Reshaping biogeography: Perspectives on the past, present and future

Biogeography, as any scientific discipline, advances when new concepts, methodologies and tools allow us to see the world in different ways: plate tectonics reshaped the study of distributions (Hess, 1962; Wegener, 1915), deep sea submersibles revealed life at hydrothermal vents (Corliss et al., 1979; Lonsdale, 1977), phylogeography was born through advances in sequencing (Avise et al., 1987) and macroecology originated in a novel top-down statistical view (Brown & Maurer, 1989), to name but a few. We are in an age of innovation during which the rapid emergence of new techniques can provide unparalleled information from the smallest to the largest spatial scales, from individuals to communities, and from seconds to millennia. Moreover, acquired data are more numerous and more accessible than ever before—even beyond traditional research communities, in many cases to unprecedentedly vast and increasingly global epistemic communities—and theory more refined. Integrating the data created by new techniques in emerging conceptual frameworks will require new analytical tools and ways of thinking and possibly new ways of doing biogeography. Success will be measured in our ability to reshape the frontiers of human knowledge on the geography of life, gain deeper insight into fundamental biogeographic processes, make detailed predictions, and mitigate biodiversity and climate crises. Numerous challenges to attaining those goals remain. For example, how should we (1) close gaps and shortfalls and identify biases in global knowledge of biodiversity, (2) leverage descriptive statistics—whether frequentist or Bayesian—with ever more data-intensive and powerful AI architectures to reveal hidden patterns, mechanisms and interactions, (3) collect, curate and access data that permit modelling of processes in near-real-time in a rapidly changing world, and (4) validate and improve models and develop new theory? These challenges assail many domains of knowledge; our interest is in how overcoming them can transform biogeography across fields and scales into an holistic and operational discipline. Reshaping biogeography also will require an understanding of how the discipline operates: its history, current status and potential futures. This pursuit will benefit from drawing more on the methods of history and philosophy of science in which biogeography has only occasionally been entrained (e.g. Hull, 1988). Philosophical contributions have rarely driven debate in mainstream biogeography (a Web of Science TOPIC search for ‘philosophy’ in Journal of Biogeography on 30 April 2023 returned only 9 papers since 1990) despite material that is highly relevant (e.g., Reutlinger et al., 2021). This scarcity is intriguing and an opportunity, given the rich philosophical discussions in closely allied fields such as evolutionary biology and systematics (e.g. Ghiselin, 1997; Gould, 2002; Mayr, 1993, 1994; O'Malley, 2010) and that if we engage with the epistemology of our discipline we should learn a great deal. To this end, Journal of Biogeography (JBI) invited papers for a special section to explore the contributions of innovations in tools, data and models, their application, and their potential to shape the future of biogeographical research. We also invited a series of perspectives from leading biogeographers, reflecting on key papers in JBI's back catalogue (50th anniversary compilation I, 50th anniversary compilation II) to contextualize modern biogeography and look into the near future. We encouraged multidisciplinary research teams and new ideas or approaches as well as individualistic papers that may challenge existing norms. Here, we launch the special section Reshaping Biogeography—Perspectives on the Past, Present and Future with the first four contributions: two research articles (Farquhar et al., 2022; Olivos et al., 2023) and two perspectives (Heads, 2023; Mishler, 2023). We briefly consider how they impinge on debates in biogeography, and look forward to a suite of additional papers in the coming months. One persistent challenge in biogeography has been obtaining sufficient data to study patterns in detail, particularly for rare species. Farquhar et al. (2022) address this challenge in an increasingly common way: rather than relying on costly and time-consuming field efforts, they leveraged the power of citizen science via the iNaturalist biodiversity database to obtain georeferenced records. Furthermore, to improve geographical coverage they also gathered records from Facebook, Instagram and Flickr. Pairing these data with point pattern analyses and an N-dimensional hypervolume approach, Farquhar et al. demonstrated a cline in the relative densities of two colour morphs of the tree goanna (Varanus varius), a monitor lizard, in Eastern Australia: one morph exploits areas that are relatively more arid, receive more solar irradiation and experience a broader range of thermal extremes. The study shows the potential for citizen science platforms to provide alternatives to expensive time-consuming field studies (among other benefits), representing one of the greatest cultural shifts in science in recent decades. However, citizen (community) science is not without its own challenges (Elliot & Rosenberg, 2019). Olivos et al. (2023) also tackle biogeography in data-poor regions, but in the context of assessing the risk of aquatic biological invasions. Invasions have emerged as one of the most significant—but debated—threats to global biodiversity (Bellard et al., 2016, 2022; Briggs, 2010). The debate, and the potential consequences, highlight the urgency of gaining better understanding. Olivos and colleagues' approach is to build models that estimate how covariates influence invasion potential. Importantly, Olivos et al. fill two key gaps. First, they developed a framework for estimating invasion potential in riverine systems (methods from other, commonly studied systems are largely useless for species in intricate stream networks). Second, when data were of insufficient quantity and quality, they modelled stages of the life cycle and stacked the models, holistically identifying environmental resistance and predicting invasion risk. Using these approaches, Olivos et al. identified a highly heterogeneous distribution of invasion resistance for three invasive aquatic species, which can guide the control of invasion risk, both for identifying research and management priorities. Moreover, the methodology can be applied to other species and regions; a swift economical model is particularly significant for regions where data are scarce. Furthermore, it may advance our understanding of the impacts of scarcity of data on biogeographical inferences, or ‘shortfalls’ (Diniz Filho et al., 2023; Hortal et al., 2015). The origins and distribution of species is also of interest to Heads (2023), who reflects on the relationships between distribution patterns and earth history in New Caledonia. Heads' concerns are fourfold: (1) popular methods to analyse space and time in biogeography are unsound, (2) fossil calibrations of molecular clocks can be suspect, (3) ancestral-area algorithms uncritically generate centres of origin, and (4) the assumption that New Caledonia was completely flooded necessitates long-distance dispersal, an infrequent event, to become frequent. Heads has a different way of looking at New Caledonian biogeography—a narrative synthesis of biogeography and geology—and concludes that New Caledonian taxa evolved largely on or around their present terranes by vicariance among widespread ancestors. In this case, disjunct distributions between New Caledonian taxa and their geographically distant close relatives may be explained not by dispersal, but by phylogenetic breaks related to tectonics. Even during marine transgressions, clades persisted as metapopulations colonizing new lands as they formed. This view of biogeography may be tested on other remote islands, such as the Galapagos, and like Geogenomics, offers a welcome synthesis between biology and geology. Mishler (2023) approaches the problem of understanding distributions from another novel angle. As Mishler notes, the overwhelming majority of biogeography is species-centric. Biogeographical studies predominantly concern themselves with species: species richness, species–area relationships, species abundance distributions, the origins of species, species distribution models, the leaves on the tips of phylogenetic trees are typically Latin binomials, we study phylogeography species-by-species and so on. But Mishler argues for a rank-free approach, using differentially diverged lineages of relative nestedness in a continuous hierarchy. The approach—‘spatial phylogenetics’—has a variety of merits. It avoids the debates between splitters versus lumpers that plague species-based estimates of biodiversity and taxonomic progress (Stropp et al., 2022); it means that undescribed taxa are incorporated; and it means that biodiversity at finer and coarser scales can be used as merited. This last property is particularly intriguing as it steps us ever closer to cross-scale analyses that encapsulate the true dynamism of the biogeographical processes that shape life on Earth. Spatial phylogenetics, then, is an exciting, modern, synthetic ‘big data’ approach to biogeography, benefitting from the rapid accumulation of genetic and geographical data in multiple databases over the past 1–2 decades (Mishler, 2023). That brings us back to the problem identified by Farquhar et al. (2022)—that a persistent challenge in biogeography has been obtaining sufficient data to study patterns in detail—but with a twist: while biogeographical data are now rapidly increasing in availability, sources, and types and facilitating new perspectives (e.g., Han et al., 2023), with big data come potentially big problems such as systematic biases in missing data or data types, data quality, and inference (Mishler, 2023). These are problems that will require analytical and philosophical discussions, about new concepts, methodologies and tools that allow us to see the world in different ways (e.g. Quinn, 2021). In Reshaping Biogeography, we will bring more of these scientific ‘standpoints’ to biogeography in the remainder of this anniversary year. For example, in coming issues, Ariza et al. (2023) will propose marine biogeographical divisions based on acoustic mapping; Grattarola et al. (2023) will explore how distinct sampling efforts across species' datasets can be reconciled in integrated species distribution models; Franklin (2023) will look to the past, present and future of species distribution modelling; and Ung & Buttigieg (2023) will develop an ontology for comparative biogeography. We look forward to these and additional topics—and your responses to them or additional ideas—in future issues of this special section and beyond. We thank Richard Ladle for his work as chief editor on the perspectives. Permits were not required for this article. The authors have no conflicts of interest. No data were involved in this publication. The authors are associate, chief and guest editors at Journal of Biogeography for the special section.