Jason Munshi-South

Despite growing investments in nature-based solutions for urban resilience, their design often overlooks a fundamental biological process: evolution. Populations of organisms that sustain nature-based solutions are dynamic and can evolve over time. Rapid evolutionary changes, driven by urban environmental stressors, such as pollution, climate extremes, and habitat fragmentation, can reshape species' traits, alter interactions, and shift ecosystem functions. We synthesize evidence of evolutionary change across systems that serve as nature-based solutions in urban contexts and show how evolutionary processes can enhance or undermine their performance. We propose four testable hypotheses linking evolutionary dynamics to nature-based solutions and outline design strategies to maintain adaptive potential. Integrating evolution into nature-based solutions is essential to ensure long-term and efficient functionality under accelerating environmental change.

Trophic dynamics can be altered in complex ways as a result of urbanization. Understanding predator diets in these contexts may not only provide insight into these changes, but also in sources of mortality for vulnerable prey species like the New England cottontail (Sylvilagus transitionalis). However, studying the diets of mammalian predators such as bobcats (Lynx rufus) can be challenging because of their elusive behavior. DNA metabarcoding of stomach contents from roadkill is a method which provides a new opportunity to study predator diets when mortality events occur. We used this technique to examine variation in bobcat diet across a range of urbanized environments in Connecticut, USA, as well as determine whether bobcats consume the declining New England cottontail. DNA metabarcoding identified between two and five species in the majority of bobcat stomachs. Cottontail (Sylvilagus spp.) and eastern gray squirrel (Sciurus carolinensis) were each found in over 80% of samples, and most remaining taxa were other small mammals. Nearly a third of the bobcats had consumed white-tailed deer (Odocoileus virginianus). Stomach contents containing cottontail remains were sequenced at an additional species-specific marker, but no samples containing the New England cottontail were identified. Bobcats in Connecticut consumed a wide variety of natural prey species including a relatively high proportion of semi-aquatic mammals, and we found no evidence of domestic dog or cat consumption. DNA metabarcoding of stomach contents is an effective approach for opportunistically examining predator diet, and our use of this tool may provide a more complete picture of bobcat diet where other techniques have failed to do so.

Urbanization has been a defining feature of the past four centuries, with most of the global population now living in highly modified environments shared with wildlife. Traditionally, biological urban evolutionary research has focused on physical factors such as habitat fragmentation, pollution and resource availability, often overlooking the social and political forces shaping urban environments. This Review explores how religion, politics and war drive urban wildlife evolution by shaping environmental conditions and selective pressures. We synthesize existing knowledge on these influences and propose testable hypotheses to advance the field. Understanding these dynamics is essential for explaining the variability in urban evolutionary processes and predicting the future development of urban systems. By integrating social and political dimensions, we can gain deeper insights into how cities shape the evolution of organisms that inhabit them.

Urbanization is hypothesized to isolate populations and restrict dispersal, leading to reduced genetic diversity and increased genetic differentiation. We tested this hypothesis in specialist herbivorous insects of milkweed, positing that higher dispersal ability would mitigate the negative effects of urbanization on genetic drift and gene flow, and that these effects would vary with city size. In this study, we collected 383 milkweed insects from urban and rural sites in Toronto, Canada, and five surrounding cities. Using ddRADseq, we generated 145,000 SPNs for monarchs, 10,000 SNPs for beetles, 6,000 SNPs for weevils to quantify genetic diversity, demographic history and population genetic structure. Contrary to our hypotheses, our results indicated no effect of urbanization or dispersal ability on diversity or genetic differentiation. Genetic diversity, measured as π, varied between 0.0013 and 0.0044 across species, with no urban vs. rural component, but with monarchs having >2 X higher diversity compared to beetles and weevils. Similarly, genetic differentiation was generally low, FST varying between 0.01 and 0.28, but there are no consistent trends among urban vs. rural samples for any of the three species. However, demographic analyses revealed a consistent decline in effective population size for all three sampled species, beginning around the last glacial maximum and intensifying over the past 1,000 years. Our findings suggest that both urbanization and dispersal ability have not been a major factor in reducing gene flow or increasing genetic drift among milkweed's herbivorous insect populations. Instead, historical events such as climatic change since the last glacial maximum, and large-scale anthropogenic disturbance in general, have had a more pronounced impact on demography. These results highlight the importance of considering the combined effects of natural and anthropogenic long-term historical processes when studying population genetics in the context of urbanization.

The brown rat (Rattus norvegicus) occupies nearly every terrestrial habitat with a human presence and is one of our most important model organisms. Despite this prevalence, gaps remain in understanding the evolution of brown rat commensalism, their global dispersal, and mechanisms underlying contemporary adaptations to diverse environments. In this Review, we explore recent advances in the evolutionary history of brown rats and discuss key challenges, including finding and accurately dating historical specimens, disentangling histories of multiple domestication events, and synthesizing functional variation in wild rat populations with the development of laboratory strains. Advances in zooarchaeology and population genomics will usher in a new golden age of research on the evolutionary biology of brown rats, with positive feedbacks on their use as biomedical models.The brown rat (Rattus norvegicus) occupies nearly every terrestrial habitat with a human presence and is one of our most important model organisms. Despite this prevalence, gaps remain in understanding the evolution of brown rat commensalism, their global dispersal, and mechanisms underlying contemporary adaptations to diverse environments. In this Review, we explore recent advances in the evolutionary history of brown rats and discuss key challenges, including finding and accurately dating historical specimens, disentangling histories of multiple domestication events, and synthesizing functional variation in wild rat populations with the development of laboratory strains. Advances in zooarchaeology and population genomics will usher in a new golden age of research on the evolutionary biology of brown rats, with positive feedbacks on their use as biomedical models.

Urban evolutionary ecology is inherently interdisciplinary. Moreover, it is a field with global significance. However, bringing researchers and resources together across fields and countries is challenging. Therefore, an online collaborative research hub, where common methods and best practices are shared among scientists from diverse geographic, ethnic, and career backgrounds would make research focused on urban evolutionary ecology more inclusive. Here, we describe a freely available online research hub for toolkits that facilitate global research in urban evolutionary ecology. We provide rationales and descriptions of toolkits for: (1) decolonizing urban evolutionary ecology; (2) identifying and fostering international collaborative partnerships; (3) common methods and freely‐available datasets for trait mapping across cities; (4) common methods and freely‐available datasets for cross‐city evolutionary ecology experiments; and (5) best practices and freely available resources for public outreach and communication of research findings in urban evolutionary ecology. We outline how the toolkits can be accessed, archived, and modified over time in order to sustain long‐term global research that will advance our understanding of urban evolutionary ecology.
Advancing urban evolutionary ecology will require a global perspective, yet many barriers currently prevent scholars from the global south and north from effectively collaborating. We developed toolkits that are flexible, reliable, and accessible on a website to facilitate effective collaborations across geographic boundaries in urban evolutionary ecology.

Climate change and urbanization are two of the most prominent global drivers of biodiversity and ecosystem change. Fully understanding, predicting and mitigating the biological impacts of climate change and urbanization are not possible in isolation, especially given their growing importance in shaping human society. Here we develop an integrated framework for understanding and predicting the joint effects of climate change and urbanization on ecology, evolution and their eco-evolutionary interactions. We review five examples of interactions and then present five hypotheses that offer opportunities for predicting biodiversity and its interaction with human social and cultural systems under future scenarios. We also discuss research opportunities and ways to design resilient landscapes that address both biological and societal concerns. In this Perspective, the authors develop an integrated framework to understand and predict the joint impacts of climate change and urbanization on biodiversity and ecosystems. They review examples of interacting impacts and present opportunities for future research.

Increasing evidence suggests that urbanization is associated with higher mutation rates, which can affect the health and evolution of organisms that inhabit cities. Elevated pollution levels in urban areas can induce DNA damage, leading to de novo mutations. Studies on mutations induced by urban pollution are most prevalent in humans and microorganisms, whereas studies of non-human eukaryotes are rare, even though increased mutation rates have the potential to affect organisms and their populations in contemporary time. Our Perspective explores how higher mutation rates in urban environments could impact the fitness, ecology and evolution of populations. Most mutations will be neutral or deleterious, and higher mutation rates associated with elevated pollution in urban populations can increase the risk of cancer in humans and potentially other species. We highlight the potential for urban-driven increased deleterious mutational loads in some organisms, which could lead to a decline in population growth of a wide diversity of organisms. Although beneficial mutations are expected to be rare, we argue that higher mutation rates in urban areas could influence adaptive evolution, especially in organisms with short generation times. Finally, we explore avenues for future research to better understand the effects of urban-induced mutations on the fitness, ecology and evolution of city-dwelling organisms.