The many high-resolution tools that are uniquely applicable to specimens from the Quaternary period (the past ~2.5 Ma) provide an opportunity to cross-validate data and test hypotheses based on the morphology and distribution of fossils. Among these tools is palaeogenomics – the genome-scale sequencing of genetic material from ancient specimens – that can provide direct insight into ecology and evolution

Classic models for the development and evolution of ant castes struggle to explain recent empirical results. Here, we propose an hourglass model compatible with all existing data, providing a formal, falsifiable framework for future study. This illustrates how phenotypic variation can be used to infer underlying developmental and genetic architecture.

The global carbon cycle connects organic matter (OM) pools in soil, freshwater, and marine ecosystems with the atmosphere, thereby regulating their size and reactivity. Due to the complexity of biogeochemical processes and historically compartmentalized disciplines, ecosystem-specific conceptualizations of OM degradation have emerged independently of developments in other ecosystems. Recent discussions

Many ecological and evolutionary processes are affected by urbanization, but cities vary by orders of magnitude in their human population size and areal extent. To quantify and manage urban biodiversity, one must understand both how biodiversity scales with city size, and how ecological, evolutionary, and socioeconomic drivers of biodiversity scale with city size. We show how environmental abiotic

Central theories explaining the maintenance of individual differences in behavior build on the assumption that behavior mediates life-history trade-offs between current and future reproduction. However, current empirical evidence does not robustly support this assumption. This mismatch might be because current theory is not clear about the role of behavior in individual allocation versus acquisition

Research on how competitors assess (i.e., gather information on) fighting ability and contested resources, as well as how assessment impacts on contest processes and outcomes, has been fundamental to the field of dyadic (one-on-one) contests. Despite recent growth in studies of contests between social-living groups, there is limited understanding of assessment during these intergroup contests. We adapt

Biologists have long appreciated the critical role that energy turnover plays in understanding variation in performance and fitness among individuals. Whole-organism metabolic studies have provided key insights into fundamental ecological and evolutionary processes. However, constraints operating at subcellular levels, such as those operating within the mitochondria, can also play important roles in

Non-human primates are among the most vulnerable tropical animals to extinction and ~50% of primate species are endangered. Human hunting is considered a major cause of increasingly ‘empty forests’, yet archaeological data remains under-utilised in testing this assertion over the longer-term. Zooarchaeological datasets allow investigation of human exploitation of primates and the reconstruction of

Most animals have complex life cycles including metamorphosis or other discrete life stage transitions, during which individuals may be particularly vulnerable to environmental stressors. With climate change, individuals will be exposed to increasing thermal and hydrologic variability during metamorphosis, which may affect survival and performance through physiological, behavioral, and ecological mechanisms

Since Darwin, individuals and more recently genes, have been the focus of evolutionary thinking. The idea that selection operates on nonreproducing, higher-level systems including ecosystems or societies, has met with scepticism. But research emphasising that natural selection can be based solely on differential persistence invites reconsideration of their evolution. Self-perpetuating feedback cycles

Science textbooks communicate fundamental discoveries and serve as platforms showcasing role models for students. However, the scientists represented across undergraduate textbooks do not reflect the demographic makeup of the student population reading those materials. We recommend a series of changes within curricula to challenge the stereotypical identity of science.

Transfer efficiency is the proportion of energy passed between nodes in food webs. It is an emergent, unitless property that is difficult to measure, and responds dynamically to environmental and ecosystem changes. Because the consequences of changes in transfer efficiency compound through ecosystems, slight variations can have large effects on food availability for top predators. Here, we review the

We present the results from our 12th annual horizon scan of issues likely to impact biological conservation in the future. From a list of 97 topics, our global panel of 25 scientists and practitioners identified the top 15 issues that we believe society may urgently need to address. These issues are either novel in the biological conservation sector or represent a substantial positive or negative step-change

Lockdown measures fundamentally reshaped human society during the COVID-19 pandemic. We present a framework featuring seven animal behavioral changes to the calming effect of the lockdowns on human actions (COVID-19 quietus). We demonstrate how this framework can be used to quantify animal behavioral responses with implications for ecology and conservation.

Speciation is frequently initiated but rarely completed, a phenomenon hypothesized to arise due to the failure of nascent lineages to persist. Although a failure to persist often has ecological causes, key gaps exist between ecological and evolutionary theories that, if filled, would clarify when and why speciation succeeds or fails. Here, we apply ecological coexistence theory to show how the alignment

Current narratives suggest that urban adaptation – the adaptive evolution of organisms to cities – is pervasive across taxa and cities. However, in reviewing hundreds of studies, we find only six comprehensive examples of species adaptively evolving to urbanization. We discuss the utility and shortcomings of methods for studying urban adaptation. We then review diverse systems offering preliminary

The origin and zoonotic transmission route of SARS-CoV-2 remains speculative. Here we discuss scenarios for the zoonotic emergence of SARS-CoV-2, along with exploring missing evidence and ecological considerations that are required to confidently identify the origin and transmission route of SARS-CoV-2 and to prevent future pandemics of zoonotic viruses.

Humanity’s impact on the environment is increasing, as are strategies to conserve biodiversity, but a lack of understanding about how interventions affect ecological and conservation outcomes hampers decision-making. Time series are often used to assess impacts, but ecologists tend to compare average values from before to after an impact; overlooking the potential for the intervention to elicit a change

Given the failure of the world’s governments to improve the status of biodiversity by 2020, a new strategic plan for 2030 is being developed. In order to be successful, a step-change is needed to not just simply halt biodiversity loss, but to bend the curve of biodiversity loss to stable or increasing species’ populations. Here, we propose a framework that quantifies species’ responses across gradients

Resource tracking, where animals increase energy gain by moving to track phenological variation in resources across space, is emerging as a fundamental attribute of animal movement ecology. However, a theoretical framework to understand when and where resource tracking should occur, and how resource tracking should lead to emergent ecological patterns, is lacking. We present a framework that unites

Ecological release, originally conceived as niche expansion following a reduction in interspecific competition, may prompt invasion success, morphological evolution, speciation, and other ecological and evolutionary outcomes. However, the concept has not been recently reviewed. Here, we trace the study of ‘ecological release’ from its inception through the present day and find that current definitions

Growing demand for tropical commodities that are socially and environmentally more sustainable is changing the global market for agroforestry products such as coffee and cocoa. Transforming mass production of cash crops towards higher socio-ecological standards includes challenges, but also novel opportunities to protect ecosystem services and human health and well-being alike.

Zoonosis-based epidemics are inevitable unless we revisit our relationship with the natural world, protect habitats, and regulate wildlife trade, including live animals and non-sustenance products. To prevent future zoonoses, governments must establish effective legislation addressing wildlife trade, protection of habitats, and reduction of the wildlife–livestock–human interface.

Most efforts to predict novel reservoirs of zoonotic pathogens use information about host exposure and infection rather than competence, defined as the ability to transmit pathogens. Better obtaining and integrating competence data into statistical models as covariates, as the response variable, and through postmodel validation should improve predictive research.

Extreme climatic events cause devastating impacts to species and ecosystems, precipitating significant mortality. However, emerging empirical evidence is revealing that such mortality can drive directional selection and result in increased tolerance. We discuss the novel opportunities for promoting climate resilience presented by this ‘silver lining’ of extreme events.

Understanding how the three currencies of life – energy, material, and information – interact is a key step towards synthesis in ecology and evolution. However, current theory focuses on the role of matter as a resource and energy, and typically ignores how the same matter can have other important effects as a carrier of information or modifier of the environment. Here we present the hypothesis that

Understanding the evolutionary and ecological roles of 'non-genetic' inheritance (NGI) is daunting due to the complexity and diversity of epigenetic mechanisms. We draw on insights from molecular and evolutionary biology perspectives to identify three general features of 'non-genetic' inheritance systems: (i) they are functionally interdependent with, rather than separate from, DNA sequence; (ii) precise

Understanding ecological processes and predicting long-term dynamics are ongoing challenges in ecology. To address these challenges, we suggest an approach combining mathematical analyses and Bayesian hierarchical statistical modeling with diverse data sources. Novel mathematical analysis of ecological dynamics permits a process-based understanding of conditions under which systems approach equilibrium

Plant growth is usually constrained by the availability of nutrients, water, or temperature, rather than photosynthetic carbon (C) fixation. Under these conditions leaf growth is curtailed more than C fixation, and the surplus photosynthates are exported from the leaf. In plants limited by nitrogen (N) or phosphorus (P), photosynthates are converted into sugars and secondary metabolites. Some surplus

We are facing a biodiversity crisis at the same time as we are acquiring an unprecedented view of the world’s biodiversity. Vast new datasets (e.g., species distributions, traits, phylogenies, and interaction networks) hold knowledge to better comprehend the depths of biodiversity change, reliably anticipate these changes, and inform conservation actions. To harness this information for conservation

Conservation and sustainable management activities are critical for enhancing ecosystem services. Systematic conservation planning (SCP) is a spatial decision support process used to identify the most cost-effective places for intervention and is increasingly incorporating ecosystem services thinking. Yet, there is no clear guidance on how to incorporate ecosystem service components (i.e., supply,

Signals reliably convey information to a receiver. To be reliable, differences between individuals in signal properties must be consistent and easily perceived and evaluated by receivers. Iridescent objects are often striking and vivid, but their appearance can change dramatically with viewing geometry and illumination. The changeable nature of iridescent surfaces creates a paradox: how can they be

Field courses have been identified as powerful tools for inclusion and student success in science. However, not all students are equally likely to take field courses. How do we remove barriers to equity in field courses, to make them engines for inclusion, diversity, and collective excellence in ecology and evolution?

Ruminant livestock are a significant contributor to global methane emissions. Infectious diseases have the potential to exacerbate these contributions by elevating methane outputs associated with animal production. With the increasing spread of many infectious diseases, the emergence of a vicious climate–livestock–disease cycle is a looming threat.

Plant domestication, at least in cereals, is associated with the loss of the shattering allele. In such species, grains are manually harvested and threshed, leaving behind naked seeds. This could have led to the loss of maternally borne seed microbiomes and their associated benefits in modern-day domesticated species.

Speciation is a fundamental process shaping biodiversity. However, existing empirical methods often cannot provide key genetic and functional details required to validate speciation theory. New gene modification technologies can verify the causal functionality of genes with astonishing accuracy, helping resolve questions about how reproductive isolation evolves during speciation.

Managing vertebrate pests is a global conservation challenge given their undesirable socio-ecological impacts. Pest management often focuses on the ‘average’ individual, neglecting individual-level behavioural variation (‘personalities’) and differences in life histories. These differences affect pest impacts and modify attraction to, or avoidance of, sensory cues. Strategies targeting the average

Without changes in consumption, along with sharp reductions in food waste and postharvest losses, agricultural production must grow to meet future food demands. The variety of concepts and policies relating to yield increases fail to integrate an important constituent of production and human nutrition – biodiversity. We develop an analytical framework to unpack this biodiversity-production mutualism

Barriers to gene flow between divergent populations result in contact (hybrid) zones. Locations where multiple contact zones overlap can be used in comparative studies asking: what mechanisms maintain barriers; what is the origin of the genetic variation involved; and do differences in life history affect the nature of barriers? In a review of 23 marine species’ genetic divergence over a postglacial

Many organisms are accumulating climatic debt as they respond more slowly than expected to rising global temperatures, leading to disequilibrium of species diversity with contemporary climate. The resulting transient dynamics are complex and may cause overoptimistic biodiversity assessments. We propose a simple budget framework to integrate climatic debt with two classes of intervention: (i) climatic

Carrying capacity is a key concept in ecology. A body of theory, based on the logistic equation, has extended predictions of carrying capacity to spatially distributed, dispersing populations. However, this theory has only recently been tested empirically. The experimental results disagree with some theoretical predictions of when they are extended to a population dispersing randomly in a two-patch

Half a century ago, Janzen and Connell hypothesized that the high tree species diversity in tropical forests is maintained by specialized natural enemies. Along with other mechanisms, these can cause conspecific negative density dependence (CNDD) and thus maintain species diversity. Numerous studies have measured proxies of CNDD worldwide, but doubt about its relative importance remains. We find ample

Recent renewed interest in using fossil data to understand how biotic interactions have shaped the evolution of life is challenging the widely held assumption that long-term climate changes are the primary drivers of biodiversity change. New approaches go beyond traditional richness and co-occurrence studies to explicitly model biotic interactions using data on fossil and modern biodiversity. Important

All organisms have a stress response system to cope with environmental threats, yet its precise form varies hugely within and across individuals, populations, and species. While the physiological mechanisms are increasingly understood, how stress responses have evolved remains elusive. Here, we show that important insights can be gained from models that incorporate physiological mechanisms within an

Climate change and land use change often interact, altering biodiversity in unexpected ways. Research into climate change–land use change (CC–LUC) interactions has so far focused on quantifying biodiversity outcomes, rather than identifying the underlying ecological mechanisms, making it difficult to predict interactions and design appropriate conservation responses. We propose a risk-based framework

Social information and socially transmitted pathogens are governed by social structure, and also shape social interactions. However, information and infection are rarely investigated as interactive factors driving social evolution. We propose exactly such an integrative framework, drawing attention to mechanisms of social phenotypic plasticity for information spread and pathogen control.

Scientific misconceptions are likely leading to miscalculations of the environmental impacts of deep-seabed mining. These result from underestimating mining footprints relative to habitats targeted and poor understanding of the sensitivity, biodiversity, and dynamics of deep-sea ecosystems. Addressing these misconceptions and knowledge gaps is needed for effective management of deep-seabed mining.

Effective altruism is a growing humanitarian movement with a track record of success in evaluating the effectiveness of charitable spending across a wide range of projects. We suggest ways in which the foundations of this movement can be applied to the complex world of conservation.

In many applied cases of ecological and environmental modeling there is sizeable variation in the independent variables as a result of measurement and sampling errors. This uncertainty may lead to biased predictions. It is possible to avoid this problem by increased sampling and by modeling the errors using hierarchical modeling.

The extent to which the age of parents at reproduction can affect offspring lifespan and other fitness-related traits is important in our understanding of the selective forces shaping life history evolution. In this article, the widely reported negative effects of parental age on offspring lifespan (the ‘Lansing effect’) is examined. Outlined herein are the potential routes whereby a Lansing effect

Biotic selective pressures dominate explanations for the evolutionary ecology of tropical endotherms. Yet, abiotic factors, principally precipitation regimes, shape biogeographical and phenological patterns in tropical regions. Despite its importance, we lack a framework for understanding when, why, and how rain affects endotherms. Here, we review how tropical birds and mammals respond to rain at individual

The United Nations (UN) recently declared 2021 to 2030 the Decade on Ecosystem Restoration. Against this background, we review recent social-ecological systems research and summarize key themes that could help to improve ecosystem restoration in dynamic social contexts. The themes relate to resilience and adaptability, ecosystem stewardship and navigation of change, relational values, the coevolution

Tropical biomes are the most diverse plant communities on Earth, and quantifying this diversity at large spatial scales is vital for many purposes. As macroecological approaches proliferate, the taxonomic uncertainties in species occurrence data are easily neglected and can lead to spurious findings in downstream analyses. Here, we argue that technological approaches offer potential solutions, but

Cellular differentiation is one of the hallmarks of complex multicellularity, allowing individual organisms to capitalize on among-cell functional diversity. The evolution of multicellularity is a major evolutionary transition that allowed for the increase of organismal complexity in multiple lineages, a process that relies on the functional integration of cell-types within an individual. Multiple