Benjamin R. Shipley

The distribution of organisms across Earth provides insight into the origin and maintenance of biodiversity. Abundant fossil evidence suggests taxa have undergone substantial range changes over time. However, biogeographic theory and models often tend to assume that clades originated in the regions where we observe them today. Understanding the prevalence of geographically dynamic clades across the tree of life provides a way to evaluate these assumptions, thereby refining key evolutionary hypotheses. We provide a review of such range-shifting clades using a two-pronged approach. First, literature searches uncovered examples across most major multicellular groups (comprising 129 clades with mismatches between fossil and modern ranges). Concurrently, we used the well-sampled mammalian fossil record as a case study, finding that more than half of its terrestrial families (51%) had substantial (>1000 km) geographic mismatches. Geographically dynamic lineages are both common and widespread, but despite their ubiquity, fossil–modern mismatches have only recently been integrated into phylogenetic and biogeographic methods and no comprehensive overview of their advantages and challenges exists. We therefore review the current state of the field and discuss case studies where fossil evidence reshaped prevailing biogeographic theory. Biogeographers must take advantage of these rich fossil histories to better elucidate evolutionary theory across space and time.

Aim: Species may not fully track shifting climatic conditions when dispersal is limited, yet how species‐specific dispersal constraints scale up to shape biodiversity redistribution across taxa remains unclear. We evaluated how dispersal limitation modifies projected biodiversity dynamics under climate change. Location: North America. Time Period: Contemporary to late 21st century. Major Taxa Studied: Terrestrial vertebrates. Methods: We developed species distribution models for 256 terrestrial vertebrate species spanning dispersal rates from 0 to ~100 km/year. We compared climate‐driven projections based on climatic suitability with projections incorporating species‐specific dispersal constraints. We further assessed how dispersal capacity influences habitat accessibility and projected overlap with major land‐cover categories and protected areas. Results: Dispersal limitation substantially altered the magnitude and spatial structure of projected biodiversity change. Climate‐driven projections predicted increasing species richness and poleward range expansion, whereas dispersal‐limited projections suppressed leading‐edge expansion, amplified range contraction and generated extensive climatically suitable but inaccessible habitat. These effects intensified under stronger climate forcing and were most pronounced at high latitudes. Species with lower dispersal capacities experienced substantially greater mismatches between climatically suitable and accessible habitat. Dispersal limitation also altered projected landscape overlap: overlap with forests, wetlands, and protected areas increased under climate‐driven projections but declined when dispersal constraints were incorporated, whereas dispersal limitation attenuated projected increases or amplified projected declines in other landscape categories. Main Conclusions: Species‐specific dispersal capacity acts as a biological filter on climate tracking, and climate‐driven projections may therefore overestimate species' ability to track environmental change. These species‐level constraints scale up to alter continental biodiversity redistribution and its spatial correspondence with different landscape types. Incorporating dispersal processes is therefore essential for projecting future biodiversity change and informing conservation planning.

The number of species introduced outside of their historical ranges by human activity continues to rise ¹ . A subset of these species establishes, form self-sustaining populations, and some – invasive alien species – go on to cause substantial harm to biodiversity and ecosystems ² . Preventing new invasive alien species from establishing is the key focus of interventions, because post-establishment management is costly and often fails ^3,4 . However, it remains unclear how effective multilateral efforts have been in curbing the rise. Here we show that the emergence of new invasive alien species across countries is slowing, and trends are similarly negative across geographically diverse countries. Using data and modelling advances, we find a 35% reduction in the establishment of new invasive alien species over a policy-relevant 50-year time frame. The findings directly inform the assessment of progress for the invasive alien species target of the Kunming-Montreal Global Biodiversity Framework ⁵ , and provide a global baseline for monitoring rates of invasive alien species establishment. Furthermore, the slowdown suggests that policy and investment over recent decades to prevent invasive alien species from entering and establishing in countries have had a positive effect.

Palaeontology sits at the intersection of Earth and life sciences. The fossil record is simultaneously geological and biological in nature, offering a unique window into how Earth developed into what we see today. This long view of Earth system processes has allowed researchers to study how the presence of life has influenced the geosphere, whilst the geosphere has in turn been a powerful force in structuring diversity and ecology. In this closing chapter, we outline the geological and palaeobiological perspectives on the use of the fossil record and introduce a synthetic framework for discussing palaeobiogeographic trends in Earth-life interactions, discriminating between biogeography in reconstructed space and the geography of fossil distributions today. Following from the legacy of LRM Cocks, and his contemporaries, we discuss the utility of fossil data for constraining reconstructions of past earths and compare geological and palaeontological perspectives on biotic ranges on a dynamic Earth.

Identifying the drivers of variation in extinction intensity and selectivity across Earth’s history is essential for explaining past biodiversity patterns and for predicting biological responses to environmental change. Here we investigate the role of coastline geometry and paleogeographic boundary conditions in shaping extinction risk for taxa over the past 540 million years. Paleogeography significantly influenced extinction risk for shallow-marine-restricted invertebrates over the Phanerozoic. Taxa with dispersal pathways that were disproportionately long compared to the latitudinal range traversed, as seen along east–west–oriented coastlines, islands, or inland seaways, consistently showed higher extinction risk compared to taxa whose dispersal pathways allowed more direct movement across latitudes. This information can be leveraged to study how marine invertebrates are responding to present-day climate change. We find evidence of differential dynamics for shallow marine invertebrates today that is dependent on geographic context.

Aim: Cave fish, the largest aquatic vertebrates in karst ecosystems, rely heavily on bat guano as a nutrient source. However, ongoing environmental change is degrading cave habitats and altering bat distributions. This study aims to assess how climate‐driven bat migration affects cave fish distributions in China, providing insights for biodiversity conservation. Location: China. Methods: We developed ensemble species distribution models (ensemble SDMs) for cave bats and cave fish, integrating current and projected climate data to simulate historical and future distributions. Cave bat richness was used as a proxy for food resource availability for cave fish. We then quantified changes in cave fish richness under different climate scenarios and evaluated the amplifying effect of bat migration. Results: Both cave bats and cave fish exhibit overlapping richness hotspots in southern China, strongly associated with fragmented karst landscapes. Under future climate scenarios, the cave bat richness center is projected to shift northwestward, with greater displacement under high‐emission conditions. Cave fish richness is predicted to decline due to climate stress alone, but when accounting for bat migration, losses are amplified by 12–40 times. Main Conclusions: Climate‐induced shifts in cave bat distributions may drastically intensify habitat and nutrient limitations for cave fish, exacerbating biodiversity loss. These findings highlight the importance of integrating biotic interactions and trophic dependencies in species distribution modelling and conservation planning. The study provides a framework for prioritising cave ecosystem protection under future environmental change.

Aim: Cave fish have long fascinated biologists due to their unusual morphology, biology and physiology. Here, we developed the first database of cave fish occurrences, provided the first map of cave fish diversity patterns and evaluated how environmental changes are threatening cave fish diversity across the globe. Location: Global. Time Period: 21st century. Major Taxa Studies: Cave fish, classified as Stygobionts and Stygophiles, are widespread across the phylogeny of freshwater fish, with more than one‐third of fish orders (17/45) and one‐fifth of freshwater fish families (37/185). Methods: We collected 1017 records of cave fish through a review of 378 publications and field surveys. We then used species distribution models to project the current and future global distribution of cave fish under varying climatic and geomorphic conditions, while assessing threats posed by multiple environmental stressors. Results: We show that a few places in South America and Asia host a striking richness in cave fish species, whereas other regions are almost free from such species. We moreover reveal that almost two‐thirds of the species are not formally named and that knowledge of cave fish diversity is lacunary in several regions from the Global South. Limited dispersal capacities of cave fish are expected to result in substantial habitat loss, as newly suitable or restored habitats remain inaccessible, thereby pushing species at risk of extinction across the globe. Arsenic contamination in groundwater and dam construction were identified as further threats to cave fish in karst and non‐karst regions, respectively. Conclusions: We mapped the global patterns of cave fish diversity and richness, assessed exposure risks under changing environmental conditions and revealed substantial knowledge gaps. Our work constitutes a primer for cave fish ecology and paves the way for further studies on the impact of global changes on the fragile but unique subterranean ecosystems.

Island mammals have influenced ecological and evolutionary theory since Darwin, and many of them provide textbook examples of the dramatic morphological evolution that often occurs in island communities. However, patterns of evolution in the climatic niches of island mammals have yet to be fully explored. Several hypotheses explaining niche divergence in island species have been introduced, linking niche evolution to increased competition among closely related or sympatric species, and as a by‐product of morphological evolution or geographical patterns. Here, we evaluate these hypotheses using closely related species pairs (sister taxa). We characterized the climatic niches of island endemic species and their closest relatives and calculated two metrics of niche divergence between the species (niche overlap and centroid distance). We compared these metrics between island endemics that have island‐dwelling sister taxa and those that have mainland‐dwelling sister taxa. We then related the degree of niche divergence to phylogenetic relatedness between the sister taxa, sympatry, morphological trait differences and island characteristics (isolation, size, age). Overall, despite significant niche divergence across species pairs, we found little evidence that competition or biotic interactions drive large‐scale climatic niche evolution in island mammals. Niche divergence in island‐endemic mammals is not driven by sympatry with their closest relatives, nor is it linked to phylogenetic relatedness. Furthermore, the phenotypic evolution of island‐endemic species does not lead to corresponding evolution in climatic niches. Instead, abiotic, geographical patterns appear to drive niche divergence in these species. Sister taxa that were more geographically isolated from each other had significantly lower niche overlaps. Island‐endemic mammals that live in montane regions likewise diverged from their closest relatives. These results suggest that competition between related species on islands may lead to niche partitioning only on local scales and that niche evolution in island‐endemic mammals may occur primarily in response to geographical patterns.

Aim: Biological diversity is shaped by processes occurring at different spatial and temporal scales. However, the direct influence of the spatial and temporal scale on patterns of occupancy is still understudied. Today, occupancy is often negatively correlated with species richness, but it is unknown whether this relationship is scale dependent and consistent through time. Here, we use datasets of contemporary and paleontological communities to explore the occupancy‐richness relationship across space and time, examining how scale influences this relationship.Location: Varying spatial extents with global coverage.Time: Varies from 7 mya to 2021 CE.Taxa: foraminifera, mammals, birds, fish, and plants.Methods: We gathered datasets spanning different spatial, temporal, and taxonomic extents. We binned each dataset into distinct time periods and spatially subsampled them into regional pools of varying sizes. We calculated regional occupancy and richness for each pool, measuring the strength of the relationship between the two. Using linear mixed models, we related the occupancy‐richness relationship to the size of the regional pools, overall species richness, and climatic changes through time.Results: We observed nearly ubiquitous negative occupancy‐richness relationships across taxa, spatial scale, and time. The size of the regional pools and time bins had no consistent effects on the strength of the relationship, but the strength of the negative relationship varied substantially among taxa, with foraminifera and North American pollen showing weaker relationships than mammals and birds. Changes in this relationship through time were not driven by climatic perturbations but by the species richness observed across all regional pools.Conclusions: Patterns of regional richness and occupancy are consistently negatively related and independent of spatial and temporal scale and of direct climatic changes. However, differences in the ecology of species (e.g., dispersal ability) and changes in biodiversity and community composition through time may cause fluctuations in the strength of the occupancy‐richness relationship.

Endemic (small-ranged) species are distributed non-randomly across the globe. Regions of high topography and stable climates have higher endemism than flat, climatically unstable regions. However, it is unclear how these environmental conditions interact with and filter mammalian traits. Here, we characterize the functional traits of highly endemic mammalian assemblages in multiple ways, testing the hypothesis that these assemblages are trait-filtered (less functionally diverse) and dominated by species with traits associated with small range sizes. Compiling trait data for more than 5000 mammal species, we calculated assemblage means and multidimensional functional metrics to evaluate the distribution of traits across each assemblage. We then related these metrics to the endemism of global World Wildlife Fund ecoregions using linear models and phylogenetic fourth-corner regression. Highly endemic mammalian assemblages had small average body masses, low fecundity, short lifespans and specialized habitats. These traits relate to the stable climate and rough topography of endemism hotspots and to mammals' ability to expand their ranges, suggesting that the environmental conditions of endemism hotspots allowed their survival. Furthermore, species living in endemism hotspots clustered near the edges of their communities’ functional spaces, indicating that abiotic trait filtering and biotic interactions act in tandem to shape these communities.