Lesley T. Lancaster

Rapid environmental change poses unprecedented challenges for species persistence, threatening not only population size but the genomic adaptive variation required for evolutionary responses. Understanding this adaptive potential is crucial for effective management and conservation strategies, as it determines a population's capacity to cope with current and future climate shifts, habitat loss, emerging diseases and other environmental pressures. This Special Issue is therefore timely in the context of advancing genetic diversity monitoring recommendations (e.g., UN Convention on Biological Diversity Target 4), bringing together 40 original papers, perspectives and reviews that link genomic insights to conservation status and practice. The contributions span empirical studies, mechanistic investigations, theoretical frameworks and applied case studies. Together, these studies highlight how genomic approaches can illuminate the mechanisms and distribution of adaptive variation and inform strategies to maintain population resilience and guide effective management under environmental change.

Climate change influences the physiology and population dynamics of ectothermic pests, with major repercussions for global crop production. Yet, how evolution modulates these outcomes remains unclear. We exposed the widespread beetle pest Callosobruchus maculatus to 10 years of experimental evolution at different temperatures and quantified thermal responses of life-history traits. Hot- and cold-adapted populations evolved differences in thermal sensitivity, but these were modest relative to evolved differences in trait averages. By leveraging high-resolution temperature time-series we show that the observed evolution translates into cold-adapted genotypes having highest fitness in cold climates and hot-adapted genotypes in warm climates. Hot-adapted beetles maximize fitness in warm climates by increased larval growth, resulting in larger body sizes and higher fecundity. This evolutionary strategy compounds projected crop losses under warming by increasing both intrinsic population growth and per-capita host consumption rates. By year 2100 under intermediate-to-high warming (SSP3-7.0), pest evolution is projected to increase global crop damage potential by +113% from present—twice that expected from warming alone (not accounting for evolution). In major crop-producing areas, where temperatures and the beetles’ host consumption rates are already high, warming increases average crop damage potential by +29%, but evolution amplifies this three-fold to +87%. Evolution also expands C. maculatus ’ projected colonizable range and in some regions even flips forecasted crop damage reductions into increases. These results identify climate-driven evolution of pest life-histories as an amplifier of agricultural losses and suggest that current projections may significantly understate the threat warming poses to future food security.

There is a growing interest in the genomic and developmental basis of discrete or multimodal phenotypes governed by genetic polymorphisms. Recent research has uncovered the genomic basis of such polymorphisms and their maintenance through balancing selection such as negative frequency-dependent selection (NFDS). Such polymorphisms often originate through structural genomic changes or through mutations in regulatory genes. Historically, researchers focused on male-limited polymorphisms and intrasexual competition as drivers of NFDS. However, an increasing number of female-limited polymorphisms are being discovered, with sexual conflict, social selection or natural selection maintaining such polymorphisms. Still, significant gaps in our understanding of female-limited polymorphisms linger, partly as a historical legacy of a male-centric research focus on conspicuous male phenotypes. We review and synthesize female-limited polymorphisms, their maintenance, genetic architecture, genomic basis, developmental origin, microevolutionary dynamics and macroevolutionary diversification. Animals with female-limited polymorphisms include invertebrates (e.g. bedbugs, butterflies, damselflies and fruit flies) but also vertebrates (e.g. birds, mammals and reptiles). By highlighting female-limited polymorphisms, we draw attention to the unique sex-specific selection pressures on females distinguishing them from male-limited polymorphisms. Finally, wee present a conceptual model aimed to explain the origin and evolution of female-limited polymorphisms and outline future research avenues in this emerging field. This article is part of the theme issue ‘Exploring negative frequency dependent selection across levels: from genetics to ecology and back again’.

When predicting species’ responses to changing environments, one can use mathematical functions that describe how individual fitness components depend on the environment, or a single “composite” function that directly links fitness to the environmental state. The former approach is a cornerstone of process-based modelling, but the latter remains standard for developing fundamental theory and making ecological predictions. Yet, fitness is not a single instantaneous trait, but an integrated outcome of multiple underlying processes accruing throughout an organism’s life. We show that by ignoring the distinct environmental dependence of the underlying processes, predictions from composite fitness functions become inherently flawed in variable environments. We explore the magnitude of this error by leveraging empirical thermal reaction norms for four important life-history processes in an insect pest, the seed beetle Callosobruchus maculatus . We parameterize two fitness functions: one explicitly modelling the temperature-dependence of the four life-history traits independently (the “ground truth”) and one composite function, which treats fitness as a single, instantaneous outcome of the environment. By combining these two functions with hourly temperature data, we projected demographic responses under different warming scenarios across 300 sites over three beetle population origins (California, USA; Yemen; Brazil). We show that the composite function over- or underestimates fitness depending on subtle climatic differences and whether fitness is assumed to accumulate additively or multiplicatively, highlighting the problems of applying composite fitness functions to variable conditions. We conclude that explicitly modeling trait-specific processes will become increasingly important for accurate eco-evolutionary forecasting under future environmental change.

Anticipating how species distributions will shift with climate change is key for biodiversity conservation and management. Commonly, species’ range shifts are observed by analyzing changes in occurrence or abundance data through time, or predicted across different climate change scenarios by modeling species’ climatic niches. However, it remains unclear how well these climate-based forecasts align with empirically documented range shifts from monitoring efforts. Here, we tested the congruence between modeled range shifts, predicted using climatic niche models, and documented range shifts, derived from empirical observations collected over recent decades, for more than 9,500 range shifts across over 3,500 marine and terrestrial species. We found that documented and modeled range shifts tend to align in latitudinal direction, with greater alignment for marine (76%) than terrestrial (56%) cases. However, even when the directions aligned, documented shifts exceeded modeled shifts in 62% of cases, nearly twice as often as they lagged behind (38%), and their median rates were four times faster than those of the modeled shifts. Our findings suggest that climate-based models can approximate observed range dynamics under specific conditions, particularly over long time periods and restricted spatial areas, when habitats remain well connected and under low climate fluctuations over time. These insights provide valuable guidance for both improving predictions and informing responses to climate-driven biodiversity redistribution.

Climate change threatens biodiversity when species cannot tolerate, adapt to, or track shifting environmental conditions to stay within their climatic niches. A major unresolved question is whether and how species' genetic diversity modulates these dynamics, buffering against range contractions or facilitating range expansions. To test this, we integrated the largest global databases of species range shifts and genetic diversity, encompassing 4673 range shift estimates for 1888 species with available genetic data, including insects, arachnids, birds, fish, and plants. We found that range shifting rates were significantly shaped by the interaction of genetic diversity and climate change velocity. Under rapid warming, species with higher genetic diversity exhibited reduced trailing edge contractions, likely reflecting enhanced evolutionary potential or reduced vulnerability to drift. Under moderate warming, species with higher genetic diversity shifted more rapidly at leading edges and range centroids, consistent with greater colonisation ability. Our study provides evidence that genetic diversity potentially enables persistence at the trailing edge and colonisation at the leading edge, with the magnitude of these effects varying depending on the velocity of climate change.

Heatwaves are set to become more common due to climate change, and the potential of heatwaves to damage a species' populations is becoming more apparent. One way heatwaves can affect reproduction is by changing the dynamics of precopulatory mating behaviours, which can detrimentally impact individuals' survival and reproductive success. However, little work has been done to investigate how different levels of intrasexual and intersexual selection in precopulatory behaviours, such as male–male competition or female‐mate choice, modulate fitness responses to heatwave. Here we investigate how differing levels of male competition and female choice impact survival and reproductive success when a heatwave event occurs, using cool‐adapted Scottish populations of the burying beetle Nicrophorus vespilloides as a model system. We implemented three treatments for precopulatory conditions: monogamy (one male, one female, no male–male competition), polyandry with male competition (one female, two males, where males and females could freely interact), and polyandry with low male competition (one female, two males, where males could not interact with each other or the female freely). We then subjected the beetles to a heatwave event (3 days at 25°C) at the time of mating. We found that reproductive fitness decreased under a heatwave in the polyandry/low male competition treatment, compared to both the monogamy and the male competition treatments. Our results indicate that differing levels of intrasexual and intersexual selection can moderate the detrimental effects of heatwaves in wild species.

Amidst increasing reports of insect declines, it is ever more important to understand spatial and temporal insect diversity patterns and processes. Phylogenetic diversity ( PD ) is an important biodiversity metric in that it relates strongly to ecosystem processes, and it can be estimated more accurately from opportunistic occurrence data than other elements of biodiversity. Here, we assess recent changes across global variation in Lepidopteran PD , to discover overall patterns, their repeatability across regions and environmental drivers. We assess global, spatiotemporal variation in PD , as compared to null expectations given sampling effort, determining how such variation relates to region, space, time and environment. Our analysis is based on 374,749 gene sequence accessions from the barcode of life database ( BOLD ), representing 3158 species assemblages, spanning 62 years. We find that global variation in PD of Lepidopteran species assemblages has significantly increased over time at high latitudes while remaining relatively unchanged near the equator. This pattern exhibits parallelism across global regions, with the strongest increases in PD towards the present observed in high‐latitude communities in North America and Asia, in lowland sites in Europe, and across the African continent. In contrast, PD has declined through time in wetter portions of Australasia and in Africa and South America. Our reported patterns likely reflect changes in Lepidopteran responses to tropical habitat loss and widespread range expansions to higher latitudes. However, changing clines in DNA barcoding strategies could also play a role. Detecting spatiotemporal patterns of change in PD at the global scale is enabled by the increasing use of genetic markers in taxonomy. Our replicated findings provide confidence in biogeographic interpretation, yet increased metadata on sub‐sampling decisions would aid future interpretation of biodiversity trends using ecological genomics synthesis.

Novel competitive interactions between native and range shifting species can precipitate local extinction of native species. However, increased biological complexity within recipient communities may prevent native species loss by decreasing the strength of novel competition experienced by any one species. This phenomenon, termed ‘biotic resistance’, is commonly applied in invasion ecology, but has received little attention in the context of climate induced range shifts. Here we investigate the effects of biotic resistance in competition between resident native and range‐shifting damselflies in a region of Scotland newly colonised by the range‐shifter, using competitive mesocosm treatments across multiple life stages and experimental temperatures. Our focal native species (Lestes sponsa) was unaffected by increasing competitive complexity as larvae, showing no fitness benefits in multispecies treatments compared to intraspecific or even interspecific scenarios in the presence of the range shifter. However, multispecies competition with both native and range‐shifting species improved adult survival of our focal native species at higher temperatures, compared to interspecific competition with just the range shifter. For our focal range‐shifting species (Ischnura elegans), larval growth rate was significantly reduced in multispecies treatments compared to intraspecific or two‐species interspecific scenarios, yet adult range shifter survival showed no decrease in multispecies treatments. Furthermore, range shifter larvae displayed improved survival and growth in colder temperatures, compared to a lack of any temperature effects on adult survival. These results suggest that biotic resistance may alleviate the competitive impacts of range shifters on native communities by providing a life stage‐dependent benefit to native species while simultaneously decreasing the fitness of range shifters. However, shifting temperatures can cause this interaction to swap between competition and facilitation, creating an environmentally dependent scenario that may benefit both range shifters and resident species, promoting the maintenance of diversity in high latitude communities.

Plant–pollinator interactions structure ecological communities and represent a key component of ecosystem functioning. Pollination networks are expected to be more diverse and specialised in the tropics, but pollination ecology in these regions has been understudied in comparison to other areas. We reviewed research on pollination in the tropical Andes, one of the major biodiversity hotspots on Earth, where the uplift of mountains and past climate have resulted in spatiotemporally distinct species interactions. We found 1010 scientific articles on pollination in the Andes, of which 473 included or were carried out in tropical regions. The number of publications on pollination ecology in the tropical Andes has increased exponentially, with Colombia having the most articles, followed by Ecuador and Peru, and with Bolivia and Venezuela having notably fewer studies. More research has been carried out in humid montane forests and agricultural landscapes, and it has predominantly focused on describing diversity of species and interactions while neglecting analyses on the resilience and adaptability of pollinating systems, even though the Andean region is particularly susceptible to the effects of climate change and continues to undergo land conversion and degradation. Remarkably few studies have incorporated local knowledge, thus ignoring connections to human livelihoods and communities. A phytocentric perspective has been predominant, with fewer studies focusing directly on pollinators and a notable lack of articles with a holistic approach to the study of pollination across taxonomic groups at the community or ecosystem level. We propose that future research adopts a cross‐scale approach that considers the complexity of the ecological contexts in which plant–pollinator interactions occur, and incorporates long‐term monitoring with broader multilayer networks and molecular tools, experiments focused on ecophysiology and behaviour, animal telemetry, process‐modelling approaches and participatory science. A stronger field driven by interdisciplinary collaborations will contribute to knowledge about pollination at a global scale, as well as increase our understanding of the diversity and resilience of pollination interactions in this region, thus improving our capacity to predict and avoid ecosystem collapses.