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How climate affects species distributions is a longstanding question receiving renewed interest owing to the need to predict the impacts of global warming on biodiversity. Is climate change forcing species to live near their critical thermal limits? Are these limits likely to change through natural selection? These and other important questions can be addressed with models relating geographical distributions of species with climate data, but inferences made with these models are highly contingent on non-climatic factors such as biotic interactions. Improved understanding of climate change effects on species will require extensive analysis of thermal physiological traits, but such data are scarce and scattered. To overcome current limitations, we created the GlobTherm database. The database contains experimentally derived species’ thermal tolerance data currently comprising over 2,000 species of terrestrial, freshwater, intertidal and marine multicellular algae, pl ants, fungi, and animals. The GlobTherm database will be maintained and curated by iDiv with the aim of expanding it, and enable further investigations on the effects of climate on the distribution of life on Earth.

How climate affects species distributions is a longstanding question receiving renewed interest owing to the need to predict the impacts of global warming on biodiversity. Is climate change forcing species to live near their critical thermal limits? Are these limits likely to change through natural selection? These and other important questions can be addressed with models relating geographical distributions of species with climate data, but inferences made with these models are highly contingent on non-climatic factors such as biotic interactions. Improved understanding of climate change effects on species will require extensive analysis of thermal physiological traits, but such data are both scarce and scattered. To overcome current limitations, we created the GlobTherm database. The database contains experimentally derived species’ thermal tolerance data currently comprising over 2,000 species of terrestrial, freshwater, intertidal and marine multicellular algae, plants, fungi, and animals. The GlobTherm database will be maintained and curated by iDiv with the aim to keep expanding it, and enable further investigations on the effects of climate on the distribution of life on Earth.

How climate affects species distributions is a longstanding question receiving renewed interest owing to the need to predict the impacts of global warming on biodiversity. Is climate change forcing species to live near their critical thermal limits? Are these limits likely to change through natural selection? These and other important questions can be addressed with models relating geographical distributions of species with climate data, but inferences made with these models are highly contingent on non-climatic factors such as biotic interactions. Improved understanding of climate change effects on species will require extensive analysis of thermal physiological traits, but such data are both scarce and scattered. To overcome current limitations, we created the GlobTherm database. The database contains experimentally derived species’ thermal tolerance data currently comprising over 2,000 species of terrestrial, freshwater, intertidal and marine multicellular algae, plants, fungi, and animals. The GlobTherm database will be maintained and curated by iDiv with the aim to keep expanding it, and enable further investigations on the effects of climate on the distribution of life on Earth.

Identifying the factors generating ecomorphological diversity within species can provide a window into the nascent stages of ecological radiation. Sexual dimorphism is an obvious axis of intraspecific morphological diversity that could affect how environmental variation leads to ecological divergence among populations. In this paper we test for sex‐specific responses in how environmental variation generates phenotypic diversity within species, using the generalist lizard Gallotia galloti on Tenerife (Canary Islands). We evaluate two hypotheses: the first proposes that different environments have different phenotypic optima, leading to shifts in the positions of populations in morphospace between environments; the second posits that the strength of trait‐filtering differs between environments, predicting changes in the volume of morphospace occupied by populations in different environments. We found that intraspecific morphological diversity, provided it is adaptive, arises from both shifts in populations’ position in morphospace and differences in the strength of environmental filtering among environments, especially at high elevations. However, effects were found only in males; morphological diversity of females responded little to environmental variation. These results within G. galloti suggest natural selection is not the sole source of phenotypic diversity across environments, but rather that variation in the strength of, or response to, sexual selection may play an important role in generating morphological diversity in environmentally diverse settings. More generally, disparities in trait–environment relationships among males and females also suggest that ignoring sex differences in studies of trait dispersion and clustering may produce misleading inferences.

The opportunity to reflect broadly on the accomplishments, prospects, and reach of a field may present itself relatively infrequently. Each biennial meeting of the International Biogeography Society showcases ideas solicited and developed largely during the preceding year, by individuals or teams from across the breadth of the discipline. Here, we highlight challenges, developments, and opportunities in biogeography that were summarized at or emerge from that biennial synthesis. We note the realized and potential impact of rapid data accumulation in several fields, a Renaissance for inter-disciplinary research, the importance of recognizing the evolution-ecology continuum across spatial and temporal scales and at different taxonomic, phylogenetic and functional levels, and re-exploration of classical assumptions and hypotheses using new tools. However, advances are taxonomically and geographically biased, key theoretical frameworks await development of tools for handling, or strategies for simplifying, the biological complexity seen in empirical systems. Current threats to biodiversity require unprecedented integration of knowledge and development of predictive capacity that may enable biogeography to unite its descriptive and hypothetico-deductive arms and establish a greater role within and outside academia.

Understanding the climatic and historical factors shaping species richness is a major goal of ecology and biogeography. Consensus on how climate affects species richness is still lacking, but four potential and non-exclusive explanations have emerged: water-energy, where diversity is determined by precipitation and/or temperature; seasonality, where diversity is determined by seasonal variation in climate; heterogeneity, where diversity is determined by spatial variability in climate; and historical climatic stability, where diversity is determined by changes in climate through evolutionary time. Climate–richness relationships are also mediated by historical processes such as phylogenetic niche conservatism and lineage diversification across regions. We evaluated the effect of climate on species richness gradients of Anolis lizards and tested the role of phylogenetic niche conservatism (PNC) and regional diversification (RD) in the origin and maintenance of climate-richness relationships. Climate had a strong non-stationary relationship with species richness with strong shared effects among several climate axes. Regional differences in climate–richness relationships suggest different assembly processes between regions. However, we did not find evidence for a role of evolutionary factors such as PNC or RD underlying these relationships. We suggest that evolutionary processes affecting climate-richness relationships in Anolis likely were obscured by high dispersal rates between regions.

Aim The aim of this study was to test the link between climatic niche dynamics and species diversification in Anolis on islands and on the mainland. We tested the hypotheses that lineages in warmer climates and with narrow climate niches diversified more than lineages in cold climates and with broad climate niches. We also tested the hypothesis that species-rich clades exhibit greater niche diversity than species-poor clades. Location Neotropics. Methods We collated occurrence records for 328 Anolis species to estimate niche breadth, niche position and occupied niche space (as a proxy for niche diversity). We compared niche breadth between insular and mainland Anolis species and among Anolis clades, controlling for the potential confounding effect of range size. Using two approaches (clade-based and QuaSSE) we explored the association between niche metrics and diversification rates in Anolis lizards. Results We found that Caribbean Anolis had a narrower niche breadth and niche space occupation compared to mainland anoles after controlling for range size differences. There was a significant association between niche traits (mean niche position and niche breadth) and diversification in anoles. Anole lineages with narrow niche breadths and that occupy warmer areas exhibited higher speciation rates than those with broader niche breadths and that occupy cold areas. Similarly, clades with higher total diversification exhibit more niche diversity than clades with lower total diversification. Main conclusions Climatic niche attributes play a role in anole diversification with some differences between mainland and insular anole lineages. Climatic niche differences between regions and clades likely are related to differences in niche evolutionary rates. This also suggests that climate plays a strong role in shaping species richness between and within mainland and islands.

Aims To examine species richness patterns in Papua New Guinea’s terrestrial vertebrates and test for geographical congruence between the four classes, and between lizard and snake subgroups. To assess the environmental correlates of Papua New Guinean terrestrial-vertebrate richness, and contrast effects of varying analytical resolution and correction for spatial autocorrelation. We predict congruence in the bird, mammal and to a lesser extent amphibian richness, with weak congruence or incongruence between reptiles and the other taxonomic groups. We further predict these patterns will stem from relative or in the case of reptiles dissimilar, correlative trends with environmental predictors such as elevation and temperature. Location Papua New Guinea. Methods Having created and updated distribution maps for reptiles, we compare them with known ranges of amphibians, birds and mammals and generate species richness grids at quarter-, half- and one- degree spatial resolutions. We examine congruence in species richness between vertebrate groups and between reptile subgroups. We employed spreading-dye models to simulate species richness according to eight environmental predictors and one random model. We accounted for spatial autocorrelation in all analyses. Results Papua New Guinean amphibian, bird and mammal species richness are spatially congruent, a trend which strengthens with decreasing spatial resolution. Reptiles and the lizard and snake subgroups reveal remarkably different spatial-richness trends. Elevational predictors, particularly elevational range at coarse resolutions, provide the strongest correlates of species richness. Terrestrial-vertebrate richness increases with elevation, whereas reptile richness decreases. Main conclusions Congruent species richness gradients in Papua New Guinea are observed in most terrestrial vertebrates, except reptiles. Topographic heterogeneity and associated climatic clines promote diversity in most terrestrial vertebrates but

Identifying the factors generating ecomorphological diversity within species can provide a window into the nascent stages of ecological radiation. Sexual dimorphism is an obvious axis of intraspecific morphological diversity that could affect how environmental variation leads to ecological divergence among populations. In this paper we test for sex-specific responses in how environmental variation generates phenotypic diversity within species, using the generalist lizard Gallotia galloti on Tenerife (Canary Islands). We evaluate two hypotheses: the first proposes that different environments have different phenotypic optima, leading to shifts in the positions of populations in morphospace between environments; the second posits that the strength of trait-filtering differs between environments, predicting changes in the volume of morphospace occupied by populations in different environments. We found that intraspecific morphological diversity, provided it is adaptive, arises from both shifts in populations’ position in morphospace and differences in the strength of environmental filtering among environments, especially at high elevations. However, effects were found only in males; morphological diversity of females responded little to environmental variation. These results within G. galloti suggest natural selection is not the sole source of phenotypic diversity across environments, but rather that variation in the strength of, or response to, sexual selection may play an important role in generating morphological diversity in environmentally diverse settings. More generally, disparities in trait–environment relationships among males and females also suggest that ignoring sex differences in studies of trait dispersion and clustering may produce misleading inferences.

Bergmann’s rule—the tendency for body size to increase in colder environments—remains controversial today, despite 150 years of research. Considerable debate has revolved around whether the rule applies within or among species. However, this debate has generally not considered that clade-level relationships are caused by both intra- and interspecific effects. In this article, we implement a novel approach that allows for the separation of intra- and interspecific components of trait-environment relationships.We apply this approach to body size clines in two Caribbean clades of Anolis lizards and discover that their similar body size gradients are constructed in very different ways. We find inverse Bergmann’s clines—high elevation lizards are smaller bodied—for both the cybotes clade on Hispaniola and the sagrei clade on Cuba. However, on Hispaniola, the inverse cline is driven by interspecific differences, whereas intraspecific variation is responsible for the inverse cline on Cuba. Our results suggest that similar body size clines can be constructed through differing evolutionary and ecological processes, namely, through local adaptation or phenotypic plasticity (intraspecific clines) and/or size-ordered spatial sorting (interspecific clines). We propose that our approach can help integrate a divided research program by focusing on how the combined effects of intra- and interspecific processes can enhance or erode clade-level relationships at large biogeographic scales.

Understanding how quickly physiological traits evolve is a topic of great interest, particularly in the context of how organisms can adapt in response to climate warming. Adjustment to novel thermal habitats may occur either through behavioural adjustments, physiological adaptation, or both. Here we test whether rates of evolution differ among physiological traits in the cybotoids, a clade of tropical Anolis lizards distributed in markedly different thermal environments on the Caribbean island of Hispaniola. We find that cold tolerance evolves considerably faster than heat tolerance, a difference that results because behavioural thermoregulation more effectively shields these organisms from selection on upper than lower temperature tolerances. Specifically, because lizards in very different environments behaviourally thermoregulate during the day to similar body temperatures, divergent selection on body temperature and heat tolerance is precluded, whereas night-time temperatures can only be partially buffered by behaviour, thereby exposing organisms to selection on cold tolerance. We discuss how exposure to selection on physiology influences divergence among tropical organisms and its implications for adaptive evolutionary response to climate warming.

Many oceanic islands are notable for their high endemism, suggesting that islands may promote unique assembly processes. However, mainland assemblages sometimes harbour comparable levels of endemism, suggesting that island biotas may not be as unique as is often assumed. Here, we test the uniqueness of island biotic assembly by comparing the rate of species turnover among islands and the mainland, after accounting for distance decay and environmental gradients. We modelled species turnover as a function of geographical and environmental distance for mainland (M–M) communities of Anolis lizards and Terrarana frogs, two clades that have diversified extensively on Caribbean islands and the mainland Neotropics. We compared mainland–island (M–I) and island–island (I–I) species turnover with predictions of the M–M model. If island assembly is not unique, then the M–M model should successfully predict M–I and I–I turnover, given geographical and environmental distance. We found that M–I turnover and, to a lesser extent, I–I turnover were significantly higher than predicted for both clades. Thus, in the first quantitative comparison of mainland–island species turnover, we confirm the long-held but untested assumption that island assemblages accumulate biodiversity differently than their mainland counterparts.