While the history of taxonomic diversification in open ocean lineages of ray-finned fish and elasmobranchs is increasingly known, the evolution of their roles within the open ocean ecosystem remains poorly understood. To assess the relative importance of these groups through time, we measured the accumulation rate of microfossil fish teeth and elasmobranch dermal denticles (ichthyoliths) in deep-sea sediment cores from the North and South Pacific gyres over the past 85 million years (Myr). We find...

The balance between natural selection, gene flow and genetic drift is difficult to resolve in marine invertebrates with extensive dispersal and fluctuating population sizes. The intertidal snail Chlorostoma funebralis has planktonic larvae and previous work using mtDNA polymorphism reported no genetic population structure. Nevertheless, recent studies have documented differences in thermal tolerance and transcriptomic responses to heat stress between northern and southern California, USA, populations. To gain insight into the dynamics influencing adaptive divergence, we...

The influence of decreasing Arctic sea ice on net primary production (NPP) in the Arctic Ocean has been considered in multiple publications but is not well constrained owing to the potentially large errors in satellite algorithms. In particular, the Arctic Ocean is rich in coloured dissolved organic matter (CDOM) that interferes in the detection of chlorophyll a concentration of the standard algorithm, which is the primary input to NPP models. We used the quasi-analytic algorithm...

An audience can have a profound effect on the dynamics of communicative interactions. As a result, non-human primates often adjust their social decision-making strategies depending on the audience composition at a given time. Here we sought to test how the unique vocal behaviour of multiple audience members affected decisions to communicate. To address this issue, we developed a novel experimental paradigm in which common marmosets directly interacted with multiple ‘virtual monkeys’ (VMs), each of whom...

Pollinators such as bees provide a critical ecosystem service that can be impaired by information about predation. We provide the first evidence for olfactory eavesdropping and avoidance of heterospecific alarm signals, alarm pheromones, at food sources in bees. We predicted that foragers would eavesdrop upon heterospecific alarm pheromones, and would detect and avoid conspicuous individual pheromone compounds, defined by abundance and how long they can linger to provide warning information (volatility). We show that Apis...

The surface energy is a fundamental property of the different facets of a crystal that is crucial to the understanding of various phenomena like surface segregation, roughening, catalytic activity, and the crystal’s equilibrium shape. Such surface phenomena are especially important at the nanoscale, where the large surface area to volume ratios leads to properties that are significantly different from the bulk. In this work, we present the largest database of the calculated surface energies of...

In colonial organisms, alarm pheromones can provide a key fitness advantage by enhancing colony defense and warning of danger. Learning which species use alarm pheromone and the key compounds involved therefore enhances our understanding of how this important signal has evolved. However, our knowledge of alarm pheromones is more limited in the social wasps and hornets as compared to the social bees and ants. Vespa velutina is an economically important and widespread hornet predator that...

Understanding the conditions that allow speciation to occur is difficult because most research has focused on either long-lived organisms or asexual microorganisms. We propagated bacteriophage λ, a virus with rapid generations and frequent recombination, on two Escherichia coli host genotypes that expressed either the LamB or OmpF receptor. When supplied with either single host (allopatry), λ improved its binding to the available receptor while losing its ability to use the alternative. When evolving on both...

The origin of new and complex structures and functions is fundamental for shaping the diversity of life. Such key innovations are rare because they require multiple interacting changes. We sought to understand how the adaptive landscape led to an innovation whereby bacteriophage λ evolved the new ability to exploit a receptor, OmpF, on Escherichia coli cells. Previous work showed that this ability evolved repeatedly, despite requiring four mutations in one virus gene. Here, we examine...

Collective behavior emerges from interactions among group members who often vary in their behavior. The presence of just one or a few keystone individuals, such as leaders or tutors, may have a large effect on collective outcomes. These individuals can catalyze behavioral changes in other group members, thus altering group composition and collective behavior. The influence of keystone individuals on group function may lead to trade-offs between ecological situations, because the behavioral composition they facilitate...

This study investigated the systematics of the Nearctic shield-back katydids (“Tettigoniinae”), a paraphyletic group thought to include genera from a distinctive Gondwanan tribe, the Nedubini, among an otherwise Holarctic fauna. From exemplars of five genera of Nedubini and the majority of other genera of Nearctic “Tettigoniinae,” five gene regions were sequenced, aligned with publicly available sequence data that represent diverse subfamilies of Tettigoniidae, and subjected to phylogenetic analysis under Bayesian and likelihood criteria. Our results...

Theory predicts that social interactions are dynamically linked to phenotype. Yet because social interactions are difficult to quantify, little is known about the precise details on how interactivity is linked to phenotype. Here, we deployed proximity loggers on North American barn swallows (Hirundo rustica erythrogaster) to examine intercorrelations among social interactions, morphology and features of the phenotype that are sensitive to the social context: stress-induced corticosterone (CORT) and gut microbial diversity. We analysed relationships at...

Monodehydroascorbate reductase (MDHAR; EC 1.6.5.4) is an important enzyme for ascorbate recycling. To examine whether heterologous expression of MDHAR from Oryza sativa (OsMDHAR) can prevent the deleterious effects of unfavorable growth conditions, we constructed a transgenic yeast strain harboring a recombinant plasmid carrying OsMDHAR (p426GPD::OsMDHAR). OsMDHAR-expressing yeast cells displayed enhanced tolerance to hydrogen peroxide by maintaining redox homoeostasis, proteostasis, and the ascorbate (AsA)-like pool following the accumulation of antioxidant enzymes and molecules, metabolic enzymes, and...

Differentiating the ability from the motivation to act is of central importance to psychiatric disorders in general and depression in particular. However, it has been difficult to develop quantitative approaches to relate depression to poor motor performance in goal-directed tasks. Here, we use an inverse optimal control approach to provide a computational framework that can be used to infer and factorize performance deficits into three components: sensorimotor speed, goal setting and motivation. Using a novel...