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The immense concentrations of vertebrate species in tropical mountains remain a prominent but unexplained pattern in biogeography. A long-standing hypothesis suggests that montane biodiversity hotspots result from endemic species aggregating within ecologically stable localities. Here, the persistence of ancient lineages coincides with frequent speciation events, making such areas both ‘cradles’ (where new species arise) and ‘museums’ (where old species survive). Although this hypothesis refers to processes operating at the scale of valleys, it remains supported primarily by patterns generated from coarse-scale distribution data. Using high-resolution occurrence and phylogenetic data on Andean hummingbirds, we find that old and young endemic species are not spatially aggregated. The young endemic species tend to have non-overlapping distributions scattered along the Andean treeline, a long and narrow habitat where populations easily become fragmented. By contrast, the old endemic species have more aggregated distributions, but mainly within pockets of cloud forests at lower elevations than the young endemic species. These findings contradict the premise that biogeographical cradles and museums should overlap in valley systems where pockets of stable climate persist through periods of climate change. Instead, Andean biodiversity hotspots may derive from large-scale fluctuating climate complexity in conjunction with local-scale variability in available area and habitat connectivity.

The tea family (Theaceae) has a highly unusual amphi-Pacific disjunct distribution: most extant species in the family are restricted to subtropical evergreen broadleaf forests in East Asia, while a handful of species occur exclusively in the subtropical and tropical Americas. Here, we used an approach that integrates the rich fossil evidence of this group with phylogenies in biogeographic analysis to study the processes behind this distribution pattern. We first combined genome-skimming sequencing with existing molecular data to build a robust species-level phylogeny for c.130 Theaceae species, resolving most important unclarified relationships. We then developed an empirical Bayesian method to incorporate distribution evidence from fossil specimens into historical biogeographic analyses and used this method to account for the spatiotemporal history of Theaceae fossils. We compared our method with an alternative Bayesian approach and show that it provides consistent results while significantly reduces computational demands which allows analyses of much larger data sets. Our analyses revealed a circumboreal distribution of the family from the early Cenozoic to the Miocene and inferred repeated expansions and retractions of the modeled distribution in the Northern Hemisphere, suggesting that the current Theaceae distribution could be the remnant of a larger continuous distribution associated with the boreotropical forest that has been hypothesized to occupy most of the northern latitudes in the early Cenozoic. These results contradict with studies that only considered current species distributions and showcase the necessity of integrating fossil and molecular data in phylogeny-based parametric biogeographic models to improve the reliability of inferred biogeographical events. [Biogeography; genome skimming; phylogenomics; plastid genome; Theaceae.]

Aim Adaptive radiation, in which successful lineages proliferate by exploiting untapped niche space, provides a popular but potentially misleading characterization of evolution on oceanic islands. Here we analyse the respective roles of members of in situ diversified vs. non-diversified lineages in shaping the main ecosystems of an archipelago to explore the relationship between evolutionary and ecological ‘success’. Location Canary Islands. Taxon Vascular plants. Methods We quantified the abundance/rarity of the native flora according to the geographical range (number of islands where present and geographical extent of the range), habitat breadth (climatic niche) and local abundance (cover) using species distribution data based on 500 × 500 m grid cells and 2000 vegetation inventories located all over the archipelago. Results Species of diversified lineages have significantly smaller geographic ranges, narrower climatic niches and lower local abundances than those of non-diversified lineages. Species rarity increased with the degree of diversification. The diversified Canarian flora is mainly comprised by shrubs. At both archipelagic and island level, the four core ecosystems (Euphorbia scrub, thermophilous woodlands, laurel forest and pine forest) were dominated by non-diversified lineages species, with diversified lineages species providing

The causes of continental patterns in species richness continue to spur heated discussion. Hypotheses based on ambient energy have dominated the debate, but are increasingly being challenged by hypotheses that model richness as the overlap of species ranges, ultimately controlled by continental range dynamics of individual species. At the heart of this controversy lies the question of whether species richness of individual grid cells is controlled by local factors, or reflects larger-scale spatial patterns in the turnover of species’ ranges. Here, we develop a new approach based on assemblage dispersion fields, formed by overlaying the geographic ranges of all species co-occurring in a grid cell. We created dispersion fields for all tetrapods of South America, and characterized the orientation and shape of dispersion fields as a vector field. The resulting maps demonstrate the existence of macro-structures in the turnover of biotic similarity at continental scale that are congruent among vertebrate classes. These structures underline the importance of continental-scale processes for species richness in individual assemblages., Ecologists continue to debate whether local species assemblages result from habitat filtering or from turnover among the regional species pool. Here the authors develop a “dispersion field” method to mapping species range overlaps, showing that regional turnover processes are key to local assembly.

Aim: The General Dynamic Model (GDM) links island biogeographical processes to island geological history. A key premise of the GDM implies that environmental factors shaping the ecology and evolution of biota on oceanic islands follow a hump-shaped trend over the island's life span and drive dynamics in carrying capacity, species diversity and endemism. An important component of the GDM is environmental heterogeneity (EH), but its effects on insular diversity remain poorly understood. Here, we first quantified EH, tested whether EH follows the expected hump-shaped trend along island ontogeny and evaluated how EH relates to plant diversity. Location: 135 oceanic islands of volcanic origin. Taxon: Vascular plants. Methods: We calculated 20 EH metrics focusing on topographic and climatic components of EH, and compared whole-island metrics (e.g. range) and moving-window metrics (e.g. roughness). Using linear mixed-effects models, we evaluated the trends of EH with island age and the EH–plant diversity relationship expected based on the GDM. Results: Our analysis revealed some EH components to be collinear, for example, elevation and temperature heterogeneity but also that EH metrics capture different aspects of EH, for example, climatic gradients versus climatic complexity. EH generally followed a hump-shaped trend with island age, peaking early during island ontogeny. Among the EH components, climatic heterogeneity had the strongest effect on plant species richness and elevational heterogeneity on endemism. Lastly, including EH metrics in GDMs (traditionally, only island age and area were included) improved their predictive power. Main conclusions: The EH metrics compared here captured various attributes of the environment that influence insular plant diversity. In line with the GDM, our results strongly support a hump-shaped relationship between EH and island age, suggesting that islands become highly heterogeneous early in their ontogeny. Finally, the contribution of EH to GDM-based models of species richness and endemism suggests that EH is a main driver of the diversity of oceanic island biotas. Refereed/Peer-reviewed

AIM: Mountains and islands are both well known for their high endemism. To explain this similarity, parallels have been drawn between the insularity of "true islands" (land surrounded by water) and the isolation of habitats within mountains (so-called "mountain islands"). However, parallels rarely go much beyond the observation that mountaintops are isolated from one another, as are true islands. Here, we challenge the analogy between mountains and true islands by re-evaluating the literature, focusing on isolation (the prime mechanism underlying species endemism by restricting gene flow) from a dynamic perspective over space and time. FRAMEWORK: We base our conceptualization of "isolation" on the arguments that no biological system is completely isolated; instead, isolation has multiple spatial and temporal dimensions relating to biological and environmental processes. We distinguish four key dimensions of isolation: (a) environmental difference from surroundings; (b) geographical distance to equivalent environment [points (a) and (b) are combined as "snapshot isolation"]; (c) continuity of isolation in space and time; and (d) total time over which isolation has been present [points (c) and (d) are combined as "isolation history"]. We evaluate the importance of each dimension in different types of mountains and true islands, demonstrating that substantial differences exist in the nature of isolation between and within each type. In particular, different types differ in their initial isolation and in the dynamic trajectories they follow, with distinct phases of varying isolation that interact with species traits over time to form present-day patterns of endemism. CONCLUSIONS: Our spatio-temporal definition of isolation suggests that the analogy between true islands and mountain islands masks important variation of isolation over long time-scales. Our understanding of endemism in isolated systems can be greatly enriched if the dynamic spatio-temporal dimensions of isolation enter models as explanatory variables and if these models account for the trajectories of the history of a system. Department of Biodiversity, Macroecology & Biogeography at University of Gottingen; The Netherlands Organization for Scientific Research (NWO, no. 2012/13248/ALW to H. Hooghiemstra); European Research Council (ERC) Advanced Grant (no. 741413, Humans on Planet Earth (HOPE); Marie Sklodowska-Curie grant agreement (no. 707968); Danish National Research Foundation for support of the Center for Macroecology, Evolution and Climate (no. DNRF96); Austrian Science Foundation (Fonds zur Forderung der wissenschaftlichen Forschung, FWF, no. I 3757-B29); Portuguese National Funds, through Fundação para a Ciência e a Tecnologia (FCT), within the project UID/BIA/00329/2013 and the research Fellowship PD/BD/114380/2016; Horizon 2020 research and innovation programme (no. 641762). info:eu-repo/semantics/publishedVersion

A desirable goal of nature management is to re-establish self-sustaining ecosystems that ensure the persistence of natural habitats and species without requiring active management. Such self-sustainability relies on functional species interactions; yet, species interactions are often overlooked in the conservation literature, and when designing species-specific management efforts. Some interactions may not be restored under general management (e.g. land protection), and may require additional specific management interventions. Interventions targeting these specific interactions fall in a gap between general and species-specific management, effectively bridging community- and population-level approaches to conservation management. We propose that managers should explicitly identify cases where active management of specific interaction partners is required to achieve population self-sustainability. In addition, they should ensure that general management interventions do not inadvertently conflict with naturally occurring interactions, potentially thwarting conservation targets. Interaction functionality may be restored by relying on native species and by identifying the spatial context in which interactions are most likely to re-establish, considering distributional range overlap of interaction partners, local variation in individual encounter rate or even spatial variation in the expected success rate (efficiency) of the focal interaction.

AIM: Positive relationships in compositional similarity between consumer and resource assemblages are widely known in free‐living taxa, but less is known about parasites and their hosts. We investigated whether congruent patterns of assemblage similarity across diverse taxa of hosts and parasites exist at a continental scale and quantified the relative importance of host assemblages and environmental variables in shaping these relationships. LOCATION: European freshwaters. MAJOR TAXA STUDIED: The hosts were fishes, birds and mammals. The parasites were monogeneans, trematodes and copepods. METHODS: We extracted distribution data from the Limnofauna Europaea for three aquatic parasite taxa and for three vertebrate taxa functioning as their definitive hosts across 25 biogeographical regions in Europe. First, we investigated β‐diversity congruence patterns between parasite and host assemblages, corrected for the distance between regions using partial Mantel tests. Second, we assessed the relative importance of host assemblages and environmental variables in shaping parasite β‐diversity patterns using generalized dissimilarity models (GDMs). RESULTS: Spatial community dissimilarities of regional parasite assemblages were positively correlated with those of their respective host assemblages in all five parasite–host groups studied. The GDMs highlighted the equal importance of both host assemblages and environmental variables in shaping parasite assemblages. However, the direct effect of host assemblages was relatively small compared with the effect of environmental factors mediated by host assemblages. Climatic parameters (precipitation and temperature) contributed most to the variance explained by environmental variables. MAIN CONCLUSIONS: Our analyses indicate that spatially congruent patterns of assemblage similarity exist between parasites and their hosts at a continental scale. They also suggest that this congruence is driven not only by host assemblages but also by environmental (climatic) variables, either directly or indirectly via their effects on host assemblages. Thus, environmental variables are important for mapping, forecasting and management of parasites at a geographical scale.

The archipelagos that form the transition between Asia and Australia were immortalized by Alfred Russel Wallace's observations on the connections between geography and animal distributions, which he summarized in what became the first major modern biogeographic synthesis. Wallace traveled the island region for eight years, during which he noted the marked faunal discontinuity across what has later become known as Wallace's Line. Wallace was intrigued by the bewildering diversity and distribution of life he discovered. But even today we ask ourselves how species formed within the region and why they are not evenly distributed. Biogeography, phylogeny, dispersal, biotic interactions, and abiotic factors affect the assembly of diversity. On the basis of a decade of research on the ecology, evolution, and systematics of corvoid passerine birds, we summarize what we have learned about the biogeography and assembly of island bird diversity. Corvoid passerine birds include nearly 800 species and 2,300 named taxa and thus represent a large, well-described, and globally distributed clade. Understanding the processes influencing biodiversity in this group is certain to deepen our general understanding of ecology and evolution in the context of biogeography and faunal assembly.

Reeve et al. (2016, Ecography, 39, 990-997) found that ecologically flexible endemics dominate Indo-Pacific bird communities. This negative relationship between local abundance and global range size contrasts strongly with the positive range size-abundance relationship “rule,” which would predict community dominance by globally widespread species. Theuerkauf et al. (2017, Journal of Biogeography, 44, 2161–2163) provide new data from New Caledonia which they claim invalidate our study. They find positive relationships between local abundance and local range size, which they attribute to endemic species having narrower habitat niches than globally widespread species. We reanalysed their data using global range sizes, corroborating the pattern we originally reported: negative relationships between local abundance and global range size, driven by a subset of adaptable endemic species. We stress the importance of being explicit about the scale of ecological mechanisms, and ensuring that the scale of analysis matches the scale of interpretation.

Mountain regions are unusually biodiverse, with especially rich aggregations of small-30 ranged species that form centers of endemism. Mountains play an array of important roles for Earth's biodiversity, and impact neighboring lowlands through biotic interchange, changes in regional climate, and nutrient run-off. The high biodiversity of certain mountains reflects the interplay of multiple evolutionary mechanisms: enhanced speciation rates with unique opportunities for co-existence and persistence of lineages, shaped by long-term climatic changes 35 interacting with topographically dynamic landscapes. High diversity in most tropical mountains is tightly linked to bedrock geology, notably areas comprising mafic and ultramafic lithologies—rock types rich in magnesium and poor in phosphate that present special requirements for plant physiology. Mountain biodiversity bears the signature of deep-time evolutionary and ecological processes, a history worth preserving in the face of contemporary environmental changes.

Mountains contribute disproportionately to the terrestrial biodiversity of Earth, especially in the tropics, where they host hotspots of extraordinary and puzzling richness. With about 25% of all land area, mountain regions are home to more than 85% of the world’s species of amphibians, birds, and mammals, many entirely restricted to mountains. Biodiversity varies markedly among these regions. Together with the extreme species richness of some tropical mountains, this variation has proven challenging to explain under traditional climatic hypotheses. However, the complex climatic characteristics of rugged mountain regions differ fundamentally from those of lowland regions, likely playing a key role in generating and maintaining diversity. With ongoing global changes in climate and land use, the role of mountains as refugia for biodiversity may well come under threat.

Regional variation in clade richness can be vast, reflecting differences in the dynamics of historical dispersal and diversification among lineages. Although it has been proposed that dispersal into new biogeographic regions may facilitate diversification, to date there has been limited assessment of the importance of this process in the generation, and maintenance, of broad-scale biodiversity gradients. To address this issue, we analytically derive biogeographic regions for a global radiation of passerine birds (the Corvides, c. 790 species) that are highly variable in the geographic and taxonomic distribution of species. Subsequently, we determine rates of historical dispersal between regions, the dynamics of diversification following regional colonization, and spatial variation in the distribution of species that differ in their rates of lineage diversification. The results of these analyses reveal spatiotemporal differences in the build-up of lineages across regions. The number of regions occupied and the rate of transition between regions both predict family richness well, indicating that the accumulation of high clade richness is associated with repeated expansion into new geographic areas. However, only the largest family (the Corvidae) had significantly heightened rates of both speciation and regional transition, implying that repeated regional colonization is not a general mechanism promoting lineage diversification among the Corvides.

Aim During the Late Pleistocene (c. 126–10 ka), modern humans (Homo sapiens) expanded their geographical range across Eurasia and eventually colonized the Americas. Although the routes by which they migrated have been intensively analysed, the dynamics of their realized climatic niche are still largely unknown. We assess temporal changes in the climatic niche of modern humans, the geographical distribution of their climatic niche and whether niche dynamics correlate with the magnitude of climate change and cultural advances, between 46 and 11 ka. Location Palaearctic. Methods Using the radiocarbon dated archaeological record and spatial palaeoclimatic simulations, we quantify different parameters of the realized climatic niche of modern humans (niche overlap, niche breadth and climatic marginality) between consecutive 1000–2000 year intervals. Moreover, using climate envelope models, we map the potential distributions of modern humans for each time interval and identify the regions that remained more climatically suitable and stable for modern humans through time. Results Between 46 and 22 ka the climatic niche of modern humans expanded, including periods of intense growth in niche breadth at 40 and 30 ka. Changes in seasonal water availability and technological innovations partly correlate with dynamics in niche parameters. We document a persistent climatically suitable mid-latitude belt in south Siberia linking western Europe to the Far East that may have facilitated human migration, and a potential climatic refugium in Beringia. Main conclusions The climatic niche of modern humans changed across the Late Pleistocene, as the result of both climatic and cultural changes. These populations of hunter-gatherers occupied novel climatic conditions but also remained in previously occupied areas under changing climates during the settlement of the Palaearctic. Our approach can provide clues as to where early modern humans may have overlapped in geographical and environmental space with Neanderthals or Denisovans, as evidenced by their contribution to the genetic heritage of some current populations.

The Anthropocene is witnessing a loss of biodiversity, with well-documented declines in the diversity of ecosystems and species. For intraspecific genetic diversity, however, we lack even basic knowledge on its global distribution. We georeferenced 92,801 mitochondrial sequences for >4500 species of terrestrial mammals and amphibians, and found that genetic diversity is 27% higher in the tropics than in nontropical regions. Overall, habitats that are more affected by humans hold less genetic diversity than wilder regions, although results for mammals are sensitive to choice of genetic locus. Our study associates geographic coordinates with publicly available genetic sequences at a massive scale, yielding an opportunity to investigate both the drivers of this component of biodiversity and the genetic consequences of the anthropogenic modification of nature.

Aim Island biogeography focuses on understanding the processes that underlie a set of well-described patterns on islands, but lacks a unified theoretical framework for integrating these processes. The recently proposed General Dynamic Model (GDM) of oceanic island biogeography promises a step towards this goal. Here, we present an analysis of causality within the GDM, and investigate its potential for the further development of island biogeographical theory. Further, we extend the GDM to include subduction-based island arcs and continental fragment islands. Location Based on conceptual analysis and a simulation of oceanic islands. Methods We describe the causal relationships between evolutionary and ecological processes implied by the GDM, implement them as a computer simulation, and use this to simulate two alternative geological scenarios. Results The dynamics of species richness and rates of evolutionary processes in simulations derived from the mechanistic assumptions of the GDM corresponded broadly to those initially suggested, with the exception of trends in extinction rates. Expanding the model to incorporate different scenarios of island ontogeny and isolation revealed sensitivity of evolutionary dynamics on attributes of island geology. Main conclusions We argue that the General Dynamic Model of oceanic island biogeography has the potential to form a unified framework of island biogeography, integrating geological, ecological and evolutionary processes. Our simulations highlight how the geological dynamics of distinct island types are predicted to lead to markedly different evolutionary dynamics. This sets the stage for a more predictive theory incorporating the processes governing temporal dynamics of species diversity on islands.

Aims The present-day biogeography of European amphibians has been hypothesized to have arisen from range expansion and recolonization of the northern part of the continent from southern late Pleistocene refugia, such that northern species generally possess large ranges while southerly species are mostly small-ranged. Here we test the hypothesis that these patterns are likely to be underpinned by biological traits associated with dispersal ability. We do this by analysing data for anurans and urodeles, the two main groups of European amphibians. Location Europe. Methods We built a database of biological traits (body size, fecundity, life span, habitat specialization) of European amphibians, excluding island endemics. We mapped the basic macroecological patterns of range size and position, and analysed the causal pathways for range size using structural equation models (SEMs). Results Amphibian species with a small range size are largely restricted to areas in southern Europe associated with putative Pleistocene refugia. Those present in northern Europe are exclusively large-ranged species whose distributions extend all the way from southern Europe. SEMs explained 54% of range size variation for anurans, with long life span and high fecundity being influential explanatory variables, and explained 61% of range size variation within urodeles, with measures of species fecundity being influential. Main conclusions Species that have successfully recolonized the north following deglaciation have the largest ranges for both groups of amphibians. These large-ranged species generally possess traits that indicate the potential for rapid range expansion, with differences apparent in the balance of traits between anurans and urodeles. The traits linked to northern distributions (and large range size) appear to be a mix of r and K traits, indicating that intermediate life-history strategies have proved to be optimal for range expansion into northern regions. These results integrate species biology with geographical history in explaining present-day patterns of species distribution, range size and diversity.

The general dynamic model of oceanic island biogeography (GDM) has added a new dimension to theoretical island biogeography in recognizing that geological processes are key drivers of the evolutionary processes of diversification and extinction within remote islands. It provides a dynamic and essentially non-equilibrium framework generating novel predictions for emergent diversity properties of oceanic islands and archipelagos. Its publication in 2008 coincided with, and spurred on, renewed attention to the dynamics of remote islands. We review progress, both in testing the GDM's predictions and in developing and enhancing ecological-evolutionary understanding of oceanic island systems through the lens of the GDM. In particular, we focus on four main themes: (i) macroecological tests using a space-for-time rationale; (ii) extensions of theory to islands following different patterns of ontogeny; (iii) the implications of GDM dynamics for lineage diversification and trait evolution; and (iv) the potential for downscaling GDM dynamics to local-scale ecological patterns and processes within islands. We also consider the implications of the GDM for understanding patterns of non-native species diversity. We demonstrate the vitality of the field of island biogeography by identifying a range of potentially productive lines for future research.

Aim The relationship between species number and area is of fundamental importance in macroecology and conservation science, yet the implications of different means of quantitative depiction of the relationship remain contentious. We set out (1) to establish the variation in form of the relationship between two distinct methods applied to the same habitat island datasets, (2) to explore the relevance of several key dataset properties for variation in the parameters of these relationships, and (3) to assess the implications for application of the resulting models. Locations Global. Methods Through literature search we compiled 97 habitat island datasets. For each we analysed the form of the island species–area relationship (ISAR) and several versions of species accumulation curve (SAC), giving priority to a randomized form (Ran-SAC). Having established the validity of the power model, we compared the slopes (z-values) between the ISAR and the SAC for each dataset. We used boosted regression tree and simulation analyses to investigate the effect of nestedness and other variables in driving observed differences in z-values between ISARs and SACs. Results The Ran-SAC was steeper than the ISAR in 77% of datasets. The differences were primarily driven by the degree of nestedness, although other variables (e.g. the number of islands in a dataset) were also important. The ISAR was often a poor predictor of archipelago species richness. Main conclusions Slopes of the ISAR and SAC for the same data set can vary substantially, revealing their non-equivalence, with implications for applications of species–area curve parameters in conservation science. For example, the ISAR was a poor predictor of archipelagic richness in datasets with a low degree of nestedness. Caution should be employed when using the ISAR for the purposes of extrapolation and prediction in habitat island systems.

Aim: We undertook the largest comparative study to date of the form of the island species–area relationship (ISAR) using 207 habitat island datasets and 601 true island datasets. We also undertook analyses of (a) the factors influencing z‐ and c‐values of the power (log–log) model and (b) how z and c vary between different island types. Location:Global. Methods: We used an information theoretic approach to compare the fit of 20 ISAR models to 207 habitat island datasets. Model performance was ranked according to pre‐set criteria, including metrics of generality and efficiency. We also fitted the power (log–log) model to each dataset and analysed variation in parameter estimates and model fits as a function of key dataset characteristics using linear models and constrained analysis of principal coordinates. Results: The power (nonlinear) model provided the best fit to the most datasets, and was the highest ranked model overall. In general, the more complex models performed badly. Average z‐values were significantly lower for habitat island datasets than for true islands, and were higher for mountaintop and urban habitat islands than for other habitat island types. Average c‐values were significantly lower for oceanic islands, and significantly higher for inland water‐body islands, than for habitat islands. Values of z and c were related to dataset characteristics including the ratio of the largest to smallest island and the maximum and minimum richness values in a dataset. Main conclusions: Our multimodel comparisons demonstrated the nonlinear implementation of the power model to be the best overall model and thus to be a sensible choice for general use. As the z‐value of the log–log power model varied in relation to ecological and geographical properties of the study systems, caution should be employed when using canonical values for applied purposes.

Why diversification rates vary so extensively across the tree of life remains an important yet unresolved issue in biology. Two prominent and potentially independent factors proposed to explain these trends reflect the capacity of lineages to expand into new areas of (i) geographical or (ii) ecological space. Here, we present the first global assessment of how diversification rates vary as a consequence of geographical and ecological expansion, studying these trends among 15 speciose passerine families (together approximately 750 species) using phylogenetic path analysis. We find that relative slowdowns in diversification rates characterize families that have accumulated large numbers of co-occurring species (at the 1° scale) within restricted geographical areas. Conversely, more constant diversification through time is prevalent among families in which species show limited range overlap. Relative co-occurrence is itself also a strong predictor of ecological divergence (here approximated by morphological divergence among species); however, once the relationship between co-occurrence and diversification rates have been accounted for, increased ecological divergence is an additional explanatory factor accounting for why some lineages continue to diversify towards the present. We conclude that opportunities for prolonged diversification are predominantly determined by continued geographical range expansion and to a lesser degree by ecological divergence among lineages.

International audience; Species abundance distributions (SADs) are one of the most widely used tools in macroecology, and it has become increasingly apparent that many empirical SADs can best be described as multimodal. However, only a few SAD models have been extended to incorporate multiple modes and no software packages are available to fit multimodal SAD models. In this study, we present an extension of the gambin SAD model to multimodal SADs. We derive the maximum likelihood equations for fitting the bimodal gambin distribution and generalize this approach to fit gambin models with any number of modes. We present these new functions, along with additional functions to aid in the analysis of multimodal SADs, within an updated r package ("gambin"; version 2.4.0) that enables the fitting, plotting and evaluating of gambin models with any number of modes. We use a mixture of simulations and empirical datasets to test our new models, including tests of the sensitivity of the model parameters to the number of individuals and the number of species in a sample. We show that the new multimodal gambin models perform well under a variety of circumstances, and that the application of these new models to empirical SAD and other macroecological (e.g., species range size distributions) datasets can provide interesting insights. The updated software package is simple to use and provides straightforward yet flexible statistical analyses of multimodality in SAD-type datasets.

Aim: To quantify the influence of past archipelago configuration on present-day insular biodiversity patterns, and to compare the role of long-lasting archipelago configurations over the Pleistocene to configurations of short duration such as at the Last Glacial Maximum (LGM) and the present-day.Location: 53 volcanic oceanic islands from 12 archipelagos worldwide—Azores, Canary Islands, Cook Islands, Galápagos, Gulf of Guinea, Hawaii, Madeira, Mascarenes, Pitcairn, Revillagigedo, Samoan Islands and Tristan da Cunha.Time period: The last 800 kyr, representing the nine most recent glacial–interglacial cycles. Major taxa studied: Land snails and angiosperms.Methods: Species richness data for land snails and angiosperms were compiled from existing literature and species checklists. We reconstructed archipelago configurations at the following sea levels: the present-day high interglacial sea level, the intermediate sea levels that are representative of the Pleistocene and the low sea levels of the LGM. We fitted two alternative linear mixed models for each archipelago configuration using the number of single-island endemic, multiple-island endemic and (non-endemic) native species as a response. Model performance was assessed based on the goodness-of-fit of the full model, the variance explained by archipelago configuration and model parsimony.Results: Single-island endemic richness in both taxonomic groups was best explained by intermediate palaeo-configuration (positively by area change, and negatively by palaeo-connectedness), whereas non-endemic native species richness was poorly explained by palaeo-configuration. Single-island endemic richness was better explained by intermediate archipelago configurations than by the archipelago configurations of the LGM or present-day. Main conclusions: Archipelago configurations at intermediate sea levels—which are representative of the Pleistocene—have left a stronger imprint on single-island endemic richness patterns on volcanic oceanic islands than extreme archipelago configurations that persisted for only a few thousand years (such as the LGM). In understanding ecological and evolutionary dynamics of insular biota it is essential to consider longer-lasting environmental conditions, rather than extreme situations alone.

The positive relationship between range size and abundance is one of the best-documented patterns in macroecology, but a growing number of studies from isolated tropical areas have reported negative or neutral relationships. It has been hypothesized that the combination of geographic isolation and environmental stability create selection pressures that favor narrowly specialized species, which could drive these non-positive relationships. To test this idea, we measured the range size–abundance relationships of eleven bird communities in mature and degraded forest on four islands in the Indo-Pacific, namely Flores in the Lesser Sundas, Seram in the Moluccas, and the New Caledonian islands of Grande Terre and Lifou. Local abundance data was gathered through extensive and methodologically consistent surveying, and regressed against global range size using linear mixed effect models. The relationship between range size and abundance was significantly negative across all combined mature and degraded forest communities. As negative relationships were found in degraded forest with little environmental stability, we conclude that the abundance of small-ranged species on the study islands cannot be ascribed to narrow specialization. Rather, cross-habitat community comparisons indicate that locally abundant endemic and near-endemic species adapted to a broad spectrum of local environmental conditions cause the observed negative relationships. We suspect that geographic isolation facilitates the evolution of species that are simultaneously broad-niched, small-ranged, and abundant, as water barriers limit the range expansions that would typically accompany species’ attainment of high local population densities. The consistently negative relationships found across Indo-Pacific islands represent a striking deviation from the positive range size–abundance relationship ‘rule’, and future studies should seek to determine whether the patterns detected here extend to geographically isolated mainland environments.

Summary 1. The integration of species distributions and evolutionary relationships is one of the most rapidly moving research fields today and has led to considerable advances in our understanding of the processes underlying biogeographical patterns. Here, we develop a set of metrics, the specific overrepresentation score (SOS) and the geographic node divergence (GND) score, which together combine ecological and evolutionary patterns into a single framework and avoids many of the problems that characterize community phylogenetic methods in current use. 2. This approach goes through each node in the phylogeny and compares the distributions of descendant clades to a null model. The method employs a balanced null model, is independent of phylogeny size, and allows an intuitive visualization of the results. 3. We demonstrate how this novel implementation can be used to generate hypotheses for biogeographical patterns with case studies on two groups with well-described biogeographical histories: a local-scale community data set of hummingbirds in the North Andes, and a large-scale data set of the distribution of all species of New World flycatchers. The node-based analysis of these two groups generates a set of intuitively interpretable patterns that are consistent with current biogeographical knowledge. 4. Importantly, the results are statistically tractable, opening many possibilities for their use in analyses of evolutionary, historical and spatial patterns of species diversity. The method is implemented as an upcoming R package nodiv, which makes it accessible and easy to use.

cited By 9; International audience; The species abundance distribution (SAD) has been a central focus of community ecology for over fifty years, and is currently the subject of widespread renewed interest. The gambin model has recently been proposed as a model that provides a superior fit to commonly preferred SAD models. It has also been argued that the model's single parameter (α) presents a potentially informative ecological diversity metric, because it summarises the shape of the SAD in a single number. Despite this potential, few empirical tests of the model have been undertaken, perhaps because the necessary methods and software for fitting the model have not existed. Here, we derive a maximum likelihood method to fit the model, and use it to undertake a comprehensive comparative analysis of the fit of the gambin model. The functions and computational code to fit the model are incorporated in a newly developed free-to-download R package (gambin). We test the gambin model using a variety of datasets and compare the fit of the gambin model to fits obtained using the Poisson lognormal, logseries and zero-sum multinomial distributions. We found that gambin almost universally provided a better fit to the data and that the fit was consistent for a variety of sample grain sizes. We demonstrate how α can be used to differentiate intelligibly between community structures of Azorean arthropods sampled in different land use types. We conclude that gambin presents a flexible model capable of fitting a wide variety of observed SAD data, while providing a useful index of SAD form in its single fitted parameter. As such, gambin has wide potential applicability in the study of SADs, and ecology more generally. © 2014 The Authors.

D. W. Carstensen (daniel.carstensen@gmail.com), Depto de Botânica, Laboratorio de Fenologia, Plant Phenology and Seed Dispersal Group, Inst. de Biociencias, Univ. Estadual Paulista (UNESP), Avenida 24-A no. 1515, 13506-900 Rio Claro, Sao Paulo, Brazil. – J.-P. Lessard, B. G. Holt, M. Krabbe Borregaard and C. Rahbek, Center for Macroecology, Evolution and Climate, Dept of Biology, Univ. of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark. J-PL also at: Quebec Centre for Biodiversity Science, Dept of Biology, McGill Univ., Montreal, QC H3A-1B1, Canada. BGH also at: School of Biological Sciences, Univ. of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK. MKB also at: School of Geography and the Environment, Univ. of Oxford, South Parks Road, Oxford, OX1 3CY, UK.

Next-Generation Biogeography In 1876, Alfred Russel Wallace mapped the zoogeographical regions of the world, based on the distributions and taxonomic relationships of broadly defined mammalian families. Wallace's classification of zoogeographical regions became a cornerstone of modern biogeography and a reference for a wide variety of biological disciplines, including global biodiversity and conservation sciences. Holt et al. (p. 74 , published online 20 December) present a next-generation map of wallacean zoogeographic regions, incorporating phylogenetic data on >20,000 vertebrate species to discern and characterize their natural biogeographic patterns.

Regional variation in clade richness can be vast, reflecting differences in the dynamics of historical dispersal and diversification among lineages. Although it has been proposed that dispersal into new biogeographic regions may facilitate diversification, to date there has been limited assessment of the importance of this process in the generation, and maintenance, of broad-scale biodiversity gradients. To address this issue, we analytically derive biogeographic regions for a global radiation of passerine birds (the Corvides, c. 790 species) that are highly variable in the geographic and taxonomic distribution of species. Subsequently, we determine rates of historical dispersal between regions, the dynamics of diversification following regional colonization, and spatial variation in the distribution of species that differ in their rates of lineage diversification. The results of these analyses reveal spatiotemporal differences in the build-up of lineages across regions. The number of regions occupied and the rate of transition between regions both predict family richness well, indicating that the accumulation of high clade richness is associated with repeated expansion into new geographic areas. However, only the largest family (the Corvidae) had significantly heightened rates of both speciation and regional transition, implying that repeated regional colonization is not a general mechanism promoting lineage diversification among the Corvides.

Aim The general dynamic model (GDM) of oceanic island biogeography integrates rates of immigration, speciation and extinction in relation to a humped trajectory of island area, species carrying capacity and topographic complexity through time, based on a simplified island ontogeny. In practice, many islands have more complex ontogenies, featuring surfaces of varying age. Here, we extend the GDM to apply at a local scale within islands, and test the predictions analytically within individual islands. Location El Hierro, La Palma and Tenerife (Canary Islands). Methods Following the GDM logic, we derive predictions for the distributions and richness of single island endemics (SIEs) across island landscapes of different age. We test these predictions by means of generalized linear models and binominal tests using gridded species occurrence data for vascular plant SIE species and a set of climatic, topographic and terrain age variables. We also examined phylogenetic divergence times for a subset of endemic lineages. Results Geological age, in interaction with slope, and topographic variables, best explained SIE richness at the landscape scale. About 70% of SIEs had ranges strongly biased to, or largely restricted to old terrain. Available phylogenetic divergence times of SIEs of radiated plant lineages suggested an origin on the older parts of the islands. Metrics of anthropogenic disturbance and habitat availability were unrelated to the observed SIE pattern. Main conclusions Our findings support the hypothesis that SIEs have evolved and accumulated on older and topographically complex terrain, while colonization processes predominate on the youngest parts. These results imply that evolutionary processes shape species distributions at the landscape scale within islands. This opens the perspective of extending the GDM framework to understand processes at a local scale within individual islands.

The concept of species-level heritability is widely contested. Because it is most likely to apply to emergent, species-level traits, one of the central discussions has focused on the potential heritability of geographic range size. However, a central argument against range-size heritability has been that it is not compatible with the observed shape of present-day species range-size distributions (SRDs), a claim that has never been tested. To assess this claim, we used forward simulation of range-size evolution in clades with varying degrees of range-size heritability, and compared the output of three different models to the range-size distribution of the South American avifauna. Although there were differences among the models, a moderate-to-high degree of range-size heritability consistently leads to SRDs that were similar to empirical data. These results suggest that range-size heritability can generate realistic SRDs, and may play an important role in shaping observed patterns of range sizes.

There is a long tradition in ecology of evaluating the relative contribution of the regional species pool and local interactions on the structure of local communities. Similarly, a growing number of studies assess the phylogenetic structure of communities, relative to that in the regional species pool, to examine the interplay between broad-scale evolutionary and fine-scale ecological processes. Finally, a renewed interest in the influence of species source pools on communities has shown that the definition of the source pool influences interpretations of patterns of community structure. We use a continent-wide dataset of local ant communities and implement ecologically explicit source pool definitions to examine the relative importance of regional species pools and local interactions for shaping community structure. Then we assess which factors underlie systematic variation in the structure of communities along climatic gradients. We find that the average phylogenetic relatedness of species in ant communities decreases from tropical to temperate regions, but the strength of this relationship depends on the level of ecological realism in the definition of source pools. We conclude that the evolution of climatic niches influences the phylogenetic structure of regional source pools and that the influence of regional source pools on local community structure is strong.

In this paper we present a concept for using presenceabsence data to recover information on the population dynamics of predatorprey systems. We use a highly complex and spatially explicit simulation model of a predatorprey mite system to generate simple presenceabsence data: the number of patches with both prey and predators, with prey only, with predators only, and with neither species, along with the number of patches that change from one state to another in each time step. The average number of patches in the four states, as well as the average transition probabilities from one state to another, are then depicted in a state transition diagram, constituting the ‘‘footprints’’ of the underlying population dynamics. We investigate to what extent changes in the population processes modeled in the complex simulation (i.e. the predator’s functional response and the dispersal rates of both species) are reflected by different footprints. The transition probabilities can be used to forecast the expected fate of a system given its current state. However, the transition probabilities in the modeled system depend on the number of patches in each state. We develop a model for the dependence of transition probabilities on state variables, and combine this information in a Markov chain transition matrix model. Finally, we use this extended model to predict the long-term dynamics of the system and to reveal its asymptotic steady state properties.

Dispersal is one of the key processes in shaping distributional ranges and community assemblages, but we know little about animal dispersal at the individual, population, or community levels, or about how dispersal correlates with the establishment and colonization of new areas. This is largely due to difficulties in studying individual movements at the relevant spatiotemporal scale, leading to a gap between the direct study of dispersal and our understanding of the build-up of larger-scale biodiversity. Recent advances in tracking technology make it possible to bridge this gap. We propose a way to link movement, dispersal, ecology, and biogeography. In particular, we offer a framework to scale-up from processes at the individual level to global patterns of biodiversity.

The general dynamic model of oceanic island biogeography (GDM) has added a new dimension to theoretical island biogeography in recognizing that geological processes are key drivers of the evolutionary processes of diversification and extinction within remote islands. It provides a dynamic and essentially non-equilibrium framework generating novel predictions for emergent diversity properties of oceanic islands and archipelagos. Its publication in 2008 coincided with, and spurred on, renewed attention to the dynamics of remote islands. We review progress, both in testing the GDM's predictions and in developing and enhancing ecological-evolutionary understanding of oceanic island systems through the lens of the GDM. In particular, we focus on four main themes: (i) macroecological tests using a space-for-time rationale; (ii) extensions of theory to islands following different patterns of ontogeny; (iii) the implications of GDM dynamics for lineage diversification and trait evolution; and (iv) the potential for downscaling GDM dynamics to local-scale ecological patterns and processes within islands. We also consider the implications of the GDM for understanding patterns of non-native species diversity. We demonstrate the vitality of the field of island biogeography by identifying a range of potentially productive lines for future research.

The Corvides (previously referred to as the core Corvoidea) are a morphologically diverse clade of passerine birds comprising nearly 800 species. The group originated some 30 million years ago in the proto-Papuan archipelago, to the north of Australia, from where lineages have dispersed and colonized all of the world's major continental and insular landmasses (except Antarctica). During the last decade multiple species-level phylogenies have been generated for individual corvoid families and more recently the inter-familial relationships have been resolved, based on phylogenetic analyses using multiple nuclear loci. In the current study we analyse eight nuclear and four mitochondrial loci to generate a dated phylogeny for the majority of corvoid species. This phylogeny includes 667 out of 780 species (85.5%), 141 out of 143 genera (98.6%) and all 31 currently recognized families, thus providing a baseline for comprehensive macroecological, macroevolutionary and biogeographical analyses. Using this phylogeny we assess the temporal consistency of the current taxonomic classification of families and genera. By adopting an approach that enforces temporal consistency by causing the fewest possible taxonomic changes to currently recognized families and genera, we find the current familial classification to be largely temporally consistent, whereas that of genera is not.

We present a framework to measure the strength of environmental filtering and disequilibrium of the species composition of a local community across time, relative to past, current, and future climates. We demonstrate the framework by measuring the impact of climate change on New World forests, integrating data for climate niches of more than 14 000 species, community composition of 471 New World forest plots, and observed climate across the most recent glacial–interglacial interval. We show that a majority of communities have species compositions that are strongly filtered and are more in equilibrium with current climate than random samples from the regional pool. Variation in the level of current community disequilibrium can be predicted from Last Glacial Maximum climate and will increase with near-future climate change.

In this study, we investigate patterns in the prevalence of dynamic range-abundance relationships of the Danish avifauna, using breeding bird atlases from 1971 to 1974 and from 1993 to 1996. We focus on differences between common and rare species by dividing the assemblage into range-size quartiles. The trend in total population size was determined using an index. Range was determined as grid cell occupancy and standardized to facilitate comparisons between common and rare species. While narrow-ranging species showed strong and consistent range-abundance relationships, the relationships for widespread species were weak and exhibited considerable variation. This may be due to differences in patterns of resource use, since widespread species generally have wider niches, and so may be less affected by resource-based factors linking range and abundance. Since a tight and dynamic relationship is upheld for rare species, monitoring strategies based on range size surveys seem viable.

Kreft and Jetz’s critique of our recent update of Wallace’s zoogeographical regions disregards the extensive sensitivity analyses we undertook, which demonstrate the robustness of our results to the choice of phylogenetic data and clustering algorithm. Their suggested distinction between “transition zones” and biogeographic regions is worthy of further investigation but is thus far unsubstantiated.

New species are sometimes known to arise as a consequence of the dispersal and establishment of populations in new areas. It has nevertheless been difficult to demonstrate an empirical link between rates of dispersal and diversification, partly because dispersal abilities are challenging to quantify. Here, using wing morphology as a proxy for dispersal ability, we assess this relationship among the global radiation of corvoid birds. We found that species distributions are associated with wing shape. Widespread species (occurring on both islands and continents), and those that are migratory, exhibit wing morphologies better adapted to long-distance flight compared with sedentary continental or insular forms. Habitat preferences also strongly predict wing form, with species that occur in canopies and/or areas of sparse vegetation possessing dispersive morphologies. By contrast, we found no significant differences in diversification rates among either the migratory or habitat classifications, but species distributed in island settings diversify at higher rates than those found on continents. This latter finding may reflect the elevated dispersal capabilities of widespread taxa, facilitating the radiation of these lineages across insular areas. However, as the correlations between wing morphology and diversification rates were consistently weak throughout our dataset, this suggests that historical patterns of diversification are not particularly well reflected by present-day wing morphology.

Despite decades of research, the roles of climate and humans in driving the dramatic extinctions of large-bodied mammals during the Late Quaternary period remain contentious. Here we use ancient DNA, species distribution models and the human fossil record to elucidate how climate and humans shaped the demographic history of woolly rhinoceros, woolly mammoth, wild horse, reindeer, bison and muskox.Weshow that climate has been a major driver of population change over the past 50,000 years.However, each species responds differently to the effects of climatic shifts, habitat redistribution and human encroachment. Although climate change alone can explain the extinction of some species, such as Eurasian muskox and woolly rhinoceros, a combination of climatic and anthropogenic effects appears to be responsible for the extinction of others, including Eurasian steppe bison and wild horse. We find no genetic signature or any distinctive range dynamics distinguishing extinct from surviving species, emphasizing the challenges associated with predicting future responses of extant mammals to climate and human-mediated habitat change

One of the cornerstones of macroecological research is theongoing effort to understand large-scale patterns of speciesrichness. These patterns are emergent properties of thedistributional ranges of individual species, as they areformed by the overlap of species ranges in a given area.As such, the sizes of ranges, and the processes controllingtheir geographical location, are key determinants of richnesspatterns. However, a satisfactory link between range sizedistributions, the spatial location of individual ranges, andspecies richness has been slow to emerge.To forge this link, a central part is the role of speciesassociations in determining the composition of species ina defined area. Overlap between species ranges may arisebecause species have similar ecologies (Webb 2000), forhistorical reasons of dispersal (Svenning et al. 2008), ormay simply be random, because ranges are constrained bythe shape of the geographical domain (Colwell and Lees2000, Jetz and Rahbek 2001). However, although speciesinteractions have consistently been shown to affect speciesco-occurrence at local scales (Gotelli and McCabe 2002),the importance of species associations for distributionaloverlap at biogeographical scales remains a central questionfor macroecology (Gotelli et al. 1997, in press).Species’ ranges are usually continuous at large scales, andas a consequence, the species richness values of closelylocated sites are not independent. This means that thespatial pattern of species richness cannot be explained byanalyzing sites as a set of independent points in a regression(Legendre 1993). Spatial regression methods solve thestatistical issue of autocorrelation (Rangel et al. 2006),but a simplistic use of these statistics risks missing the mainpoint. Spatial patterning is not a statistical issue it is aninherent quality of biogeographical data (Rahbek andGraves 2000, Diniz-Filho et al. 2003). In the light ofthis, recent attention has focused on developing conceptualand analytical tools for macroecological analysis that dealexplicitly with species’ ranges.One important advance is the concept of the ‘‘dispersionfield’’, developed by Graves and Rahbek (2005). Thedispersion field is the set of geographical ranges of allspecies that occur in a given site. Just as the continentalspecies richness pattern is created by the overlap of allspecies in a continent, the dispersion field can be visualizedas the pattern created by overlapping the ranges of allspecies occurring in a given cell (Fig. 1). These dispersionfields have striking geometric shapes, and have a number ofpromising applications.First, it has been argued that the geometric shape ofdispersal fields are an approximation to the regional speciessource pool (Graves and Rahbek 2005). The source poolplays a key role in theories of community assembly, butthe concept has been consistently difficult to pin down(Gotelli and Graves 1996). Even more importantly,dispersion fields visualize the species associations thatcreate richness patterns. Hence, they provide an opportu-nity for more stringent tests of ecological hypotheses forspecies richness than standard regression methods. Agrowing research paradigm in macroecology is to replacecurve-fitting methods with mechanistic models of rangeplacement (Rahbek et al. 2007, Rangel et al. 2007, Gotelliet al. 2009). Such models also generate predictions on thestructure of dispersion fields. Comparing both richnesspatterns and dispersion fields to modeled patterns thusconstitutes an opportunity for validation of these modelsat two hierarchical levels, a standard for pattern-orientedmodeling (Grimm et al. 2005).A promising approach for investigating the linkbetween range sizes and richness patterns has recentlybeen developed by Arita et al. (2008). This approach isbased on dispersion fields, and starts with the presenceabsence matrix of sites versus species. In this matrix, thecolumns are sites, rows are species, and the matrixelements represent the presence (1) or absence (0) ofa given species in a particular site (Gotelli 2000). Thestrength of the presence absence matrix is that it com-bines information on species richness (which are thecolumn sums), range sizes (which are the row sums),and the co-occurrence of species (which can be mea-sured by the degree of co-variance in the matrix). How-ever, the presence absence matrix is not easy to visualizegraphically.

The positive relationship between a species’ geographic distribution and its abundance is one of ecology’s most well-documented patterns, yet the causes behind this relationship remain unclear. Although many hypotheses have been proposed to account for distribution-abundance relationships, none have attained unequivocal support. Accordingly, the positive association in distribution-abundance relationships is generally considered to be due to a combination of these proposed mechanisms acting in concert. In this review, we suggest that much of the disparity between these hypotheses stems from differences in terminology and ecological point of view. Realizing and accounting for these differences facilitates integration, so that the relative contributions of each mechanism may be evaluated. Here, we review all the mechanisms that have been proposed to account for distribution-abundance relationships, in a framework that facilitates a comparison between them. We identify and discuss the central factors governing the individual mechanisms, and elucidate their effect on empirical patterns.

BACKGROUND Ever since Darwin, natural scientists have turned to islands for inspiration and for model systems. For the past half century, they have done so largely within the paradigm established by Robert H. MacArthur and Edward O. Wilson’s Theory of Island Biogeography , which provided a quantitative, dynamic framework, based upon assumptions of geographically predictable patterns of immigration, extinction, and speciation. Although this approach has proven productive, its application to remote archipelagos and evolutionary time scales has been hampered by a rather static view of islands themselves, despite mounting evidence of their dynamism as platforms. We review recent progress in integrating the largely ecological thinking of their theory with insights on the longer-term dynamics of both the islands and their biotas. ADVANCES Classification and analysis of marine islands by their geophysical dynamics, and of their species by how they colonized, provides a step toward a more nuanced biogeography out of which new insights are already emerging. This perspective is exemplified by the general dynamic model of oceanic island biogeography, which predicts how immigration, speciation, and extinction respond to the typical life cycle of hotspot islands, with phases of emergence, development, and submergence. The model successfully predicts such emergent patterns as the occurrence of peak diversification on youthful, expanding islands with maximum vacant niche space. Diversity patterns analyzed for large numbers of data sets have confirmed the importance of in situ evolutionary dynamics on remote archipelagos, which typically possess steep island species–area relationships, especially for endemic taxa. We may infer that variations in propagule flow among islands within archipelagos are important in modulating these emergent diversity patterns. There is, for example, good support for an “island progression rule” in which older land masses donate colonists to younger islands (consistent with the generalization of islands as “sinks”), but there is also increasing evidence of “reverse colonization,” including from islands to continental regions. Advances are also being made in linking such island biogeographical models with the classic traits and syndromes of insular species, although this first demands that previous generalizations are rigorously reexamined using expanded data sets and modern techniques of analysis. A classic insular syndrome is the loss of dispersability of formerly dispersive species following island colonization, for which there is now good evidence for several taxa, including many genera of land birds. Yet, paradoxically, and perhaps controversially, it has also been inferred that many species of plants lacking specialized dispersal adaptations can colonize quite remote islands, often by nonstandard means of transport. Unfortunately, island evolutionary syndromes, such as loss of flight in birds, frequently predispose species to heightened extinction risk when islands are colonized and transformed by humans, as we also document. OUTLOOK Developments in theory and in analytical and modeling capabilities within biological and Earth system science, and the pooling of large numbers of data sets, enhancing statistical power, collectively hold the promise of a new synthesis in island biogeography. This synthesis will need to accommodate evidence of the long-term dynamics of remote island systems, whereby some lineages persist far longer than any particular island platform, while others founder as their sole island home sinks under the waves. The promise is of a biogeography in the tradition of the MacArthur–Wilson theory, generating and testing predictive models, but extended to accommodate a more sophisticated suite of insular geological and environmental dynamics, combined with a fuller understanding of patterns and processes of gene flow within and between archipelagos.