusuchus pebasensis, provides a valuable morphofunctional model for understanding the evolutionary pathways of extinct crocodylians to durophagy.

Comparative analysis of amino acid sequence level in plant GATA transcription factors

Transcription factors (TFs) are essential regulators of gene expression, influencing numerous biological processes such as development, growth, and cellular responses in plants. Among these, GATA TFs are distinguished by their highly conserved DNA-binding domain, characterized by a class IV zinc finger motif (CX2CX18-20CX2C). This study investigates the amino acid sequence patterns of 5,335 GATA TFs across 165 plant species sourced from the PlantTFDB database ( http://planttfdb.gao-lab.org/ ), encompassing diverse taxonomic groups. Through comparative sequence analysis, I identify conserved domains and structural features that enhance the understanding functional roles, evolutionary conservation, and lineage-specific adaptations of GATA TFs. These findings provide valuable insights into the diversification and functional specialization of GATA TFs, with implications for improving stress tolerance and adaptability in crops. This study contributes to the broader knowledge of transcriptional regulation in plant biology.

Bona Fide Plant Steroid Receptors are Innovated in Seed Plants and Angiosperms through Successive Whole-Genome Duplication Events

Whole-genome duplication (WGD) events are widespread in plants and animals, thus their long-term evolutionary contribution has long been speculated, yet a specific contribution is difficult to verify. Here, we show that ɛ-WGD and ζ-WGD contribute to the origin and evolution of bona fide brassinosteroid (BR) signaling through the innovation of active BR biosynthetic enzymes and active BR receptors from their respective ancestors. We found that BR receptors BRI1 (BR INSENSITIVE 1) and BRL1/3 (BRI1-LIKES 1/3) derived by ɛ-WGD and ζ-WGD, which occurred in the common ancestor of angiosperms and seed plants, respectively, while orphan BR receptor BRL2 first appeared in stomatophytes. Additionally, CYP85A enzymes synthesizing the bioactive BRs derived from a common ancestor of seed plants, while its sister enzymes CYP90 synthesizing BR precursors presented in all land plants, implying possible ligand-receptor coevolution. Consistently, the island domains (IDs) responsible for BR perception in BR receptors were most divergent among different receptor branches, supporting ligand-driven evolution. As a result, BRI1 was the most diversified BR receptor in angiosperms. Importantly, relative to the BR biosynthetic DET2 gene presented in all land plants, BRL2, BRL1/3 and BRI1 had high expression in vascular plants ferns, gymnosperms and angiosperms, respectively. Notably, BRI1 is the most diversified BR receptor with the most abundant expression in angiosperms, suggesting potential positive selection. Therefore, WGDs initiate a neofunctionalization process diverged by ligand-perception and transcriptional expression, which might optimize both BR biosynthetic enzymes and BR receptors, likely contributing to the evolution of land plants, especially seed plants and angiosperms.

The seed morphospace, a new contribution towards the multidimensional study of angiosperm sexual reproductive biology

BACKGROUND

The evolutionary success of flowering plants is associated with the vast diversity of their reproductive structures. Despite recent progress in understanding angiosperm-wide trends in floral structure and evolution, a synthetic view of the diversity in seed form and function across angiosperms is lacking.

SCOPE

Here we present a roadmap to synthesize the diversity of seed forms in extant angiosperms, relying on the morphospace concept, i.e. a mathematical representation which relates multiple traits and describes the realized morphologies. We provide recommendations on how to broaden the range of measurable traits beyond mass, by using key morphological traits representative of the embryo, endosperm and seed coat but also fruit attributes (e.g. dehiscence, fleshiness). These key traits were used to construct and analyse a morphospace to detect evolutionary trends and gain insight into how morphological traits relate to seed functions. Finally, we outline challenges and future research directions, combining the morphospace with macroevolutionary comparative methods to underline the drivers that gave rise to the diversity of observed seed forms.

CONCLUSIONS

We conclude that this multidimensional approach has the potential, although still untapped, to improve our understanding of covariation among reproductive traits, and further elucidate angiosperm reproductive biology as a whole.

Where did they come from, where did they go? Niche conservatism in woody and herbaceous plants and implications for plant-based paleoclimatic reconstructions

PREMISE

The ecological conditions that constrain plants to an environmental niche are assumed to be constant through time. While the fossil record has been used previously to test for niche conservatism of woody flowering plants, additional studies are needed in other plant groups especially since they can provide insight with paleoclimatic reconstructions, high biodiversity in modern terrestrial ecosystems, and significant contributions to agriculture.

METHODS

We tested climatic niche conservatism across time by characterizing the climatic niches of living herbaceous ginger plants (Zingiberaceae) and woody dawn redwood (Metasequoia) against paleoniches reconstructed based on fossil distribution data and paleoclimatic models.

RESULTS

Despite few fossil Zingiberaceae occurrences in the latitudinal tropics, unlike living Zingiberaceae, extinct Zingiberaceae likely experienced paratropical conditions in the higher latitudes, especially in the Cretaceous and Paleogene. The living and fossil distributions of Metasequoia largely remain in the upper latitudes of the northern hemisphere. The Zingiberaceae shifted from an initial subtropical climatic paleoniche in the Cretaceous, toward a temperate regime in the late Cenozoic; Metasequoia occupied a more consistent climatic niche over the same time intervals.

CONCLUSIONS

Because of the inconsistent climatic niches of Zingiberaceae over geologic time, we are less confident of using them for taxonomic-based paleoclimatic reconstruction methods like nearest living relative, which assume a consistent climatic niche between extant and extinct relatives; we argue that the consistent climatic niche of Metasequoia is more appropriate for these reconstructions. Niche conservatism cannot be assumed between extant and extinct plants and should be tested further in groups used for paleoclimatic reconstructions.

The macroecology of Mesozoic dinosaurs

Dinosaurs thrived for over 160 million years in Mesozoic ecosystems, displaying diverse ecological and evolutionary adaptations. Their ecology was shaped by large-scale climatic and biogeographic changes, calling for a 'deep-time' macroecological investigation. These factors include temperature fluctuations and the break up of Pangaea, influencing species richness, ecological diversity and biogeographic history. Recent improvements in the dinosaur fossil record have enabled large-scale studies of their responses to tectonic, geographic and climatic shifts. Trends in species diversity, body size and reproductive traits can now be analysed using quantitative approaches like phylogenetic comparative methods, machine learning and Bayesian inference. These patterns sometimes align with, but also deviate from, first-order macroecological rules (e.g. species-area relationship, latitudinal biodiversity gradient, Bergmann's rule). Accurate reconstructions of palaeobiodiversity and niche partitioning require ongoing taxonomic revisions and detailed anatomical descriptions. Interdisciplinary research combining sedimentology, geochemistry and palaeoclimatology helps uncover the environmental conditions driving dinosaur adaptations. Fieldwork in under-sampled regions, particularly at latitudinal extremes, is crucial for understanding the spatial heterogeneity of dinosaur ecosystems across the planet. Open science initiatives and online databases play a key role in advancing this field, enriching our understanding of deep-time ecological processes, and offering new insights into dinosaur macroecology and its broader implications.

Foraging by predatory ants: A review

In this review, we show that predatory ants have a wide range of foraging behavior, something expected given their phylogenetic distance and the great variation in their colony size, life histories, and nesting habitats as well as prey diversity. Most ants are central-place foragers that detect prey using vision and olfaction. Ground-dwelling species can forage solitarily, the ancestral form, but generally recruit nestmates to retrieve large prey or a group of prey. Typically, ants are omnivorous, but some species are strict predators preying on detritivorous invertebrates or arthropod eggs, while those specialized on termites or other ants often have scouts that localize their target and then trigger a raid. They can use compounds that ease this task, including chemical insignificance, mimicry, and venoms triggering submissive behavior. Army ants include 8 Dorylinae and some species from other subfamilies, all having wingless queens and forming raids. Dorylinae from the Old World migrate irregularly to new nesting sites. The foraging of most New World species that prey on the brood of other ants is regulated by their biological cycle that alternates between a "nomadic phase" when the colony relocates between different places and a "stationary phase" when the colony stays in a bivouac constituting a central place. Among arboreal ants, dominant species forage in groups, detecting prey visually, but can use vibrations, particularly when associated with myrmecophytes. Some species of the genera Allomerus and Azteca use fungi to build a gallery-shaped trap with small holes under which they hide to ambush prey.

The evolution of ectomycorrhizal symbiosis and host-plant switches are the main drivers for diversification of Amanitaceae (Agaricales, Basidiomycota)

BACKGROUND

Evolutionary radiation is widely recognized as a mode of species diversification, but the drivers of the rapid diversification of fungi remain largely unknown. Here, we used Amanitaceae, one of the most diverse families of macro-fungi, to investigate the mechanism underlying its diversification.

RESULTS

The ancestral state of the nutritional modes was assessed based on phylogenies obtained from fragments of 36 single-copy genes and stable isotope analyses of carbon and nitrogen. Moreover, a number of time-, trait-, and paleotemperature-dependent models were employed to investigate if the acquisition of ectomycorrhizal (ECM) symbiosis and climate changes promoted the diversification of Amanitaceae. The results indicate that the evolution of ECM symbiosis has a single evolutionary origin in Amanitaceae. The earliest increase in diversification coincided with the acquisition of the ECM symbiosis with angiosperms in the middle Cretaceous. The recent explosive diversification was primarily triggered by the host-plant switches from angiosperms to the mixed forests dominated by Fagaceae, Salicaceae, and Pinaceae or to Pinaceae.

CONCLUSIONS

Our study provides a good example of integrating phylogeny, nutritional mode evolution, and ecological analyses for deciphering the mechanisms underlying fungal evolutionary diversification. This study also provides new insights into how the transition to ECM symbiosis has driven the diversification of fungi.

[Evolution of plant mating systems in the face of global change]

Beyond species extinction, it is likely that global change modifies selection regimes in natural populations. Whereas the classical Darwinian paradigm considers evolution as a slow process, it is now accepted that populations can evolve rapidly, in a few dozen generations. Plant-pollinator relationship is a central relationship in terrestrial ecosystems and the current pollinator decline can potentially disrupt this relationship. In this paper, we explore the possibility that reproductive systems in plants evolve in the face of pollinator decline. Using the case of a recent resurrection ecology study in Viola arvensis, the field pansy, we show that the evolution of a self-fertilization syndrome, and thus the breakdown of the plant-pollinator interaction, is in progress. Beyond the species itself, the evolution of reproductive regimes in plants involves relationships between species (pollinators and higher trophic levels). Thus, this example illustrates that global change is likely to affect biodiversity at different scales: from populations (Darwinian evolution) to ecosystem functions (relationships between species). This study shows that evolutionary processes modify the functioning of ecological systems and, where applicable, the related ecosystem services.

The meaning of mass extinctions and what the fossil record tells us about angiosperm survival at K-Pg: a reply to Hagen (2024)

Last year, we published research using phylogenetic comparative methods (PCMs) to reveal no phylogenetic evidence for elevated lineage-level extinction rates in angiosperms across K-Pg (Thompson JB, Ramírez-Barahona S. 2023 No phylogenetic evidence for angiosperm mass extinction at the Cretaceous-Palaeogene (K-Pg) boundary. Biol. Lett. 19, 20230314. (doi:10.1098/rsbl.2023.0314)), results that are in step with the global angiosperm fossil record. In a critique of our paper (Hagen ER. 2024 A critique of Thompson and Ramírez-Barahona (2023) or: how I learned to stop worrying and love the fossil record. EcoEvoRxiv. (doi:10.32942/X2631W)), simulation work is presented to argue we erred in our methodological choices and interpretations, and that we should have deferred to fossil evidence. In our opinion, underlying this critique are poor methodological choices on simulations and philosophical problems surrounding the definition of a mass extinction event, which leads to incorrect interpretations of both the fossil record and PCMs. We further argue that deferring to one source of evidence in favour of the other shuts the door to important evolutionary and philosophical questions.

Global biogeographic regions for ants have complex relationships with those for plants and tetrapods

On a global scale, biodiversity is geographically structured into regions of biotic similarity. Delineating these regions has been mostly targeted for tetrapods and plants, but those for hyperdiverse groups such as insects are relatively unknown. Insects may have higher biogeographic congruence with plants than tetrapods due to their tight ecological and evolutionary links with the former, but it remains untested. Here, we develop a global regionalization for a major and widespread insect group, ants, based on the most comprehensive distributional and phylogenetic information to date, and examine its similarity to regionalizations for tetrapods and vascular plants. Our ant regionalization supports the newly proposed Madagascan and Sino-Japanese realms based on tetrapod delineations, and it recovers clusters observed in plants but not in tetrapods, such as the Holarctic and Indo-Pacific realms. Quantitative comparison suggests strong associations among different groups-plants showed a higher congruence with ants than with tetrapods. These results underscore the wide congruence of diverse distribution patterns across the tree of life and the similarities shared by insects and plants that are not captured by tetrapod groups. Our analysis highlights the importance of developing global biogeographic maps for insect groups to obtain a more comprehensive geographic picture of life on Earth.

Cenozoic seeds of Vitaceae reveal a deep history of extinction and dispersal in the Neotropics

The remarkably diverse plant communities of the Neotropics are the result of diversification driven by multiple biotic (for example, speciation, extinction and dispersal) and abiotic (for example, climatic and tectonic) processes. However, in the absence of a well-preserved, thoroughly sampled and critically assessed fossil record, the associated processes of dispersal and extinction are poorly understood. We report an exceptional case study documenting patterns of extinction in the grape family (Vitaceae Juss.) on the basis of fossil seeds discovered in four Neotropical palaeofloras dated between 60 and 19 Ma. These include a new species that provides the earliest evidence of Vitaceae in the Western Hemisphere. Eight additional species reveal the former presence of major clades of the family that are currently absent from the Neotropics and elucidate previously unknown dispersal events. Our results indicate that regional extinction and dispersal have substantially impacted the evolutionary history of Vitaceae in the Neotropics. They also suggest that while the Neotropics have been dynamic centres of diversification through the Cenozoic, extant Neotropical botanical diversity has also been shaped by extensive extinction over the past 66 million years.

Phylogenomic approaches reveal a robust time-scale phylogeny of the Terminal Fusarium Clade

The Terminal Fusarium Clade (TFC) is a group in the Nectriaceae family with agricultural and clinical relevance. In recent years, various phylogenies have been presented in the literature, showing disagreement in the topologies, but only a few studies have conducted analyses on the divergence time scale of the group. Therefore, the evolutionary history of this group is still being determined. This study aimed to understand the evolutionary history of the TFC from a phylogenomic perspective. To achieve this objective, we performed a phylogenomic analysis using the available genomes in GenBank and ran eight different pipelines. We presented a new robust topology of the TFC that differs at some nodes from previous studies. These new relationships allowed us to formulate new hypotheses about the evolutionary history of the TFC. We also inferred new divergence time estimates, which differ from those of previous studies due to topology discordances and taxon sampling. The results suggested an important diversification process in the Neogene period, likely associated with the diversification and predominance of terrestrial ecosystems by angiosperms. In conclusion, we presented a robust time-scale phylogeny that allowed us to formulate new hypotheses regarding the evolutionary history of the TFC.

Evolutionary radiation strategy revealed in the Scarabaeidae with evidence of continuous spatiotemporal morphology and phylogenesis

Evolutionary biology faces the important challenge of determining how to interpret the relationship between selection pressures and evolutionary radiation. The lack of morphological evidence on cross-species research adds to difficulty of this challenge. We proposed a new paradigm for evaluating the evolution of branches through changes in characters on continuous spatiotemporal scales, for better interpreting the impact of biotic/abiotic drivers on the evolutionary radiation. It reveals a causal link between morphological changes and selective pressures: consistent deformation signals for all tested characters on timeline, which provided strong support for the evolutionary hypothesis of relationship between scarabs and biotic/abiotic drivers; the evolutionary strategies under niche differentiation, which were manifested in the responsiveness degree of functional morphological characters with different selection pressure. This morphological information-driven integrative approach sheds light on the mechanism of macroevolution under different selection pressures and is applicable to more biodiversity research.

Parallel evolution of angiosperm-like venation in Peltaspermales: a reinvestigation of Furcula

Leaf venation is a pivotal trait in the success of vascular plants. Whereas gymnosperms have single or sparsely branched parallel veins, angiosperms developed a hierarchical structure of veins that form a complex reticulum. Its physiological consequences are considered to have enabled angiosperms to dominate terrestrial ecosystems in the Late Cretaceous and Cenozoic. Although a hierarchical-reticulate venation also occurs in some groups of extinct seed plants, it is unclear whether these are stem relatives of angiosperms or have evolved these traits in parallel. Here, we re-examine the morphology of the enigmatic foliage taxon Furcula, a potential early Mesozoic angiosperm relative, and argue that its hierarchical vein network represents convergent evolution (in the Late Triassic) with flowering plants (which developed in the Early Cretaceous) based on details of vein architecture and the absence of angiosperm-like stomata and guard cells. We suggest that its nearest relatives are Peltaspermales similar to Scytophyllum and Vittaephyllum, the latter being a genus that originated during the Late Triassic (Carnian) and shares a hierarchical vein system with Furcula. We further suggest that the evolution of hierarchical venation systems in the early Permian, the Late Triassic, and the Early Cretaceous represent 'natural experiments' that might help resolve the selective pressures enabling this trait to evolve.

Geographical patterns and determinants of insect biodiversity in China

Insects play important roles in the maintenance of ecosystem functioning and the provision of livelihoods for millions of people. However, compared with terrestrial vertebrates and angiosperms, such as the giant panda, crested ibis, and the metasequoia, insect conservation has not attracted enough attention, and a basic understanding of the geographical biodiversity patterns for major components of insects in China is lacking. Herein, we investigated the geographical distribution of insect biodiversity across multiple dimensions (taxonomic, genetic, and phylogenetic diversity) based on the spatial distribution and molecular DNA sequencing data of insects. Our analysis included 18 orders, 360 families, 5,275 genera, and 14,115 species of insects. The results revealed that Southwestern and Southeastern China harbored higher insect biodiversity and numerous older lineages, representing a museum, whereas regions located in Northwestern China harbored lower insect biodiversity and younger lineages, serving as an evolutionary cradle. We also observed that mean annual temperature and precipitation had significantly positive effects, whereas altitude had significantly negative effects on insect biodiversity in most cases. Moreover, cultivated vegetation harbored the highest insect taxonomic and phylogenetic diversity, and needleleaf and broadleaf mixed forests harbored the highest insect genetic diversity. These results indicated that human activities may positively contribute to insect spatial diversity on a regional scale. Our study fills a knowledge gap in insect spatial diversity in China. These findings could help guide national-level conservation plans and the post-2020 biodiversity conservation framework.

Meta-analysis reveals that the effects of precipitation change on soil and litter fauna in forests depend on body size

Anthropogenic climate change is altering precipitation regimes at a global scale. While precipitation changes have been linked to changes in the abundance and diversity of soil and litter invertebrate fauna in forests, general trends have remained elusive due to mixed results from primary studies. We used a meta-analysis based on 430 comparisons from 38 primary studies to address associated knowledge gaps, (i) quantifying impacts of precipitation change on forest soil and litter fauna abundance and diversity, (ii) exploring reasons for variation in impacts and (iii) examining biases affecting the realism and accuracy of experimental studies. Precipitation reductions led to a decrease of 39% in soil and litter fauna abundance, with a 35% increase in abundance under precipitation increases, while diversity impacts were smaller. A statistical model containing an interaction between body size and the magnitude of precipitation change showed that mesofauna (e.g. mites, collembola) responded most to changes in precipitation. Changes in taxonomic richness were related solely to the magnitude of precipitation change. Our results suggest that body size is related to the ability of a taxon to survive under drought conditions, or to benefit from high precipitation. We also found that most experiments manipulated precipitation in a way that aligns better with predicted extreme climatic events than with predicted average annual changes in precipitation and that the experimental plots used in experiments were likely too small to accurately capture changes for mobile taxa. The relationship between body size and response to precipitation found here has far-reaching implications for our ability to predict future responses of soil biodiversity to climate change and will help to produce more realistic mechanistic soil models which aim to simulate the responses of soils to global change.

Phylogenomics and the rise of the angiosperms

Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods1,2. A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome3,4. Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins5-7. However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes8. This 15-fold increase in genus-level sampling relative to comparable nuclear studies9 provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade.

Ant evolution: Amber revelations of extinction, survival and recovery

Ant fossils from the Cretaceous are rare but critical for understanding the early evolution of this incredibly successful group of animals. New amber fossils fill important gaps, revealing patterns of death, survival, and radiation around the end Cretaceous extinction.

Ongoing convergent evolution of a selfing syndrome threatens plant-pollinator interactions

Plant-pollinator interactions evolved early in the angiosperm radiation. Ongoing environmental changes are however leading to pollinator declines that may cause pollen limitation to plants and change the evolutionary pressures shaping plant mating systems. We used resurrection ecology methodology to contrast ancestors and contemporary descendants in four natural populations of the field pansy (Viola arvensis) in the Paris region (France), a depauperate pollinator environment. We combine population genetics analysis, phenotypic measurements and behavioural tests on a common garden experiment. Population genetics analysis reveals 27% increase in realized selfing rates in the field during this period. We documented trait evolution towards smaller and less conspicuous corollas, reduced nectar production and reduced attractiveness to bumblebees, with these trait shifts convergent across the four studied populations. We demonstrate the rapid evolution of a selfing syndrome in the four studied plant populations, associated with a weakening of the interactions with pollinators over the last three decades. This study demonstrates that plant mating systems can evolve rapidly in natural populations in the face of ongoing environmental changes. The rapid evolution towards a selfing syndrome may in turn further accelerate pollinator declines, in an eco-evolutionary feedback loop with broader implications to natural ecosystems.

Fern mycorrhizae do not respond to fertilization in a tropical montane forest

Ferns are known to have a lower incidence of mycorrhization than angiosperms. It has been suggested that this results from carbon being more limiting to fern growth than nutrient availability, but this assertion has not been tested yet. In the present study, we took advantage of a fertilization experiment with nitrogen and phosphorus on cloud forest plots of the Ecuadorean Andes for 15 years. A previous analysis revealed changes in the abundances of fern species in the fertilized plots compared to the control plots and hypothesized that this might be related to the responses of the mycorrhizal relationships to nutrient availability. We revisited the plots to assess the root-associated fungal communities of two epiphytic and two terrestrial fern species that showed shifts in abundance. We sampled and analyzed the roots of 125 individuals following a metabarcoding approach. We recovered 1382 fungal ASVs, with a dominance of members of Tremellales (Basidiomycota) and Heliotales (Ascomycota). The fungal diversity was highly partitioned with little overlap between individuals. We found marked differences between terrestrial and epiphytic species, with the latter fundamentally missing arbuscular mycorrhizal fungi (AMF). We found no effect of fertilization on the diversity or relative abundance of the fungal assemblages. Still, we observed a direct impact of phosphorus fertilization on its concentration in the fern leaves. We conclude that fern-fungi relationships in the study site are not restricted by nutrient availability and suggest the existence of little specificity on the fungal partners relative to the host fern species.

The Angiosperm Terrestrial Revolution buffered ants against extinction

With ~14,000 extant species, ants are ubiquitous and of tremendous ecological importance. They have undergone remarkable diversification throughout their evolutionary history. However, the drivers of their diversity dynamics are not well quantified or understood. Previous phylogenetic analyses have suggested patterns of diversity dynamics associated with the Angiosperm Terrestrial Revolution (ATR), but these studies have overlooked valuable information from the fossil record. To address this gap, we conducted a comprehensive analysis using a large dataset that includes both the ant fossil record (~24,000 individual occurrences) and neontological data (~14,000 occurrences), and tested four hypotheses proposed for ant diversification: co-diversification, competitive extinction, hyper-specialization, and buffered extinction. Taking into account biases in the fossil record, we found three distinct diversification periods (the latest Cretaceous, Eocene, and Oligo-Miocene) and one extinction period (Late Cretaceous). The competitive extinction hypothesis between stem and crown ants is not supported. Instead, we found support for the co-diversification, buffered extinction, and hyper-specialization hypotheses. The environmental changes of the ATR, mediated by the angiosperm radiation, likely played a critical role in buffering ants against extinction and favoring their diversification by providing new ecological niches, such as forest litter and arboreal nesting sites, and additional resources. We also hypothesize that the decline and extinction of stem ants during the Late Cretaceous was due to their hyper-specialized morphology, which limited their ability to expand their dietary niche in changing environments. This study highlights the importance of a holistic approach when studying the interplay between past environments and the evolutionary trajectories of organisms.

Disparity of cycad leaves dispels the living fossil metaphor

The living fossil metaphor is tightly linked with the cycads. This group of gymnosperms is supposed to be characterised by long-term morphological stasis, particularly after their peak of diversity and disparity in the Jurassic. However, no formal test of this hypothesis exists. Here, we use a recent phylogenetic framework and an improved character matrix to reconstruct the Disparity Through Time for cycad leaves using a Principal Coordinate Analysis and employing Pre-Ordination Ancestral State Reconstruction to test the impact of sampling on the results. Our analysis shows that the cycad leaf morsphospace expanded up to the present, with numerous shifts in its general positioning, independently of sampling biases. Moreover, they also show that Zamiaceae expanded rapidly in the Early Cretaceous and continued to expand up to the present, while now-extinct clades experienced a slow contraction from their peak in the Triassic. We also show that rates of evolution were constantly high up to the Early Cretaceous, and then experienced a slight decrease in the Paleogene, followed by a Neogene acceleration. These results show a much more dynamic history for cycads, and suggest that the 'living fossil' metaphor is actually a hindrance to our understanding of their macroevolution.

An evolutionary innovation for mating facilitates ecological niche expansion and buffers species against climate change

One of the drivers of life's diversification has been the emergence of "evolutionary innovations": The evolution of traits that grant access to underused ecological niches. Since ecological interactions can occur separately from mating, mating-related traits have not traditionally been considered factors in niche evolution. However, in order to persist in their environment, animals need to successfully mate just as much as they need to survive. Innovations that facilitate mating activity may therefore be an overlooked determinant of species' ecological limits. Here, we show that species' historical niches and responses to contemporary climate change are shaped by an innovation involved in mating-a waxy, ultra-violet-reflective pruinescence produced by male dragonflies. Physiological experiments in two species demonstrate that pruinescence reduces heating and water loss. Phylogenetic analyses show that pruinescence is gained after taxa begin adopting a thermohydrically stressful mating behavior. Further comparative analyses reveal that pruinose species are more likely to breed in exposed, open-canopy microhabitats. Biogeographic analyses uncover that pruinose species occupy warmer and drier regions in North America. Citizen-science observations of Pachydiplax longipennis suggest that the extent of pruinescence can be optimized to match the local conditions. Finally, temporal analyses indicate that pruinose species have been buffered against contemporary climate change. Overall, these historical and contemporary patterns show that successful mating can shape species' niche limits in the same way as growth and survival.