Proceedings of the Royal Society B Biological Sciences

Abstract Fireflies (Lampyridae) represent the most diverse terrestrial group of organisms capable of bioluminescence. However, their evolution remains inadequately understood due to the scarcity of early fossils. In this study, we uncover a new fossil genus and species, Cretoluciola birmana gen. et sp. nov., derived from a high-quality piece of the mid-Cretaceous Burmese amber. This new taxon is …

Abstract Parental care typically protects offspring from environmental stress. Yet, it remains unclear whether this protection arises from stress effects on parents, offspring or their interactions. We addressed this gap in the European earwig (Forficula auricularia) by independently manipulating heat stress in mothers and eggs using a cross-fostering experiment and measuring maternal care and of…

Abstract Biodiversity assessments in remote ecosystems are often limited by the difficulty of detecting rare, cryptic or nocturnal species. Species distribution models (SDMs) are widely used to predict distributions, yet few studies validate them with independent field data. Converting continuous suitability maps into binary predictions through threshold selection remains controversial. Nearly 50…

Abstract Vertebrates are unique among animals as they bear a neurocranium, which almost completely encapsulates the brain. Thus, within vertebrates, the evolution of neuroanatomical features might be tightly correlated with the evolution of their surrounding neurocranial ossifications, as these pose spatial constraints to brain size and shape. The endocranial cast, or surrounding neurocranial oss…

Abstract Maternal stress and the developmental environment jointly affect offspring fitness and phenotype during early life. Mothers transmit stress to offspring through the deposition of hormones and energy into developing embryos, who are themselves subject to environmental stressors. A species’ life-history strategy (e.g. size and number of eggs) may further buffer or exacerbate the effects of…

Abstract Despite its detrimental effects, inbreeding depression in wild populations is relatively under-explored. Here, we use whole-genome sequence data from more than 2700 wild barn owls (Tyto alba) to investigate the presence, severity and genetic architecture of inbreeding depression in three morphological traits. Using linear models (accounting for age) and nonlinear models (measuring growth…

Abstract Population-level distributions of fluorescence or molecule counts are often taken to reflect the behaviours of individual cells within that population. In this conceptual article, I argue that counting subpopulations can be a misleading proxy for identifying the number of behavioural modes accessible to individual cells within a system. I show that definitions of behavioural modes based …

Abstract Host dispersal influences how frequently a parasite encounters new susceptible hosts, which translates into potential conflict between parasite and host interests regarding dispersal. In vertically transmitted parasites, the impact of host dispersal on parasite spread appears limited. Here, it is less intuitive whether parasites can benefit by manipulating host dispersal and, if so, whet…

Abstract Worldwide, humans have altered ecosystems not only by reducing and changing the distribution of resources but also by providing new foraging opportunities to wildlife. However, little is known about the early-life development and maintenance of new foraging behaviours, which are crucial for species to adapt to human-induced environmental changes. Using a longitudinal global positioning s…

Abstract Biogeography relies on estimates of phylogeny and gene flow to test hypotheses. Established theory posits: (i) gene flow varies non-randomly with respect to geography and (ii) gene flow can mislead phylogenetic inference. These findings, often viewed in isolation, together suggest that spatial impacts on gene flow could bias biogeographic inference. For example, whenever a ‘peripheral’ p…

Abstract Quantity discrimination is an important aspect of numerical cognition that is utilized across taxa in various ecological contexts, including foraging and predator avoidance. Recent research has identified that the developing young of several species possess spontaneous quantity discrimination abilities, though these are often limited compared with adults. These studies have been conducte…

Abstract Bacterial persister cells are characterized by arrested growth and survival in normally lethal antibiotic concentrations. Observations of persistence peaking in the stationary phase suggest that its function may be associated with slow growth, potentially acting as a ‘bet-hedging’ strategy under stress. However, fundamental questions remain about the adaptive function of persistence and …

Abstract Morphological disparity, reflecting the breadth of phenotypic variation within clades, offers critical insights into evolutionary dynamics beyond taxonomic diversity. Using a large discrete morphological character dataset, this study investigates disparity patterns in Elateriformia, a hyperdiverse beetle clade that includes click beetles, jewel beetles and their relatives, to explore mac…

Abstract Over 230 million years of Earth’s history, dinosaurs became a major terrestrial animal clade and produced one of the most species-rich living tetrapod lineages: birds. Yet, largely because of uncertainty surrounding the phylogeny of early dinosaurs, the tempo and mode of their emergence and initial radiation remain poorly constrained. Here, we reconstruct the initial diversification of d…

Abstract Population-scale long-read DNA sequencing (PLRS) is rapidly reshaping our understanding of genomic variation in humans and non-model species. In this Darwin Review, we first recount the expansion of the PLRS concept and its twin paradigm, the pangenome, over the past 20 years, emphasizing recent results from non-human vertebrates. Using recent PLRS studies in birds as test cases, we prob…

Abstract The gaits of bipedal and quadrupedal animals are well characterized, while, with few naturally occurring tripedal gaits, little is understood regarding locomotion on three legs. Canine amputees provide a unique perturbation into the study of locomotion. This study assesses whether these individuals use distinct limb sequences, with clearly defined kinematics and kinetics, which could be …

Abstract Characterizing how biodiversity has changed through Earth’s history and uncovering the processes that have driven those changes remain a significant challenge. Haar fluctuation analysis, a recently developed time-series method, has been suggested as a powerful new tool to infer macroevolutionary drivers and assess system stability. Yet the ability of this method to identify unique driver…

Abstract Environmental perturbations often lead to the evolution of multiple traits. Determining whether shared genetic factors underlie multi-trait evolution is a central question in evolutionary biology. In the Mexican tetra, Astyanax mexicanus, cave-dwelling populations have repeatedly evolved multiple traits. The repeated evolution of these traits, paired with robust environmental differences…

Abstract Across cultures, people have long sung while working together—yet potential functional benefits of singing work songs have rarely been investigated experimentally. Rhythmic joint actions such as rowing, hammering or clapping tend to accelerate over time, a phenomenon known as joint rushing, which can undermine coordinated joint performance. Here, we examine whether features typical of tr…

Abstract Understanding the mechanisms underlying animal cognition requires experimental designs and analyses that respect the biological and perceptual constraints of the species being studied. We address an ongoing debate regarding the role of visual spatial frequency in numerical cognition studies, using honeybees (Apis mellifera) as a model system. Prior analyses that excluded the low spatial …