As of 2018, 55% of the world’s human population lives in villages, towns, or cities, and this figure grows annually as people increasingly adopt the urban lifestyle. The environmental consequences of this urban expansion are vast: grasslands, forests, and wetlands are replaced by roads, sidewalks, and buildings that make up the residential and commercial infrastructure... Continue Reading →
Parallel Evolution of Melanism in Urban Squirrels
Cities offer an unprecedented global experiment for parallel evolutionary change: they similarly differ in several dimensions including climate, land cover, and pollution. Yet few studies examine evolutionary change across multiple cities, which is critical for identifying environmental characteristics that mediate adaptive responses. For example, city size, age, and habitat connectivity may all contribute to the... Continue Reading →
New Lit Alert: Detecting patterns of vertebrate biodiversity across the multidimensional urban landscape
Detecting patterns of vertebrate biodiversity across the multidimensional urban landscape Marina Alberti & Tianzhe Wang Abstract Explicit characterisation of the complexity of urban landscapes is critical for understanding patterns of biodiversity and for detecting the underlying social and ecological processes that shape them. Urban environments exhibit variable heterogeneity and connectivity, influenced by different historical contingencies,... Continue Reading →
New Lit Alert: No evidence for innate differences in tadpole behavior between natural, urbanized, and invasive populations
No evidence for innate differences in tadpole behavior between natural, urbanized, and invasive populations Max Mühlenhaupt, James Baxter-Gilbert, Buyisile G. Makhubo, Julia L. Riley & John Measey Abstract Animals are increasingly challenged to respond to novel or rapidly changing habitats due to urbanization and/or displacement outside their native range by humans. Behavioral differences, such as increased boldness (i.e., propensity for risk-taking), are often observed in animals persisting in novel environments; however, in many cases, it is unclear how these differences arise (e.g., through developmental plasticity or evolution) or when they arise (i.e., at what age or developmental stage). In the Guttural Toad (Sclerophrys gutturalis), adult urban toads from both native and invasive ranges are bolder than conspecifics in natural habitats. Here, we reared Guttural Toad tadpoles in a common garden experiment and tested for innate differences in boldness across their development and between individuals whose parents and lineage came from rural-native, urban-native, and urban-invasive localities (i.e., origin populations). Tadpoles did not differ in their boldness or in how their boldness changed over ontogeny based on their origin populations. In general, tadpoles typically became less bold as they aged, irrespective of origin population. Our findings indicate that differences in boldness in free-living adult Guttural Toads are not innate in the tadpole stage and we discuss three possible mechanisms driving phenotypic divergence in adult boldness for the focus of future research: habitat-dependent developmental effects on tadpole behavior, decoupled evolution between the tadpole and adult stage, and/or behavioral flexibility, learning, or acclimatization during the adult stage.
Top Urban Evolution Papers of 2021
Humans are increasingly a dominant driver of evolutionary change within populations. Since its inception, the Life in the City Blog has brilliantly shown that some of the most stunning examples of human caused evolution relates to how urbanization affects species’ evolution. This area of research has gained a lot of attention from scientists in recent... Continue Reading →
A New Hope for Urban Pit Building Insects
A pit-fall is only as good as the location is deployed. Cities can provide large shaded areas with a layer of soil suitable for trap building. Check out our blog to find out how Wormlion larvae use walls to deploy the perfect pit-fall trap.
Is Plastic Always Fantastic? Selection on Thermal Plasticity in Urban Anoles
A recent publication in Nature Communications goes above and beyond in studying how selection on adaptive and/or maladaptive gene expression plasticity may be regulating thermal tolerance in urban anoles. The importance of plasticity in the colonization of new environments is a widely-accepted argument, however, the role of plasticity in facilitating adaptive evolution remains controversial. Plasticity... Continue Reading →
New Lit Alert: Which Traits Influence Bird Survival in the City? A Review
Which Traits Influence Bird Survival in the City? A Review Swaroop Patankar, Ravi Jambhekar, Kulbhushansingh Ramesh Suryawanshi, and Harini Nagendra Abstract Urbanization poses a major threat to biodiversity worldwide. We focused on birds as a well-studied taxon of interest, in order to review literature on traits that influence responses to urbanization. We review 226 papers... Continue Reading →
New Lit Alert: Recent spread of blue tits into the Barcelona urban environment: morphological differences and the role of balanced dispersal
Recent spread of blue tits into the Barcelona urban environment: morphological differences and the role of balanced dispersal Juan Carlos Senar & Mats Björklund Abstract Rates of phenotypic change are greater in cities than in any other habitat. Consequently, urban habitats are an ideal experimental area to study contemporary evolution and adaptation. A key question... Continue Reading →
New Lit Alert: Bioindicator snake shows genomic signatures of natural and anthropogenic barriers to gene flow
Bioindicator snake shows genomic signatures of natural and anthropogenic barriers to gene flow Damian C. Lettoof, Vicki A. Thomson, Jari Cornelis, Philip W. Bateman, Fabien Aubret, Marthe M. Gagnon, and Brenton von Takach Abstract Urbanisation alters landscapes, introduces wildlife to novel stressors, and fragments habitats into remnant ‘islands’. Within these islands, isolated wildlife populations can... Continue Reading →
Urbanisation Exposes Birds to Metal Pollution
Parallel, urban-driven phenotypic changes There is increasing evidence that, for a given species, individuals inhabiting cities often differ from their counterparts outside of cities. Such differences may result from individuals suffering from environmental conditions in cities. For instance, my colleague Michela Corsini showed that, in the great tit (Parus major) and the blue tit (Cyanistes caeruleus),... Continue Reading →
Moving to the City: Morphology and Performance in Introduced Urban Lizards
Making the best of a difficult year With a group of other students here at Ohio Wesleyan University, I had successfully written a grant to research the common wall lizard (Podarcis muralis) in the south of France for the summer of 2020. Like so many plans that year, this trip was canceled. While the streets... Continue Reading →
City Lizards Hold Their Footing Against a Category 5 Hurricane
Although species will face the challenges of ongoing urbanization and extreme climate events, we know very little about how these disturbances interact. For example, the response to hurricanes has largely been documented for species in their natural habitat. Thus, how urban taxa will respond to hurricanes remains largely unknown. Read on to find out how the anole lizard in Puerto Rico responded to Hurricane Maria for both urban and forest populations.
Genomic Urban Adaptation in a Common Bird Across Europe
Cities, defined as large human settlements of the contemporary human population, have been part of the “Old World” landscape for long time, including Europe. However, the current exponential increase of the urbanised landscape is an unprecedented phenomenon, which has an impact at multiple ecological scales. Urbanisation and its derived actions can fragment wildlife populations and... Continue Reading →
New Research: Early Life Experience Influences Dispersal in Coyotes (Canis latrans)
Coyotes are widespread across North America and are one of few large predators that are found in cities. If you've been following our blog, you may have seen a few pictures of coyotes in urban and residential areas. You have probably also read some great research as well, presented by our guest contributors. Because they... Continue Reading →