Niche Evolution Research Articles

The niche evolution of cross-boundary innovation for Chinese SMEs in the context of digital transformation——Case study based on dynamic capability

In the era of the digital economy, the cross-boundary innovation activities of many SMEs across industries and fields have become the focus of academic attention. However, existing studies have neglected to explore the evolutionary and development of cross-boundary innovation models from a process perspective. In particular, the induction and summary of the enterprise digital cross-boundary innovation path will provide guidance for the innovation and development of SEMs, which has become the core problem to be solved in this study. This study embeds dynamic capabilities into the evolution process of enterprise ecological niche. Through a qualitative study on the three cross-boundary processes of the digital publishing projects of traditional publishing enterprises under the background of digital transformation, it reveals the growth mechanism and evolution path of dynamic capability affecting enterprise niche change in the process of cross-boundary innovation of SMEs. The results show that:(1) Under the background of digital transformation, the niche structure of SMEs is influenced by technology factor, resource factor, demand factor, and network factor; (2) In the process of cross-boundary innovation, the coupling of enterprise multi-dimensional dynamic capability and niche factors drive the migration of enterprise niche; (3) The development path of cross-boundary innovation of SMEs is the process of niche dynamic adjustment, such as niche expansion, niche dislocation and niche construction. This research conclusion reveals the development law of cross-boundary innovation of SMEs, further enriches the research system of cross-boundary innovation and provides theoretical guidance for the digital transformation of SMEs and the implementation of cross-boundary development strategy.

Are Cenozoic relict species also climatic relicts? Insights from the macroecological evolution of the giant sedges of Carex sect. Rhynchocystis (Cyperaceae).

Most of the Paleotropical flora widely distributed in the Western Palearctic became extinct during the Mio-Pliocene as a result of global geoclimatic changes. A few elements from this Cenozoic flora are believed to remain as relicts in Macaronesia, forming part of the laurel forests. Although the origins of the present species assembly are known to be heterogeneous, it is unclear whether some species should be considered climatic relicts with conserved niches. An ideal group for studying such relict characteristics is a Miocene lineage of Carex sect. Rhynchocystis (Cyperaceae), which comprises four species distributed in mainland Palearctic and Macaronesia. We reconstructed the current and past environmental spaces for extant mainland and Macaronesian species, as well as for Pliocene fossils. We also studied the bioclimatic niche evolution. Species distribution modeling and ensemble small modeling were performed to assess the potential distribution over time. Climatic niche analyses and distribution modeling revealed that the ecological requirements of Macaronesian species did not overlap with those of either mainland species or with the Pliocene fossils. Conversely, the niches of mainland species displayed significant similarity and equivalence. Macaronesian species are not climatic relicts from the Paleotropical flora, but instead seem to have changed the ecological niche of their ancestors. By contrast, despite their ancient divergence (Late Miocene), mainland C. pendula and C. agastachys show conserved niches, with competitive exclusion likely shaping their mostly allopatric ranges.

The role of proximity in sustainability transitions: A technological niche evolution analysis

The transition literature (especially within economic geography, urban studies and political ecology) highlights that the proximity between actors plays a crucial role in determining the dynamics of sustainable transitions. Economic geographers distinguish between absolute (spatial) and relative (non-spatial) proximity. These play different roles in the transition process, though relative proximity has been scarcely investigated in empirical studies. To overcome this limitation, we investigated the relevance of spatial and non-spatial proximity in the evolution of a technological niche. We also explored the roles of different kinds of non-spatial proximity (i.e. cognitive, organizational, social, institutional), in niche evolution, in terms of network expansion. To this end, we analyzed the Italian biofuel niche, as it has already undergone different evolution phases. We found that the most relevant drivers of niche networking were social, cognitive and institutional proximity. Additionally, while social proximity was relevant throughout the entire life span of the niche, cognitive and institutional proximity gained significance only in the maturity phase, marking a transition point in the niche evolution. From these findings we derive that policy makers should (i) concentrate on social proximity to speed up niche evolution and (ii) increase cognitive and institutional proximity in the development phase in order to consolidate the niche in the maturity phase. This could occur through initiatives aimed at creating common experiences (e.g. business incubators, technological communities) and the intervention of national and/or supranational institutions to create network externality conditions by means of R&D subsidies.

The evolution of niche: variety in knowledge networks in the global music industry

ABSTRACT This paper examines the evolution of niches in creative industries, specifically the music industry. We conceptualise niche evolution as a manifestation of Schumpeterian disruption, and the music scene as a representation of a creative niche. Through mixed methods, we analyse niche evolution in collaboration networks over sixty years. We show that niche evolution exhibits recombination and reinforcement of new ideas, and propose that niche emergence and evolution in the music industry can be categorised as following three different pathways: seed fragmentation networks with early recombination and intermediate-stage reinforcement, often resulting from break-ups of highly influential bands; creative horizontal networks with intermediate-stage recombination and reinforcement, consisting of tightly knit communities with delayed commercial breakthroughs; and artist experimentation networks with late recombination and reinforcement, consisting of small niches of sub-genre innovations. This paper opens up new research directions for niche evolution, which can advance understanding of knowledge-intensive innovation ecosystems in other sectors.

Linking mode of seed dispersal and climatic niche evolution in flowering plants

AbstractAimDue to the sessile nature of flowering plants, movements to new geographical areas occur mainly during seed dispersal. Frugivores tend to be efficient dispersers because animals move within the boundaries of their preferable niches, so seeds are more likely to be transported to environments that are similar to where the parent plant occurs. However, this efficiency can result in less opportunity for niche shifts over macroevolutionary time, ‘trapping’ plant lineages in particular climatic conditions. Here we test this hypothesis by analysing the role that the interaction with frugivores play in changing dynamics of climatic niche evolution in five clades of flowering plants.LocationGlobal.TaxonThe flowering plant families Apocynaceae, Ericaceae, Melastomataceae, Rosaceae and Solanaceae.MethodsWe model climatic niche evolution as a variable parameter Ornstein–Uhlenbeck process. However, rather than assuming regimes a priori, we use a hidden Markov model (HMM) to infer the complex evolutionary history associated with different modes of seed dispersal. In addition to allowing for a more accurate picture of the regimes, the use of HMMs allows partitioning the variance of climatic niche evolution to include dynamics independent of our focal character.ResultsLineages dispersed by frugivores tend to have warmer and wetter climatic optima and are generally associated with areas where potential for vegetation growth is higher. However, lineages distributed in more mesic habitats, such as rainforests, are generally associated with slower rates of climatic niche evolution regardless of their mode of seed dispersal.Main ConclusionsCharacteristics of the abiotic environment may facilitate the evolution of some types of plant–animal interactions. Association with frugivores is an important modulator of how plants move in space, but its impact on their climatic niche evolution appears to be indirect. Seed dispersal by frugivores may facilitate the establishment of lineages in closed canopy biomes, but the general slower rates of climatic niche evolution in these habitats are possibly related to other general aspects of the ‘mesic syndrome’ rather than the behaviour of the animals that disperse their seeds.

Neotropical niche evolution of Otoba trees in the context of global biogeography of the nutmeg family

AbstractAimPlant distributions are influenced by species’ ability to colonize new areas via long‐distance dispersal and propensity to adapt to new environments via niche evolution. We use otobas, a clade of ecologically dominant trees found in low‐to mid‐elevation wet forests, as a system to understand the relative importance of these processes within the Neotropics.LocationNeotropics and global.TaxonOtoba and entire Myristicaceae.MethodsWe resolve the first phylogeny of Otoba the Angiosperms353 loci and plastome sequences from 13 accessions representing seven species. We pair this with the most densely sampled phylogeny of Myristicaceae to date, inferred using publicly available plastid data. We then use environmental niche modelling, biogeographical reconstruction, phylogenetic principle components analysis and Ornstein–Uhlenbeck models to infer biogeography and examine patterns of niche evolution.ResultsMyristicaceae has an Old World origin, with a single expansion into the Americas. Divergence dates, fossil evidence and a notable lack of long‐distance dispersal are consistent with a Boreotropical origin of Neotropical Myristicaceae. Mirroring the rarity of dispersal at the family level, Otoba's biogeography is marked by few biogeographical events: two expansions into Central America from a South American ancestor and a single dispersal event across the Andes. This limited movement contrasts with rapid climatic niche evolution, typically occurring across geographically proximate habitats.Main conclusionContrasting with previous studies, long‐distance dispersal does not need to be invoked to explain the pantropical distribution of Myristicaceae, nor the biogeography of Otoba. This likely results from the family's relatively large seeds that are dispersed by large‐bodied vertebrates. Instead, rapid niche evolution in Otoba has facilitated its occurrence throughout mesic habitats of the northern Neotropics, including the Amazon rainforest and Andean montane forests. Otoba adds to a growing group of Neotropical plant clades in which climate adaptation following local migration is common, implying an important role of niche evolution in the assembly of the Neotropical flora.

Evolution of Short Food Supply Chain Innovation Niches and Its Anchoring to the Socio-Technical Regime: The Case of Direct Selling through Collective Action in North-West Portugal

This paper employs MLP (Multi Level Perspective) applied to a study on the transition to SFSC (short food supply chain) innovation taking place in North-West Portugal. MLP allows capturing transition phenomena and analysing them from a perspective that posits intervening factors and events on a three-level scale. Emphasis is laid on the institutional actors and factors that influence these processes, namely the Three Interrelated Analytic Dimensions and Types of Anchoring. Methodologically, personal interviews were conducted with 34 farmers who either are carrying out SFSC initiatives, or have dropped out, or even have never considered participating in them. A process of anchoring the innovation to the local socio-technical regime has been identified, characterised by a low buy-in from institutions and stakeholders. The anchoring that has been found has the peculiarity of occurring only in some points of the intersection between niche and regime, in a process in which it survives bordering this threshold, thanks to the mobilisation of multiple innovations. This type of anchoring, not yet described in the literature, draws attention to a possible pathway that innovations can follow, and brings implications for projects and for policy proposals to support the agroecological transition.

Phylogenetic conservation and shifts of pollination niche in generalist epiphytic cacti

Plant-pollinator interactions are influenced, among other factors, by evolutionary history of the organisms. Thus, closely related species are expected to interact with similar pollinator assemblages. The aim of this study was to examine the evolution of pollination niches in neotropical epiphytic cacti. We recorded floral visitors and determined the pollination niche of 11 species of Rhipsalis and one species of Hatiora by using bipartite modularity, a metric of complex networks that is effective to identify pollination niches. Afterwards we explored how these niches evolved along the phylogeny of Rhipsalis. We recorded a total of 56 insect species belonging to nine functional groups pollinating those species of Rhipsalis. The most frequent floral visitors were bees. Pollination systems in Rhipsalis broadly combined a high phenotypic floral generalization with moderate richness of pollinator species and some functional pollinator group specialization. Four pollination niches were identified, mainly characterized by variations in the frequency of the functional groups of pollinators. The closer the species of Rhipsalis were, the more they interacted with the same functional groups of pollinators, as indicated by a positive phylogenetic signal for pollinating niches. The most likely ancestral pollination niche was associated with short-tongued bees. From the niche defined by small bees at least three shifts occurred towards the niches defined by extra-small bees, short-tongued medium bees, and flies. Considering the perspective of the evolution of each pollinator group, short-tongued bees were conserved along the branches of Rhipsalis phylogeny, with niche broadening or shifts associated with other groups such as flies, large bees, wasps, beetles and butterflies. Distinct generalist pollination niches have evolved in the genus. Shifts in pollination niches were related to differences in floral morphology. Moreover, the distribution of pollination niches only partially corresponded to the infrageneric classification of Rhipsalis. Our results support that generalist pollination systems encompass different pollinating niches, which may be consistently distributed across clades in angiosperm lineages.

An Evolutionary Study of Carex Subg. Psyllophorae (Cyperaceae) Sheds Light on a Strikingly Disjunct Distribution in the Southern Hemisphere, With Emphasis on Its Patagonian Diversification.

Carex subgenus Psyllophorae is an engaging study group due to its early diversification compared to most Carex lineages, and its remarkable disjunct distribution in four continents corresponding to three independent sections: sect. Psyllophorae in Western Palearctic, sect. Schoenoxiphium in Afrotropical region, and sect. Junciformes in South America (SA) and SW Pacific. The latter section is mainly distributed in Patagonia and the Andes, where it is one of the few Carex groups with a significant in situ diversification. We assess the role of historical geo-climatic events in the evolutionary history of the group, particularly intercontinental colonization events and diversification processes, with an emphasis on SA. We performed an integrative study using phylogenetic (four DNA regions), divergence times, diversification rates, biogeographic reconstruction, and bioclimatic niche evolution analyses. The crown age of subg. Psyllophorae (early Miocene) supports this lineage as one of the oldest within Carex. The diversification rate probably decreased over time in the whole subgenus. Geography seems to have played a primary role in the diversification of subg. Psyllophorae. Inferred divergence times imply a diversification scenario away from primary Gondwanan vicariance hypotheses and suggest long-distance dispersal-mediated allopatric diversification. Section Junciformes remained in Northern Patagonia since its divergence until Plio-Pleistocene glaciations. Andean orogeny appears to have acted as a northward corridor, which contrasts with the general pattern of North-to-South migration for temperate-adapted organisms. A striking niche conservatism characterizes the evolution of this section. Colonization of the SW Pacific took place on a single long-distance dispersal event from SA. The little ecological changes involved in the trans-Pacific disjunction imply the preadaptation of the group prior to the colonization of the SW Pacific. The high species number of the section results from simple accumulation of morphological changes (disparification), rather than shifts in ecological niche related to increased diversification rates (radiation).

Climate Change Estimates Surpass Rates of Climatic Niche Evolution in Primates

Primates might be particularly vulnerable to experiencing adverse effects from climate change, given their level of exposure, sensitivity to climatic conditions, and biological traits associated with extinction proneness (e.g., low dispersal ability). Therefore, a key question is whether primates will be able to adapt fast enough to keep up with future climate change. In this study, we used phylogenetic comparative methods to estimate rates of climatic niche evolution for 293 species of primates. We then compared these with projected rates of future climate change. We show that for temperature-related variables, future rates are in general >2800 times faster than rates of niche evolution characteristic of their recent evolutionary past. For precipitation-related variables, the overall difference between rates is >6700. If emissions continue unabated, differences between past and future rates can be at least 4800-fold for temperature-related variables and >7900-fold for precipitation. Species occurring in Central South America, Central and Eastern Africa, Southeast Asia, and the Malay Archipelago are expected to experience the fastest rates of future climate change, relative to their past rates of climatic niche evolution. Our results suggest that primate adaptation to future climate change would require rates of niche evolution unparalleled in the recent history of the group. These findings reinforce the evidence that climate change is a major threat to primates worldwide.

Seed dispersal by wind decreases when plants are water-stressed, potentially counteracting species coexistence and niche evolution.

Hydrology is a major environmental factor determining plant fitness, and hydrological niche segregation (HNS) has been widely used to explain species coexistence. Nevertheless, the distribution of plant species along hydrological gradients does not only depend on their hydrological niches but also depend on their seed dispersal, with dispersal either weakening or reinforcing the effects of HNS on coexistence. However, it is poorly understood how seed dispersal responds to hydrological conditions. To close this gap, we conducted a common‐garden experiment exposing five wind‐dispersed plant species (Bellis perennis, Chenopodium album, Crepis sancta, Hypochaeris glabra, and Hypochaeris radicata) to different hydrological conditions. We quantified the effects of hydrological conditions on seed production and dispersal traits, and simulated seed dispersal distances with a mechanistic dispersal model. We found species‐specific responses of seed production, seed dispersal traits, and predicted dispersal distances to hydrological conditions. Despite these species‐specific responses, there was a general positive relationship between seed production and dispersal distance: Plants growing in favorable hydrological conditions not only produce more seeds but also disperse them over longer distances. This arises mostly because plants growing in favorable environments grow taller and thus disperse their seeds over longer distances. We postulate that the positive relationship between seed production and dispersal may reduce the concentration of each species to the environments favorable for it, thus counteracting species coexistence. Moreover, the resulting asymmetrical gene flow from favorable to stressful habitats may slow down the microevolution of hydrological niches, causing evolutionary niche conservatism. Accounting for context‐dependent seed dispersal should thus improve ecological and evolutionary models for the spatial dynamics of plant populations and communities.

Global cultivation of wheat crops induces considerable shifts in the range and niche of species relative to their wild progenitors

Species’ range and niche play key roles in understanding ecological and biogeographical patterns, especially in projecting global biotic homogenization and potential distribution patterns of species under global change scenarios. However, few studies have investigated the ability of crop cultivation to influence potential range sizes and niche shifts of species. Wheat and its wild progenitors share the same origin and evolutionary history, and thus provide an excellent system to explore this topic. Using ensembled ecological niche models and niche dynamic models, we studied the potential range sizes of wheat and its wild progenitors, as well as their niche dynamics. Our results showed that wheat had larger range size and niche breadth than its wild progenitors, suggesting that wheat cultivation is a more powerful driver of range and niche expansion than natural niche evolution. Additionally, wheat and its wild progenitors occupied different niche positions, and the former did not conserve the niches inherited from the latter, implying that wheat cultivation considerably induces niche shifts. The niche dynamics between wheat and its wild progenitors were not only closely associated with cultivation but were also modified by the niche conservatism of its wild progenitors. In contrast to most invasive plants, wheat, as a global staple crop species, did not conserve the niche space inherited from its wild progenitors, suggesting that compared with most plant invasions, cultivation may have a stronger effect on niche shifts. Therefore, global niche shifts induced by crop cultivation need much more attention, though the underlying mechanisms require further study.

Tracking the xeric biomes of South America: The spatiotemporal diversification of Mandacaru cactus

AbstractAimThe interconnectedness and biotic interchange among Neotropical biomes are thought to play an important role in driving adaptation and diversification. However, how these processes are in synteny to trait evolution in species of open and xeric areas is poorly studied. Here, we investigate the spatial and temporal dimensions of evolution and candidate traits associated with biome shifts in xeric vegetation, focusing on the family Cactaceae.LocationXeric and open areas of South America.TaxonGenus Cereus Mill. (Cactaceae, Cereeae).MethodsWe applied biogeographical reconstructions on a time‐calibrated phylogeny inferred from multilocus data (ddRAD‐Seq) using Bayesian analyses on BEAST2, species distribution modelling in Maxent, the reconstruction of biome affinities and niche shift analyses based on abiotic traits (climate and soil) using Mk‐model in BioGeoBEARS, and phenotypic trait‐based analysis in Mesquite.ResultsThe Cerrado domain is the ancestral area of Cereus, with most diversification events occurring in a time of intense orogenesis, climatic changes, and marine regressions within the last 5 Mya. Events of biome transition from the seasonally dry tropical forest (SDTF) were also associated with trait and niche shifts.Main conclusionsThe diversification of the xerophyte genus Cereus is associated with the climatic and geomorphological instabilities of the Pliocene and Pleistocene epochs. The Cerrado domain states an important region of dispersal for the genus. Some geographical range movements involved biome shifts associated with niche evolution while others were restricted to a simple biogeographical transition without niche change. Particular clades that experienced biome shifts displayed some phenotypic state changes, suggesting a role of biotic traits for environment transition. The results observed in Cereus may be a biogeographical pattern that should be tested with other cactus species, such as Pilosocereus spp., or species of xeric habitats, such as Annonaceae and Vochysiaceae.

Reduced host‐plant specialization is associated with the rapid range expansion of a Mediterranean butterfly

AbstractAimSpecies ranges are highly dynamic, shifting in space and time as a result of complex ecological and evolutionary processes. Disentangling the relative contribution of both processes is challenging but of primary importance for forecasting species distributions under climate change. Here, we use the spectacular range expansion (ca. 1000 km poleward shift within 10 years) of the butterfly Pieris mannii to unravel the factors underlying range dynamics, specifically the role of (i) niche evolution (changes in host‐plant preference and acceptance) and (ii) ecological processes (climate change).LocationProvence‐Alpes‐Côte d’Azur, France; North Rhine‐Westphalia, Rhineland‐Palatinate and Hesse, Germany.TaxonInsect and angiosperms.MethodsWe employed a combination of (i) common garden experiments, based on replicated populations from the species’ historical and newly established range and host‐plant species representative for each distribution range, co‐occurrence analyses and (ii) grid‐based correlative species distribution modelling (SDM) using Maxent.ResultsWe observed changes in oviposition preference, with females from the newly established populations showing reduced host‐plant specialization and also an overall increased fecundity. These changes in behaviour and life history may have enabled using a broader range of habitats and thus facilitated the recent range expansion. In contrast, our results indicate that the range expansion is unlikely to be directly caused by anthropogenic climate change, as the range was not constrained by climate in the first place.Main conclusionsWe conclude that evolution of a broader dietary niche rather than climate change is associated with the rapid range expansion, and discuss potential indirect consequences of climate change as trigger for the genetic differences found. Our study thus illustrates the importance of species interactions in shaping species distributions and range shifts, and draws attention to indirect effects of climate change. Embracing this complexity is likely the key to a better understanding of range dynamics.

New distributional opportunities with niche innovation in Eurasian snowfinches

This study explores the evolutionary history of ecological niche characters in the Eurasian snowfinch lineage. Specifically, we use new analytical approaches to reconstruct ecological niche evolution, taking into account uncertainty in knowledge of the ecological niche limits. We found an overall pattern of niche conservatism in relation to both temperature and precipitation characteristics of niches, but for one dramatic niche evolution event, in Montifringilla nivalis. Interestingly, this species is also that which has the broadest geographic distribution among snowfinches. We conclude that an evolutionary change in niche characteristics perhaps within M. nivalis (i.e. present in some and not all of its populations) made possible the broad, westward range expansion of that species, thus changing dramatically the distributional potential of the snowfinch lineage.

Transvaginal Sonographic Evaluation of Cesarean Section Scar Niche in Pregnancy: A Prospective Longitudinal Study

Background and Objectives: To investigate the prevalence of a Cesarean section (CS) scar niche during pregnancy, assessed by transvaginal ultrasound imaging, and to relate scar measurements, demographic and obstetric variables to the niche evolution and final pregnancy outcome. Materials and Methods: In this prospective observational study, we used transvaginal sonography to examine the uterine scars of 122 women at 11+0–13+6, 18+0–20+6 and 32+0–35+6 weeks of gestation. A scar was defined as visible on pregnant status when the area of hypoechogenic myometrial discontinuity of the lower uterine segment was identified. The CS scar niche (“defect”) was defined as an indentation at the site of the CS scar with a depth of at least 2 mm in the sagittal plane. We measured the hypoechogenic part of the CS niche in two dimensions, as myometrial thickness adjacent to the niche and the residual myometrial thickness (RMT). In the second and third trimesters of pregnancy, the full lower uterine segment (LUS) thickness and the myometrial layer thickness were measured at the thinnest part of the scar area. Two independent examiners measured CS scars in a non-selected subset of patients (n = 24). Descriptive analysis was used to assess scar visibility, and the intraclass correlation coefficient (ICC) was calculated to show the strength of absolute agreement between two examiners for scar measurements. Factors associated with the CS scar niche, including maternal age, BMI, smoking status, previous vaginal delivery, obstetrics complications and a history of previous uterine curettage, were investigated. Clinical information about pregnancy outcomes and complications was obtained from the hospital’s electronic medical database. Results: The scar was visible in 77.9% of the women. Among those with a visible CS scar, the incidence of a CS scar niche was 51.6%. The intra- and interobserver agreement for CS scar niche measurements was excellent (ICC 0.98 and 0.89, respectively). Comparing subgroups of women in terms of CS scar niche (n = 49) and non-niche (n = 73), there was no statistically significant correlation between maternal age (p = 0.486), BMI (p = 0.529), gestational diabetes (p = 1.000), smoking status (p = 0.662), previous vaginal delivery after CS (p = 1.000) and niche development. Uterine scar niches were seen in 56.3% (18/48) of the women who had undergone uterine curettage, compared with 34.4% (31/74) without uterine curettage (p = 0.045). We observed an absence of correlation between the uterine scar niche at the first trimester of pregnancy and mode of delivery (p = 0.337). Two cases (4.7%) of uterine scar dehiscence were confirmed following a trial of vaginal delivery. Conclusions: Based on ultrasonography examination, the CS scar niche remained visible in half of the cases with a visible CS scar at the first trimester of pregnancy and could be reproducibly measured by a transvaginal scan. Previous uterine curettage was associated with an increased risk for uterine niche formation in a subsequent pregnancy. Uterine scar dehiscence might be potentially related to the CS scar niche.

Niche evolution and historical biogeography of lady slipper orchids in North America and Eurasia

AbstractAimDispersal and subsequent adaptation to local environmental and climatic conditions play major roles in the evolution and current‐day distribution of plants and animals, but their relative importance is not always easy to disentangle. The aim of this study was to provide a comprehensive phylogenetic analysis of the terrestrial orchid genus Cypripedium to better understand the role of niche evolution and historical dispersal events in driving the radiation of the genus in North America and Eurasia.LocationNorthern Hemisphere.TaxonCypripedium (Orchidaceae).MethodsWe used a relaxed molecular clock analysis to infer phylogenetic relationships among 45 Cypripedium species and to estimate divergence times. Niche modelling was used to assess the potential distribution of each species in both continents, whereas ancestral area reconstructions using BioGeoBEARS were used to estimate changes in historical biogeography. Subsequently, the ancestral state of niche conditions was assessed for each species using maximum likelihood methods and we tested for phylogenetic signal in the evolution of niche conditions using Blomberg's K and Pagel's λ. A mantel test was used to test for a correlation between phylogenetic distances and niche overlap in Cypripedium.ResultsWe found that Cypripedium originated in Central America and underwent multiple dispersal events between North America and Eurasia after long‐distance seed dispersal or dispersal via the Bering land bridge. The mountainous area of Southwest China provided refuge areas for Cypripedium orchids during episodes of increased glaciation. Our results further showed that Cypripedium has gradually increased its tolerance to seasonal temperature changes, providing evidence for significant niche evolution through time. No significant correlation between current niches and phylogenetic relatedness was observed.Main conclusionsOur study provides clear evidence that repeated dispersal and adaptation to increased cooling after the Eocene−Oligocene Transition has contributed to the radiation of Cypripedium in the Northern Hemisphere.

Earth history events shaped the evolution of uneven biodiversity across tropical moist forests

Far from a uniform band, the biodiversity found across Earth's tropical moist forests varies widely between the high diversity of the Neotropics and Indomalaya and the relatively lower diversity of the Afrotropics. Explanations for this variation across different regions, the "pantropical diversity disparity" (PDD), remain contentious, due to difficulty teasing apart the effects of contemporary climate and paleoenvironmental history. Here, we assess the ubiquity of the PDD in over 150,000 species of terrestrial plants and vertebrates and investigate the relationship between the present-day climate and patterns of species richness. We then investigate the consequences of paleoenvironmental dynamics on the emergence of biodiversity gradients using a spatially explicit model of diversification coupled with paleoenvironmental and plate tectonic reconstructions. Contemporary climate is insufficient in explaining the PDD; instead, a simple model of diversification and temperature niche evolution coupled with paleoaridity constraints is successful in reproducing the variation in species richness and phylogenetic diversity seen repeatedly among plant and animal taxa, suggesting a prevalent role of paleoenvironmental dynamics in combination with niche conservatism. The model indicates that high biodiversity in Neotropical and Indomalayan moist forests is driven by complex macroevolutionary dynamics associated with mountain uplift. In contrast, lower diversity in Afrotropical forests is associated with lower speciation rates and higher extinction rates driven by sustained aridification over the Cenozoic. Our analyses provide a mechanistic understanding of the emergence of uneven diversity in tropical moist forests across 110 Ma of Earth's history, highlighting the importance of deep-time paleoenvironmental legacies in determining biodiversity patterns.

Incongruences between nuclear and plastid phylogenies challenge the identification of correlates of diversification in Gentiana in the European Alpine System

Mountains are reservoirs for a tremendous biodiversity which was fostered by a suite of factors acting in concert throughout evolutionary times. These factors can be climatic, geological, or biotic, but the way they combine through time to generate diversity remains unknown. Here, we investigate these factors as correlates of diversification of three closely related sections of Gentiana in the European Alpine System. Based upon phylogenetic approaches coupled with divergence dating and ancestral state reconstructions, we attempted to identify the role of bedrock preferences, chromosome numbers coupled with relative genome sizes estimates, as well as morphological features through time. We also investigated extant climatic preferences using a heavily curated set of occurrence records individually selected for superior precision, and quantified rates of climatic niche evolution in each section. We found that a number of phylogenetic incongruences derail the identification of correlates of diversification, yet a number of patterns persist regardless of the topology considered. All the studied correlates are likely to have contributed to the diversification of Gentiana in Europe, however, their respective importance varied through time and across clades. Chromosomal variation and divergence of climatic preferences appear to correlate with diversification throughout the evolution of European Gentiana (Oligocene to present), whereas shifts in bedrock preferences appear to have been more defining during recent diversification (Pliocene). Overall, a complex interaction among climatic, geological and biotic attributes appear to have supported the diversification of Gentiana across the mountains of Europe, which based upon phylogenetic as well as other evidence, was probably also bolstered by hybridization.

Low size dimorphism does not lead to reduced sexual segregation: exploring effects of habitat divergence and activity

While the proximate and ultimate causes of sexual segregation have been well studied over the past 30 years, most of the research has focused on species with a pronounced sexual size dimorphism. Species with a smaller size dimorphism are probably understudied, because the assumption is that aggregation rather than sex segregation should be the norm. We used 6 years of direct observations of goitered gazelles, Gazella subgutturosa , an ungulate with a small degree of sexual size dimorphism, to explore sexual segregation and aggregation patterns and habitat choice at two timescales. We predicted minimal differences in activity budgets between the sexes, based on their small size dimorphism, and did not expect any evolutionary niche divergence based on size. However, we found that goitered gazelles showed considerable sexual and habitat segregation for most of the year, and only showed a tendency to randomly aggregate during the peak of the rutting season. We also found that they segregated socially and by habitat and had different activity budgets in some months. Behavioural asynchrony and sexual differences in habitat use were much greater than predicted for a species with such a small sexual dimorphism in body size. Our study confirms strong multifactorial sexual segregation patterns, and points to the potential importance that social factors (aggression and territoriality) may have on sexual segregation in goitered gazelles. • Studies on sexual segregation mostly focus on highly sexual size-dimorphic species. • High degree of sexual segregation was found in a less size-dimorphic species. • Both habitat differentiation and activity are associated with sexual segregation. • Goitered gazelles exhibit multifactorial segregation patterns.