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Colonization of a new environment may trigger an evolutionary radiation, defined as an accelerated accumulation of species in a short period of time. However, how often colonization events trigger such radiations is still an open question. We studied the worldwide dispersal of Caninae to investigate whether the invasion of new continents resulted in elevated species diversification. We used a combination of ancestral range estimation and phylogenetic analyses to estimate the ancestral ranges of 56 extant and extinct species of Caninae, as well as variation in speciation and extinction rates through time and across clades. Our findings indicate that canids experienced an evolutionary radiation event when lineages were able to reach Eurasia and South America around 11 million years ago. A large number of species arising in a short period of time suggests that canids experienced ecological opportunity events within the new areas, implying that the differences in the ecological settings between continents, and size variation among Canidae and other carnivores may be responsible for the variation in clade dynamics. We suggest that the increase of grasslands and the new herbivorous fauna that came with it were the major forces responsible for the diversification of wolves in North America, while empty niches and the absence of competitors can explain the success of canids in Africa and South America. Interaction with other carnivores probably also affected the diversification dynamics of canids.

Native plant communities are commonly invaded by invasive plants to different degrees. However, the relative contribution of the invasive plant abundance vs. phylogenetic evenness to the responses of wetland communities to different degrees of invasion is still unclear. In addition, whether such contribution varies with environmental conditions such as flooding is also unclear. To address these questions, we chose Alternanthera philoxeroides as the invasive plant, and set up four invasive degrees by changing the community species composition under both flooding and non-flooding conditions. The relative abundance of A. philoxeroides and phylogenetic evenness changed simultaneously with the change in the community invasion degree. The invasion degree significantly affected the individual biomass of A. philoxeroides and some native species. Variation partitioning showed that the relative abundance of A. philoxeroides contributed more to variation in community indicators than phylogenetic evenness, regardless of flooding. Spearman rank correlation test showed that the relative abundance of A. philoxeroides was negatively correlated with the individual biomass of A. philoxeroides and some native species, while the phylogenetic evenness was positively correlated with only a few native species. And their correlation strength and significance were all affected by specific species and flooded environment. In conclusion, our results suggest that the relative abundance of A. philoxeroides can more effectively explain the wetland community response to different invasion degrees than phylogenetic evenness, regardless of flooding.

The impact of climate change on global biodiversity is firmly established, but the differential effect of climate change on populations within the same species is rarely considered. In ectotherms, melanism (i.e. darker integument due to heavier deposition of melanin) can significantly influence thermoregulation, as dark individuals generally heat more and faster than bright ones. Therefore, darker ectotherms might be more susceptible to climate change. Using the colour-polyphenic lizard Karusasaurus polyzonus (Squamata: Cordylidae), we hypothesized that, under future climatic projections, darker populations will decrease their activity time more than brighter ones due to their greater potential for overheating. To test this, we mechanistically modelled the body temperatures of 56 individuals from five differently coloured populations under present and future climate conditions. We first measured morphological traits and integumentary reflectance from live animals, and then collected physiological data from the literature. We used a biophysical model to compute activity time of individual lizards as proxy for their viability, and thereby predict how different populations will cope with future climate conditions. Contrary to our expectations, we found that all populations will increase activity time and, specifically, that darker populations will become relatively more active than bright ones. This suggests that darker populations of K. polyzonus may benefit from global warming. Our study emphasizes the importance of accounting for variation between populations when studying responses to climate change, as we must consider these variations to develop efficient and specific conservation strategies. A free Plain Language Summary can be found within the Supporting Information of this article.

Background and Aims The Canary Islands have strong floristic affinities with the Mediterranean Basin. One of the most characteristic and diverse vegetation belts of the archipelago is the thermophilous woodland (between 200 and 900 m.a.s.l.). This thermophilous plant community consists of many non-endemic species shared with the Mediterranean Floristic Region together with Canarian endemic species. Consequently, phytogeographic studies have historically proposed the hypothesis of an origin of the Canarian thermophilous species following the establishment of the summer-dry mediterranean climate in the Mediterranean Basin around 2.8 million years ago. Methods Time-calibrated phylogenies for 39 plant groups including Canarian thermophilous species were primarily analysed to infer colonization times. In particular, we used 26 previously published phylogenies together with 13 new time-calibrated phylogenies (including newly generated plastid and nuclear DNA sequence data) to assess whether the time interval between stem and crown ages of Canarian thermophilous lineages postdates 2.8 Ma. For lineages postdating this time threshold, we additionally conducted ancestral area reconstructions to infer the potential source area for colonization. Key Results A total of 43 Canarian thermophilous lineages were identified from 39 plant groups. Both mediterranean (16) and pre-mediterranean (9) plant lineages were found. However, we failed to determine the temporal origin for 18 lineages because a stem–crown time interval overlaps with the 2.8-Ma threshold. The spatial origin of thermophilous lineages was also heterogeneous, including ancestral areas from the Mediterranean Basin (nine) and other regions (six). Conclusions Our findings reveal an unexpectedly heterogeneous origin of the Canarian thermophilous species in terms of colonization times and mainland source areas. A substantial proportion of the lineages arrived in the Canaries before the summer-dry climate was established in the Mediterranean Basin. The complex temporal and geographic origin of Canarian thermophilous species challenges the view of the Canary Islands (and Madeira) as a subregion within the Mediterranean Floristic Region.

Adaptive radiation is proposed to play a key role in generating differences in species richness among lineages and geographical regions. Due to the importance of ecological divergence in adaptive radiation, species richness is predicted to be influenced by equilibrium diversity dynamics, although the concept continues to generate much debate. An additional important question is whether radiating clades have intrinsic biological characteristics that make them particularly prone to diversify. We tackle these questions by analysing (i) the temporal patterns of diversification of Caribbean Eleutherodactylus frogs, and (ii) assembly of the complete native anuran community of the Caribbean archipelago (197 species), testing for the presence of equilibrium dynamics and whether diversification patterns of Eleutherodactylus differ from those of the rest of the Caribbean anurans. Diversification rates follow the predicted pattern of rapid diversification early in the radiation which gradually decreases towards the present. Eleutherodactylus diversification is significantly faster than that of the Caribbean anuran community, and although equilibrium dynamics influence richness of all Caribbean anurans, Eleutherodactylus shows higher carrying capacity. Our results indicate that ecological opportunity per se is not sufficient for adaptive radiation and that diverse lineages present intrinsic characteristics that enable them to make the most of available opportunity.

Many of Madagascar’s unique species are threatened with extinction. However, the severity of recent and potential extinctions in a global evolutionary context is unquantified. Here, we compile a phylogenetic dataset for the complete non-marine mammalian biota of Madagascar and estimate natural rates of extinction, colonization, and speciation. We measure how long it would take to restore Madagascar’s mammalian biodiversity under these rates, the “evolutionary return time” (ERT). At the time of human arrival there were approximately 250 species of mammals on Madagascar, resulting from 33 colonisation events (28 by bats), but at least 30 of these species have gone extinct since then. We show that the loss of currently threatened species would have a much deeper long-term impact than all the extinctions since human arrival. A return from current to pre-human diversity would take 1.6 million years (Myr) for bats, and 2.9 Myr for non-volant mammals. However, if species currently classified as threatened go extinct, the ERT rises to 2.9 Myr for bats and 23 Myr for non-volant mammals. Our results suggest that an extinction wave with deep evolutionary impact is imminent on Madagascar unless immediate conservation actions are taken.

Evolution has traditionally been a historical and descriptive science and predicting future evolutionary processes has long been considered impossible. However, evolutionary predictions are increasingly being developed and used in medicine, agriculture, biotechnology and conservation biology. Evolutionary predictions may be used for different purposes, such as to prepare for the future, to try and change the course of evolution or to determine how well we understand evolutionary processes. Similarly, the exact aspect of the evolved population that we want to predict may also differ, for example we could try to predict which genotype will dominate, the fitness of the population, or the extinction probability of a population. In addition, there are many uses of evolutionary predictions that may not always be recognized as such. The main goal of this review is to increase awareness of methods and data that are used to make these predictions in different research fields by showing the breadth of situations in which evolutionary predictions are made. We describe how diverse evolutionary predictions share a common structure described by the predictive scope, time scale and precision. Then, by using examples ranging from SARS-CoV2 and influenza to CRISPR-based gene drives and sustainable product formation in biotechnology, we discuss the methods for predicting evolution, the factors that affect predictability, and how predictions can be used to prevent evolution in undesirable directions or to promote beneficial evolution (i.e. evolutionary control). We hope that this review will stimulate collaboration between fields by creating a common language for evolutionary predictions.

Through the scope of this dissertation, I discuss the implications of diversity-dependent diversification, both as a phenomenological and a mechanistic model. Each of the following research chapters address an aspect of diversity-dependent diversification, in turn tackling its detectability in molecular phylogenies (Chapter 2), modelling the ecological processes that are hypothesized to lead to it (Chapter 3), and challenging a central assumption of the model and exploring how it impacts inference (Chapter 4). Finally, I summarise the findings of these three chapters and discuss their implications for the field of macroevolution (Chapter 5), particularly in regard to recent developments that arose during the course of the PhD.In Chapter 2, I focus on characterizing differences between diversity-dependence and time-dependence and develop a method to reliably infer which better explains the distribution of branches in molecular phylogenies.In Chapter 3, I depart from the phenomenological view and study an individual-based model, where trait-mediated interactions between organisms and their environment drive an adaptive radiation in a finite ecological niche space. As the radiation proceeds, niche space fills up and speciation becomes much less frequent, a process that is in line with the ecological interpretation of diversity-dependence. In Chapter 4, I extend the individual-based model used through Chapter 2 to consider the case of multiple clades evolving in a common niche space. The ecological scenario then approximates diversification on islands. Through these approaches, I hope to bring a better understanding of this major diversification process and more generally, how ecological dynamics influence macroevolution.

Elevated CO2 concentrations (eCO2) have been widely observed to stimulate microbial growth. However, the effect of eCO2 on soil microbial biomass may depend on several factors and their interactions, such as the increase in atmospheric CO2 levels, experimental duration and mean annual precipitation (MAP). We conducted a global meta-analysis from 62 studies that included the responses of soil microbial biomass to eCO2. We found a significant positive eCO2 effect on the bacterial biomass (+9.1 %), fungi (+11 %), arbuscular mycorrhizal fungi (AMF) (+10.2 %) and actinomycetes (ACT) (+16.4 %). The positive effects were mainly observed in studies with low eCO2 levels (≤200 ppm) rather than high levels of eCO2 (>200 ppm), which could be attributable to soil N limitation. It was also found that eCO2 had a significant positive effect on soil microbial biomass in the short term (≤3 y) and under a high MAP (>800 mm). Importantly, we revealed interactive effects between the eCO2 levels, experimental duration on soil microbial biomass. With an increase in eCO2, the total microbial biomass (TMB), bacterial biomass and fungal biomass decreased over the long term (>3 y). These findings indicate the need to incorporate interactions between eCO2 and environmental factors into ecosystem models, to predict future global climate change effects more accurately and their impact on ecosystem functions.

AimBiodiversity on islands is influenced by geophysical processes and sea-level fluctuations. Oceanic islands (never connected to a landmass) are initially vacant with diversity accumulating via colonisation and speciation, and then declining as islands shrink. Continental islands have species upon disconnection from the mainland and may have transient land-bridge connections. Theoretical predictions for the effects of these geophysical processes on rates of colonisation, speciation, and extinction have been proposed. However, paleogeographic reconstructions are currently unavailable for most islands, and phylogenetic models overlook island ontogeny, sea-level changes, or past landmass connections. We analyse to what extent ignoring geodynamics in the inference model affects model predictions when confronted with data simulated with geodynamics.LocationSimulations of oceanic and continental islands.TaxaSimulated lineages.MethodsWe extend the island biogeography simulation model DAISIE to include: (i) area-dependent rates of colonisation and diversification associated with island ontogeny and sea-level fluctuations, (ii) continental islands with biota present upon separation from the mainland, and (iii) shifts in colonisation to mimic temporary land-bridges. We quantify the error of ignoring geodynamic processes by applying DAISIE's inference method to geodynamic simulations.ResultsRobustness of the model to dynamic island area is generally high for oceanic islands and for continental islands that have been separated for a long time, suggesting that it is possible to obtain reliable results when ignoring geodynamics. However, for continental islands that have been recently or frequently connected, robustness of the model is low.Main conclusionsUnder many island biogeographic geodynamic scenarios (oceanic islands and ancient continental fragments) a simple phylogenetic model ignoring geodynamics is empirically applicable and informative. However, recent connection to the continent cannot be ignored, requiring new model development. Our results show that for oceanic islands, reliable insights can be obtained from phylogenetic data in the absence of paleogeographic reconstructions of island area.

Phenotypic plasticity allows organisms to rapidly adjust to environmental changes. Cichlid fish inhabit a wide range of light environments and show a large diversity in visual system properties, which makes them a good model system to address the role of phenotypic plasticity in visual adaptation. Cichlid retinal cone pigments consist of opsin proteins bound to Vitamin A1or A2-derived chromophores. Plasticity in expression has been shown for cichlidopsingenes, but less is known about the contribution ofcyp27c1,the enzyme that converts Vitamin A1into A2,. Here, we studied bothopsinandcyp27c1expression patterns for three closely related cichlid species from different visual habitats in Lake Victoria, across different light treatments. We found differences incyp27c1as well as inopsinexpression patterns between the three species. Experimental light treatments affected the developmental trajectory ofcyp27c1expression in one species andopsinexpression in all three species. Within each species, we found large individual variation incyp27c1expression levels and no consistent association withopsinexpression levels. These results indicate that visual system plasticity of even closely related species can be differentially mediated byopsinandcyp27c1expression, possibly associated with species differences in visual niche.

Sociability – an individual’s propensity to engage in group activities – is a conserved trait throughout most of life. Sociability can be considered as a personality type in humans when showing correlated sociability measures across different assays. Our knowledge of the mechanisms that drive sociability and explain its inter-individual variation is still limited. To enhance our mechanistic understanding, the genetically tractable Drosophila melanogaster is increasingly being used as a model for research on social behaviour. High and low sociability phenotypes, indicative of a variation of sociability levels among the population have been documented in this species. However, sociability traits have been measured through unidimensional assays, which do not allow us to assess whether sociability is a personality type in fruit flies. Here, we present a multidimensional approach to assess sociability, using a combination of three behavioural assays that each captures a different functional feature of social interactions in D.melanogaster. We applied our approach to the Drosophila melanogaster Genetic Reference Panel (DGRP) lines and revealed continuous variation in the strength of response to others. We found that sociability levels varied between genetically distinct lines, indicative of a genetic component of sociability.The three sociability traits were, however, not correlated, making it questionable whether sociability can be considered a personality type in D. melanogaster.

Phenotypic plasticity allows individuals to cope with different environmental conditions without the need for genetic adaptation. Consequently, plasticity affects the nature and strength of selection on traits. Plasticity enables individuals to experience novel selection pressures, for example through migration, possibly leading to genetic adaptation. At the same time, plasticity may shield the genotype from selection, impeding genetic adaptation. Plasticity, therefore, can have opposing effects on evolutionary change and population divergence.The visual system of cichlid fish is a suitable model trait to study the relationship between plasticity and evolutionary change, because of the high species richness and the variation among species in visual habitat. Furthermore, plasticity in the expression of genes involved in the cichlid’ visual system is well established. Here, we test whether visual plasticity is correlated to the degree of ecological specialisation and clade species richness. We quantify plasticity in the expression of these genes in species from species-poor and species-rich clades, inhabiting different visual habitats in nature, by exposing individuals to different light conditions and determining light-induced variation in gene expression. Preliminary results indicate that expression indeed differs among light treatments, in multiple species. We expect our study to provide a better understanding of the impact of phenotypic plasticity on divergent evolution.

The predictability of evolution is expected to depend on the relative contribution of deterministic and stochastic processes. This ratio is modulated by effective population size. Smaller effective populations harbor less genetic diversity and stochastic processes are generally expected to play a larger role, leading to less repeatable evolutionary trajectories. Empirical insight into the relationship between effective population size and repeatability is limited and focused mostly on asexual organisms. Here, we tested whether fitness evolution was less repeatable after a population bottleneck in obligately outcrossing populations of Caenorhabditis elegans. Replicated populations founded by 500, 50, or five individuals (no/moderate/strong bottleneck) were exposed to a novel environment with a different bacterial prey. As a proxy for fitness, population size was measured after one week of growth before and after 15 weeks of evolution. Surprisingly, we found no significant differences among treatments in their fitness evolution. Even though the strong bottleneck reduced the relative contribution of selection to fitness variation, this did not translate to a significant reduction in the repeatability of fitness evolution. Thus, although a bottleneck reduced the contribution of deterministic processes, we conclude that the predictability of evolution may not universally depend on effective population size, especially in sexual organisms. ispartof: EVOLUTION vol:76 issue:8 pages:1896-1904 ispartof: location:United States status: published

Compared to other regions, the drivers of diversification in Africa are poorly understood. We studied a radiation of insects with over 100 species occurring in a wide range of habitats across the Afrotropics to investigate the fundamental evolutionary processes and geological events that generate and maintain patterns of species richness on the continent. By investigating the evolutionary history of Bicyclus butterflies within a phylogenetic framework, we inferred the group’s origin at the Oligo-Miocene boundary from ancestors in the Congolian rainforests of central Africa. Abrupt climatic fluctuations during the Miocene (ca. 19–17 Ma) likely fragmented ancestral populations, resulting in at least eight early-divergent lineages. Only one of these lineages appears to have diversified during the drastic climate and biome changes of the early Miocene, radiating into the largest group of extant species. The other seven lineages diversified in forest ecosystems during the late Miocene and Pleistocene when climatic conditions were more favorable—warmer and wetter. Our results suggest changing Neogene climate, uplift of eastern African orogens, and biotic interactions have had different effects on the various subclades of Bicyclus, producing one of the most spectacular butterfly radiations in Africa. [Afrotropics; biodiversity; biome; biotic interactions; Court Jester; extinction; grasslands; paleoclimates; Red Queen; refugia forests; dependent-diversification; speciation.]

In plant communities, genotypic diversity can impact the plant community structure and ecosystem functions, but related research has focused on native plants. Therefore, whether genotypic diversity affects the growth of invasive plants and then changes the wetland microecosystem remains unresolved. In this study, six different genotypes of Hydrocotyle vulgaris, a common invasive plant in China, were selected to construct populations with three different genotypic diversity levels (one, three, and six genotype combinations, respectively) to explore the effects of different genotypic diversity levels on the growth and physiological traits of H. vulgaris, and soil nutrients and greenhouse gas emissions of the wetland microecosystem under flooding conditions. We found that genotypic diversity improved the leaf area, root to shoot ratio and photosynthetic physiological traits of H. vulgaris, especially under flooding. Moreover, genotypic diversity increased soil organic matter (SOM) contents in the wetland microecosystem, while it reduced the cumulative nitrous oxide emissions under flooding conditions. Overall, genotype diversity improved photosynthetic traits of H. vulgaris, further increased SOM, and reduced the N2O emissions of the wetland microecosystem. The results of this study can provide a theoretical basis for exploring how genotypic diversity levels affect the invasiveness of invasive plants and ecosystems in wetland microecosystems.

The Black-tailed Godwit Limosa limosa is a globally Near Threatened species but a common winter visitor to Bangladesh. Although the total wintering population size and trend are unknown, we suspect it is declining due to habitat degradation. Nijhum Dweep National Park is one of the most important sites for Black-tailed Godwits in Bangladesh. Here we report on the site use of Black-tailed Godwits in this national park and adjacent Char Birbira. From October to March 2016–2017 to 2019–2020, we performed 17 winter counts. High-tide roosts were counted from vantage points in these tidal areas, whereas foraging activities were observed from boats during low tide. Black-tailed Godwits were always present, with counts ranging from 735 in January 2020 to 8,269 in December 2017 with a mean of 3,304. The uncertainty of these counts and population estimates for this area in general suggest that better assessment methods, such as simultaneous high-tide counts undertaken at the same time each year, are needed. Our study area met the Ramsar 1% threshold population criterion for the species for 13 of the 17 counts, demonstrating the international importance of this area for Black-tailed Godwits. A local decline of >80% from 9,000 to 1,707 birds over the last decade was apparent on Damar Char West. Over the decades, the landscape of Damar Char has changed, with increased numbers of households, more land converted to agricultural fields, and increased fishing effort. These changes call for better assessments of bird movements and disturbance and more effective conservation actions to help birds and people coexist. We suggest that there should be a monitoring and protection scheme in the Nijhum Dweep management plan that focuses on waterbirds, and restricts and regulates access to Damar Char West, East and Char Birbira. An urgent attempt to create awareness among the main stakeholders, fishers and crab hunters, to provide context and engage them in conservation action, should be a priority.

Understanding the mechanisms that generate the outstanding biological diversity on our planet has been extensively studied. However, to this date many questions remain unresolved. A fundamental process that produces biodiversity is divergent adaptation: here populations diversify by adapting to different environmental conditions. In this project, I investigated the role of the sensory system in this process, as sensory perception is critical for survival and reproduction: How do sensory systems adapt to local environments and (how) does individual flexibility contribute to this process? The fish visual system provides an excellent opportunity to study these questions as it shows extensive variation among species/populations. Fish inhabit different visual environments, as a result of wavelength-dependent light attenuation in water. There are strong indications that adaptation of the visual pigments in fish eyes plays a role in the origin and persistence of species. In this thesis I focused on cichlid fish, one of the most species-rich vertebrate families. At the level of visual pigment molecular composition, I showed that closely related species deal in different ways with variation in light conditions and differ in their plastic response to experimental light treatments. Despite these differences, fish did not go where they saw best in a behavioural choice experiment. Instead, they had a general preference for blue light. Finally, in a comparative analysis I found no evidence that diversification rates depend on the visual environment of a lineage. Together, my findings highlight that vision rapidly diverges between species/populations, impacts behaviour and is also influenced by individual flexibility.

Few biological groups have a well-documented fossil history, detailed trait datasets, reliable distribution maps, and are distributed on a global scale. The Canidae family is one of them, which allows us to tackle several topics related to evolutionary processes and species’ relationship with their environment. Here, I bring a broader view on distinct spatial patterns of Canidae, elucidating many points that are not yet very well understood about this group. By assembling distinct datasets (e.g., phylogenetic trees, paleontological data, species distribution maps, and environmental variables) together with several methods to extract information from these data, I demonstrate which were the main continental dispersal events over the last 13 million years in Canidae, and how these events shaped the diversification patterns of this clade leading to explosive diversification right after the colonization of new areas. I also show that environmental factors are more important than species interactions to explain how Canidae assemblages are structured spatially at the present. Moreover, I demonstrate the drastic climatic scenario for the majority of canids around the world during the next 54 years. In this thesis, I also test if diversification rates of canids are associated with distinct areas around the planet. The results show that when fossils species are incorporated in the analyses distinct diversification patterns are not related to geographic areas.

Group-living facilitates cooperation between individuals, but also creates competition for limited resources. Individuals should thus modulate their reproductive output in response to the presence of others. However, mechanisms that lead to such social context-dependent modulation of reproduction are poorly understood. In the fruit fly Drosophila melanogaster, females actively attract conspecifics to lay eggs on the same resources, generating groups in which individuals may cooperate or compete. The genetic tractability of this species gave me an opportunity to dissect the mechanisms by which females adjust their behaviour and physiology to their social environment. I discovered social facilitation of oogenesis and egg-laying in Drosophila melanogaster and described the neuro-hormonal mechanisms underlying this modulation. I demonstrated that social environment affects ovarian activity of females in a density-dependent manner. I showed that these responses to the presence of others are mediated by vision through the motion detection pathway and are the result of the stimulation of the juvenile hormone pathway. While social modulation of reproduction is considered a sign of sociality and is mostly expressed in social hymenopterans, my findings thus demonstrate that such phenomenon can already be found in rather solitary species such as D. melanogaster, making the concept of solitary vs social species a bit artificial. I moreover proposed a new approach to explore the variation in sociability among D. melanogaster through the quantification of multiple sociability traits. I found significant variation between the flies in the strength of responses to others, demonstrating the existence of a sociability spectrum in this species.

Herbivore diets are often generalistic, and communities of herbivores tend to share much of their diets. In the tropical lowlands of Malaysian Borneo, tens of different noncarnivorous land snail species are able to coexist in communities on limestone outcrops. We tried to answer the question whether diet differentiation plays a role in their coexistence. We show, with a large metabarcoding study of the plant diet from gut contents of 658 individual snails (from 26 species, with a focus on three of the most common species in the region), that the different snail species indeed share much of their plant diet, but that mean diet richness varies strongly among species (up to 15.3×). These differences are mostly explained by snail size, with larger snails having wider diets. Furthermore, phylogenetic analyses of the plant diet by individual snails showed signs of clustering in c. 28% of the individuals, possibly suggesting phylogenetic specialization, although such clustering was weak when diets were considered by species. We discuss how observed trends in diet richness and diet clustering could also be explained by random feeding, with larger species simply eating more or less specifically, and by other, noncompetitive interactions, such as snails avoiding desiccation. Our study shows how to efficiently put the power of metabarcoding to work in unravelling the complex community processes commonly encountered in tropical ecosystems and is thus of substantial relevance to both community ecologists and conservationists.