Abstract Many species have spread towards cooler climates and/or went extinct at the warm margin of their range as a result of climate warming. The large diversity in observed range shifts however remains poorly understood. We here explore how evolution of the climatic niche at range margins may alter range shifts patterns. We use previously developed mathematical results to predict the velocity at which rear and leading edge move in an asexual species adapting to an environment that changes in space and time. As in previous studies, we find a critical climate change velocity beyond which the species cannot persist. We further predict the critical climate velocities, below which, the leading edge shifts faster than climate, or the species persists at its rear edge. We derive predictions along one-dimensional and two-dimensional ranges. We also examine the effect of a local disturbance on the velocity of range limits. Our simple mathematical model shows that evolution of species climatic niches at range margins can already generate a large diversity of types of range shift in a warming climate. This diversity is also observed in simulations assuming sexual reproduction or finite population sizes. The expectation of a simple climate tracking may therefore be too simplistic, underestimating the resilience capacity at the warm margins and either overestimating or underestimating the capacity for spread at the cold margin, with important consequences for management of biodiversity in a changing climate.
Evolutionary trajectories are determined by selection and the underlying genetic architecture of additive genetic variances and covariances for the traits. To better understand divergence in multivariate phenotypes among natural populations, we need population-specific estimates of selection and genetic architecture of the traits involved; such extensive data are challenging to acquire and few examples exist. Here we do this using males from six populations of the mushroom-feeding fly Drosophila subquinaria. We take advantage of a naturally occurring pattern of reproductive character displacement involving male chemical display traits (cuticular hydrocarbons/CHCs) between populations that are sympatric vs. allopatric with the closely related Drosophila recens. Genetic (co)variance structures for male CHCs from three populations from each region were previously quantified; here we provide novel estimates of sexual selection on these traits within each population and quantify the extent to which this differs between regions. Then, using all these data we implement a comparative approach investigating how differences in sexual selection and genetic architecture can explain the observed pattern of CHC divergence, extending the method beyond past applications to incorporate uncertainty in estimates of selection and genetic (co)variances. We find modest differences in sexual selection between regions, in contrast to past studies, and that divergence is not well explained by this alone. However, explanatory ability improves substantially when genetic (co)variances among the traits are accounted for. We also find that predicted evolutionary responses to sexual selection in sympatry are likely constrained as the genetic "line of least resistance" is not well aligned with selection.
Abstract Cancer comprises a group of diseases characterised by the uncontrolled proliferation of abnormal somatic cells in the body. It is considered a major health challenge in humans, and its global burden is projected to increase in the coming decades. However, cancer is not unique to humans, and it is hypothesised to have appeared alongside multicellularity. Therefore, it should be discussed and studied as an inherent pathology for all multicellular organisms. Guided by this evolutionary perspective, we highlight key research avenues through which marine ecosystems could improve our understanding of cancer biology and support the development of improved prevention and therapeutic strategies. In particular, marine ecosystems (1) harbour animals with some of the most extreme life history traits, thereby highlighting how natural cancer suppression might have evolved; (2) harbour animals exposed to some of the strongest oncogenic environmental contaminations, thereby providing natural systems to investigate how pre-existing anticancer mechanisms shape cancer susceptibility, and (3) harbour the most diverse set of transmissible cancers in marine bivalves, allowing us to explore mechanisms underlying inter-individual differences in resistance and disease spread within and between populations. These systems provide unique opportunities to uncover how cancer resistance evolves across deep evolutionary timescales. They also present opportunities to investigate naturally evolved anticancer mechanisms and bioactive compounds that could inspire biomimetic approaches to cancer prevention and therapy. By integrating evolutionary biology, marine ecology, and oncology, marine systems could become a powerful frontier for discovering fundamental principles of cancer resistance and exploring their potential relevance for biomedical innovations.
Abstract Symbiotic associations between microorganisms and hosts are universal, diverse, and dynamic. Yet, our ability to represent this complexity mathematically remains limited. We propose extending consumer–resource theory to incorporate evolutionary processes to advance our understanding of symbioses, from pairwise interactions to complex host–microbe assemblages. The resulting eco-evolutionary framework captures feedbacks between host–microbe interaction structure, biotic resource availability, and selection acting across biological scales. Importantly, this approach relaxes the assumption of separated ecological and evolutionary timescales so that both processes unfold simultaneously. The coupling between ecological and evolutionary dynamics allows key properties of symbioses, such as ecological dependence and functional integration, to emerge from evolving resource-mediated interactions, rather than being imposed a priori. We illustrate the framework with a mathematical model of mycorrhizal symbiosis. The proposed consumer–resource formulation provides a unified basis for linking ecological and evolutionary dynamics in host–microbe symbioses, with implications for both basic theory and applied management.
Abstract Identifying the determinants that shape the duration and timing of avian moult is essential for understanding the evolution of moulting strategies and predicting life-cycle responses to ongoing environmental change. Although body size, migration distance, and breeding latitude have been proposed to explain interspecific variation in the annual complete moult among songbirds, breeding duration remains largely unexplored, and these factors have rarely been evaluated jointly within a phylogenetic comparative framework. We combined these four predictors in phylogenetically informed models to assess their effects on complete moult duration and timing across European passerines. Phylogenetic relationships did not explain variation in moult duration. Instead, migration distance, body mass, and breeding latitude had independent effects on summer moult duration. After accounting for these variables, species with longer breeding periods exhibited shorter moults. In contrast, moult timing was partially explained by phylogenetic structure, with no detectable effects of continuous predictors. These contrasting patterns suggest that the drivers of variation in moult duration and timing might differ. Contrary to previous parsimony-based reconstructions, maximum likelihood ancestral state reconstruction inferred winter moult as the ancestral state and detected relatively few transitions to summer moult, likely limiting statistical power to detect ecological effects on moult timing. Overall, our results provide a comparative assessment of the determinants of summer moult duration in European passerines and preliminary support for winter moult as the ancestral state. Broader phylogenetic sampling is needed to further test this latter possibility, which, if confirmed, could prompt a reassessment of prevailing interpretations of moult timing evolution.
