Ectothermic animals, such as amphibians and reptiles, are particularly sensitive to rapidly warming global temperatures. One response in these organisms may be to evolve aspects of their thermal physiology. If this response is adaptive and can occur on the appropriate time scale, it may facilitate population or species persistence in the changed environments. However, thermal physiological traits have classically been thought to evolve too slowly to keep pace with environmental change in longer‐lived vertebrates. Even as empirical work of the mid‐20th century offers mixed support for conservatism in thermal physiological traits, the generalization of low evolutionary potential in thermal traits is commonly invoked. Here, we revisit this hypothesis to better understand the mechanisms guiding the timing and patterns of physiological evolution. Characterizing the potential interactions among evolution, plasticity, behavior, and ontogenetic shifts in thermal physiology is critical for accurate prediction of how organisms will respond to our rapidly warming world. Recent work provides evidence that thermal physiological traits are not as evolutionarily rigid as once believed, with many examples of divergence in several aspects of thermal physiology at multiple phylogenetic scales. However, slow rates of evolution are often still observed, particularly at the warm end of the thermal performance curve. Furthermore, the context‐specificity of many responses makes broad generalizations about the potential evolvability of traits tenuous. We outline potential factors and considerations that require closer scrutiny to understand and predict reptile and amphibian evolutionary responses to climate change, particularly regarding the underlying genetic architecture facilitating or limiting thermal evolution.

Urbanization transforms environments in ways that alter biological evolution. We examined whether urban environmental change drives parallel evolution by sampling 110,019 white clover plants from 6169 populations in 160 cities globally. Plants were assayed for a Mendelian antiherbivore defense that also affects tolerance to abiotic stressors. Urban-rural gradients were associated with the evolution of clines in defense in 47% of cities throughout the world. Variation in the strength of clines was explained by environmental changes in drought stress and vegetation cover that varied among cities. Sequencing 2074 genomes from 26 cities revealed that the evolution of urban-rural clines was best explained by adaptive evolution, but the degree of parallel adaptation varied among cities. Our results demonstrate that urbanization leads to adaptation at a global scale.

Across all taxa, amphibians exhibit some of the strongest phenological shifts in response to climate change. As climates warm, amphibians and other animals are expected to breed earlier in response to temperature cues. However, if species use fixed cues such as daylight, their breeding timing might remain fixed, potentially creating disconnects between their life history and environmental conditions. Wood frogs Rana sylvatica are a cold‐adapted species that reproduce in early spring, immediately after breeding ponds are free of ice. We used long‐term surveys of wood frog oviposition timing in 64 breeding ponds over 20 yr to show that, despite experiencing a warming of 0.29°C per decade in annual temperature, wood frog breeding phenology has shifted later by 2.8 d since 2000 (1.4 d per decade; 4.8 d per °C). This counterintuitive pattern is likely the result of changes in the timing of snowpack accumulation and melting. Finally, we used relationships between climate and oviposition between 2000 and 2018 to hindcast oviposition dates from climate records to model longer‐term trends since 1980. Our study indicates that species can respond to fine‐grained seasonal climate heterogeneity within years that is not apparent or counterintuitive when related to annual trends across years.

Over the past two decades, our knowledge of the ecological impacts of roads has increased rapidly. It is now clear that the environmental effects of transportation infrastructure are inextricable from transportation benefits to economic, social, and cultural values. Despite the necessity of optimizing these multiple values, road planners, scientists, and practitioners have no established methodology or pluralistic approach to address growing ethical complexities. We articulate five ethical issues that could be addressed by developing an ethic of road ecology in order to facilitate the identification, reasoning, and harmonization of ethical dimensions of road planning and development. This inquiry into road ecology can draw lessons from existing applied ethics, such as in ecological restoration and urban planning, to build a narrative that is informed by both science and ethics. We illustrate five ethical issues presented through case studies that elaborate on the motivations, responsibilities, and duties that should be considered in ethically and scientifically complicated road building decisions. To address these issues, we encourage the development of a code of ethics, dedicated intellectual forums, and practical guidance to assist road planners, and more broadly transportation practitioners, to resolve complex ethical quandaries systematically. We hope this perspective encourages conversation for a holistic yet pragmatic approach to this applied ethics problem, while also assisting responsible parties as they navigate difficult moral terrain.

Accurate estimates of forest canopy structure are central for a wide range of ecological studies. Hemispherical photography (HP) is a popular tool to estimate canopy attributes. However, traditional HP methods require expensive equipment, are sensitive to exposure settings, and produce limited resolution which dramatically affects the accuracy of gap fraction estimates. As an alternative, hemispherical images can be extracted from spherical panoramas produced by many smartphone camera applications. I compared hemispherical photos captured with a digital single lens reflex camera and 180° lens to those extracted from smartphone spherical panoramas (SSP). The SSP HP method leverages built-in features of current generation smartphones to produce sharper images of higher resolution, resulting in more definition of fine canopy structure. Canopy openness and global site factor from SSP HP are highly correlated with traditional methods (R2 > 0.9), while leaf area index estimates are lower, especially in more closed canopies where traditional methods fail to capture fine gaps.

Rats thrive in human-dominated landscapes and have expanded to a near global distribution. Norway rats (Rattus norvegicus) contaminate food, damage infrastructure, and are reservoirs for zoonotic pathogens that cause human diseases. To limit these negative impacts, entities around the world implement intervention and control strategies designed to quickly and drastically reduce the number of rats in a population. While the primary goal of these interventions is to reduce rat numbers and their detrimental activities, there are important, yet unexplored, population genetic implications for these rapid population declines. Here, we compare the population genetics of R. norvegicus before, immediately after, and several months following a rodenticide-based eradication campaign targeting rats in an urban slum of Salvador, Brazil. This slum has been the focus of long-term research designed to understand and reduce the risk of leptospirosis for people in this area. We also look for a clear source of rats contributing to population recovery, by either rebounding through breeding of local survivors, or by immigration/reinvasion of the site. We found evidence of severe genetic bottlenecks, with the effective population size dropping 85-91% after eradication, consistent with declines in population sizes. These rapid declines also led to a strong shift in the genetic structure of rats before and after the eradication campaign. Relatedness increased in two of the three study areas after eradication, suggesting reduced population sizes and an uneven impact of the campaign across colonies within the population. Lastly, dozens of low-frequency alleles (mean frequency of 0.037) observed before the campaign were undetected after the campaign, potentially lost from the population via drift or selection. We discuss the public health and ecological implications of these rapid genetic impacts of urban control efforts. Our data suggests that targeting the genetic viability of rat populations may be another important component for integrated pest management (IPM) strategies, designed to reduce urban rats.

Environmental change is predicted to accelerate into the future and will exert strong selection pressure on biota. Although many species may be fated to extinction, others may survive through their capacity to evolve rapidly at highly localized (i.e., microgeographic) scales. Yet, even as new examples have been discovered, the limits to such evolutionary responses have not often been evaluated. One of the first examples of microgeographic variation involved pond populations of wood frogs (Rana sylvatica). Although separated by just tens to hundreds of meters, these populations exhibited countergradient variation in intrinsic embryonic development rates when reared in a common garden. We repeated this experiment 17 years (approximately six to nine generations) later and found that microgeographic variation persists in contemporary populations. Furthermore, we found that contemporary embryos have evolved to develop 14-19% faster than those in 2001. Structural equation models indicate that the predominant cause for this response is likely due to changes in climate over the intervening 17 years. Despite potential for rapid and fine-scale evolution, demographic declines in populations experiencing the greatest changes in climate and habitat imply a limit to the species' ability to mitigate extreme environmental change.

Understanding drivers of metapopulation dynamics remains a critical challenge for ecology and conservation. In particular, the degree of synchrony in metapopulation dynamics determines how resilient a metapopulation is to a widespread disturbance. In this study, we used 21 years of egg mass count data across 64 nonpermanent freshwater ponds in Connecticut, USA to evaluate patterns of abundance and growth and to assess regional as well as local factors in shaping the population dynamics of wood frogs (Rana sylvatica = Lithobates sylvaticus). In particular, we asked whether a species known to undergo metapopulation dynamics exhibited spatial synchrony in abundances. With the exception of a single year when breeding took place during severe drought conditions, our analyses revealed no evidence of synchrony despite close proximity (mean minimum distance < 300 m) of breeding ponds across the 3213‐ha study area. Instead, local, pond‐scale conditions best predicted patterns of abundance and population growth rate. We found negative density dependence on population growth rate within ponds as well as evidence that larger neighboring pond populations had a negative effect on focal ponds. Beyond density, pond depth was a critical predictor; deeper ponds supported larger populations. Drought conditions and warm winters negatively affected populations. Overall, breeding ponds vary in critical ways that either support larger, more persistent populations or smaller populations that are not represented by breeding pairs in some years. The infrequency of spatial synchrony in this system is surprising and suggests greater resilience to stressors than would have been expected if dynamics were strongly synchronized. More generally, understanding the characteristics of systems that determine synchronous population dynamics will be critical to predicting which species are more or less resilient to widespread disturbances like land conversion or climate change.