scholarly journals Multivariate phenotypic divergence along an urbanization gradient

2019 ◽  
Author(s):  
James S. Santangelo ◽  
Carole Advenard ◽  
L. Ruth Rivkin ◽  
Ken A. Thompson
Keyword(s):  
Urban Areas ◽  
Natural Populations ◽  
Common Garden ◽  
Urban Environments ◽  
Floral Traits ◽  
Adaptive Divergence ◽  
Phenotypic Traits ◽  
The Novel ◽  
Urbanization Gradient ◽  
Growing Body

AbstractA growing body of evidence suggests that natural populations can evolve to better tolerate the novel environmental conditions associated with urban areas. Invariably, studies of adaptive divergence in urban areas examine only one or a few traits at a time from populations residing only at the most extreme urban and nonurban habitats. Thus, whether urbanization is driving divergence in many traits simultaneously in a manner that varies with the degree of urbanization remains unclear. To address this gap, we generated seed families of white clover (Trifolium repens) collected from 27 populations along an urbanization gradient in Toronto, Canada, and grew them up to measure multiple phenotypic traits in a common garden. Overall, urban populations had later phenology and germination, larger flowers, thinner stolons, reduced cyanogenesis, greater biomass, and were more attractive to pollinators. Pollinator observations revealed near complete turnover between urban and nonurban sites, which may explain some of the observed divergence in floral traits and phenology. Our results suggest that adaptation to urban environments involves multiple organismal traits.

scholarly journals Multivariate phenotypic divergence along an urbanization gradient

2020 ◽  
Vol 16 (9) ◽  
pp. 20200511
Author(s):  
James S. Santangelo ◽  
L. Ruth Rivkin ◽  
Carole Advenard ◽  
Ken A. Thompson
Keyword(s):  
Urban Areas ◽  
Natural Populations ◽  
Common Garden ◽  
Urban Environments ◽  
Adaptive Divergence ◽  
Phenotypic Traits ◽  
The Novel ◽  
Multiple Traits ◽  
Urbanization Gradient ◽  
Urban Sites

Evidence suggests that natural populations can evolve to better tolerate the novel environmental conditions associated with urban areas. Studies of adaptive divergence in urban areas often examine one or a few traits at a time from populations residing only at the most extreme urban and nonurban habitats. Thus, whether urbanization drives divergence in many traits simultaneously in a manner that varies with the degree of urbanization remains unclear. To address this gap, we generated seed families of white clover ( Trifolium repens ) collected from 27 populations along an urbanization gradient in Toronto, Canada, grew them in a common garden, and measured 14 phenotypic traits. Families from urban sites had evolved later phenology and germination, larger flowers, thinner stolons, reduced cyanogenesis, greater biomass and greater seed set. Pollinator observations revealed near-complete turnover of pollinator morphological groups along the urbanization gradient, which may explain some of the observed divergences in floral traits and phenology. Our results suggest that adaptation to urban environments involves multiple traits.

scholarly journals Evolutionary inference from QST-FST comparisons: disentangling local adaptation from altitudinal gradient selection in snapdragon plants

2018 ◽  
Author(s):  
Sara Marin ◽  
Juliette Archambeau ◽  
Vincent Bonhomme ◽  
Mylène Lascoste ◽  
Benoit Pujol
Keyword(s):  
Local Adaptation ◽  
Natural Populations ◽  
Common Garden ◽  
Global Scale ◽  
Structured Populations ◽  
Adaptive Divergence ◽  
Adaptation To Climate Change ◽  
Phenotypic Differentiation ◽  
Multiple Populations ◽  
Environmental Demand

ABSTRACTPhenotypic differentiation among natural populations can be explained by natural selection or by neutral processes such as drift. There are many examples in the literature where comparing the effects of these processes on multiple populations has allowed the detection of local adaptation. However, these studies rarely identify the agents of selection. Whether population adaptive divergence is caused by local features of the environment, or by the environmental demand emerging at a more global scale, for example along altitudinal gradients, is a question that remains poorly investigated. Here, we measured neutral genetic (FST) and quantitative genetic (QST) differentiation among 13 populations of snapdragon plants (Antirrhinum majus) in a common garden experiment. We found low but significant genetic differentiation at putatively neutral markers, which supports the hypothesis of either ongoing pervasive homogenisation via gene flow between diverged populations or reproductive isolation between disconnected populations. Our results also support the hypothesis of local adaptation involving phenological, morphological, reproductive and functional traits. They also showed that phenotypic differentiation increased with altitude for traits reflecting the reproduction and the phenology of plants, thereby confirming the role of such traits in their adaptation to environmental differences associated with altitude. Our approach allowed us to identify candidate traits for the adaptation to climate change in snapdragon plants. Our findings imply that environmental conditions changing with altitude, such as the climatic envelope, influenced the adaptation of multiple populations of snapdragon plants on the top of their adaptation to local environmental features. They also have implications for the study of adaptive evolution in structured populations because they highlight the need to disentangle the adaptation of plant populations to climate envelopes and altitude from the confounding effects of selective pressures acting specifically at the local scale of a population.

scholarly journals Multivariate distributions of behavioural, morphological, and ontogenetic traits in hybrids bring new insights into the divergence of sympatric Arctic charr morphs

2020 ◽  
Author(s):  
Quentin J.B. Horta-Lacueva ◽  
Sigurður S. Snorrason ◽  
Michael B. Morrissey ◽  
Camille A. Leblanc ◽  
Kalina H. Kapralova
Keyword(s):  
Salvelinus Alpinus ◽  
Arctic Charr ◽  
Common Garden ◽  
Covariance Structures ◽  
Adaptive Divergence ◽  
Phenotypic Traits ◽  
Phenotypic Variance ◽  
Multivariate Distributions ◽  
Phenotypic Novelty ◽  
Trait Covariance

AbstractStudying the development of fitness related traits in hybrids from populations diverging in sympatry is a fundamental approach to understand the processes of speciation. However, such traits are often affected by covariance structures that complicate the comprehension of these processes, especially because the interactive relationships between traits of different nature (e.g. morphology, behaviour, life-history) remain largely unknown in this context. In a common garden setup, we conducted an extensive examination of phenotypic traits suspected to be involved in the divergence of two recently evolved morphs of Arctic charr (Salvelinus alpinus), and investigated the consequences of potential patterns of trait covariance on the phenotype of their hybrids. We observed differences among morphs in overall phenotypic variance and in trait correlations. Phenotypic contrainsts also tended to be reduced in the hybrids, which corroborates the narrative of hybridization facilitating adaptive divergence by relaxing trait covariance. However, the hybrids were associated with reduced phenotypic variance at different scales (i.e. at the scale of the entire P matrix and in different parts of the multivariate space), and we identified stronger correlations between several ontogenetic and morphological traits in the hybrids than in both morphs. These findings suggest a limited potential for hybridization to generate phenotypic novelty, and emphasise the need for multivariate approaches conciliating ontogenetic, morphological and behavioural processes to study the processes of adaptive divergence and speciation.

scholarly journals Consistent signatures of urban adaptation in a native, urban invader ant Tapinoma sessile

2021 ◽  
Author(s):  
Alexander Joseph Blumenfeld ◽  
Pierre Andre Eyer ◽  
Anjel M Helms ◽  
Grzegorz Buczkowski ◽  
Edward L Vargo
Keyword(s):  
Urban Areas ◽  
Natural Populations ◽  
The United States ◽  
Urban Environments ◽  
Natural Environments ◽  
Urban Habitats ◽  
Tapinoma Sessile ◽  
The Social ◽  
Odorous House Ant ◽  
Single Nest

Biological invasions are becoming more prevalent due to the rise of global trade and expansion of urban areas. Ants are among the most prolific invaders, with many exhibiting a multi-queen colony structure, dispersal through budding and a lack of inter-nest aggression. Although these characteristics are generally associated with the invasions of exotic ants, they may also facilitate the spread of native ants into novel habitats (e.g., urban areas). Native to North American forests, the odorous house ant Tapinoma sessile has become abundant in urban environments throughout the United States. Forest-dwelling colonies typically have a small workforce, inhabit a single nest, and are headed by a single queen, whereas urban colonies tend to be several orders of magnitude larger, inhabit multiple nests and are headed by multiple queens. Here, we explore and compare the population genetic and breeding structure of T. sessile within and between urban and natural environments in several localities across its distribution range. We found the social structure of a colony to be a plastic trait in both habitats, although extreme polygyny (i.e., nests with multiple queens) was confined to urban habitats. Additionally, polydomous colonies (i.e., nests lacking genetic differentiation and behavioral antagonism) were only present in urban habitats, suggesting T. sessile can only achieve unicoloniality within urbanized areas. Finally, we identified strong differentiation between urban and natural populations in each locality and continent-wide, indicating cities may restrict gene flow and exert intense selection pressure. Overall, our study highlights urbanization's influence in charting the evolutionary course for species.

scholarly journals The evolution of city life

2018 ◽  
Vol 285 (1884) ◽  
pp. 20181529 ◽  
Author(s):  
James S. Santangelo ◽  
L. Ruth Rivkin ◽  
Marc T. J. Johnson
Keyword(s):  
Urban Areas ◽  
Evolutionary Biology ◽  
Natural Populations ◽  
Leading Edge ◽  
Theoretical Models ◽  
Global Scale ◽  
Urban Environments ◽  
Ecological Communities ◽  
Natural Ecosystems ◽  
Evolutionary Mechanisms

Urbanization represents a dominant and growing form of disturbance to Earth's natural ecosystems, affecting biodiversity and ecosystem services on a global scale. While decades of research have illuminated the effects of urban environmental change on the structure and function of ecological communities in cities, only recently have researchers begun exploring the effects of urbanization on the evolution of urban populations. The 15 articles in this special feature represent the leading edge of urban evolutionary biology and address existing gaps in our knowledge. These gaps include: (i) the absence of theoretical models examining how multiple evolutionary mechanisms interact to affect evolution in urban environments; (ii) a lack of data on how urbanization affects natural selection and local adaptation; (iii) poor understanding of whether urban areas consistently affect non-adaptive and adaptive evolution in similar ways across multiple cities; (iv) insufficient data on the genetic and especially genomic signatures of urban evolutionary change; and (v) limited understanding of the evolutionary processes underlying the origin of new human commensals. Using theory, observations from natural populations, common gardens, genomic data and cutting-edge population genomic and landscape genetic tools, the papers in this special feature address these gaps and highlight the power of urban evolutionary biology as a globally replicated ‘experiment’ that provides a powerful approach for understanding how human altered environments affect evolution.

scholarly journals Selective disappearance of great tits with short telomeres in urban areas

2017 ◽  
Vol 284 (1862) ◽  
pp. 20171349 ◽  
Author(s):  
Pablo Salmón ◽  
Johan F. Nilsson ◽  
Hannah Watson ◽  
Staffan Bensch ◽  
Caroline Isaksson
Keyword(s):  
Urban Environment ◽  
Urban Areas ◽  
Strong Predictor ◽  
Adult Population ◽  
Later Life ◽  
Urban Environments ◽  
Phenotypic Traits ◽  
Telomere Attrition ◽  
Rural Environments ◽  
The Relationship

Urban environments pose novel challenges, as well as opportunities, for urban-dwelling wildlife. Although differences have been reported in several phenotypic traits (e.g. morphology, physiology and behaviour) between urban and rural populations, it is poorly understood whether this affects individual fitness. Telomere dynamics are posited as one possible mechanism underlying senescence and mortality. It was recently shown that telomere shortening is accelerated when growing up in an urban, compared with a rural, environment. However, the implications of accelerated telomere attrition for fitness are still unclear. Here, we examine the relationship between telomere length (TL) and survival in a bird common to urban and rural environments, and during both early and later life. The results reveal that TL is a strong predictor of post-fledging survival and recruitment in both habitats but, crucially, selective disappearance of individuals with short telomeres early in life is more pronounced in the urban environment, resulting in a longer average TL among the adult population. However, following recruitment, we found no difference in the relationship between TL and survival between the urban and rural environments. This indicates that the urban environment has negative effects in early life, while during later life the benefits could potentially outweigh the costs.

scholarly journals Adaptive Divergence of Meiotic Recombination Rate in Ecological Speciation

2020 ◽  
Vol 12 (10) ◽  
pp. 1869-1881
Author(s):  
Swatantra Neupane ◽  
Sen Xu
Keyword(s):  
Meiotic Recombination ◽  
Recombination Rate ◽  
Natural Populations ◽  
Daphnia Pulex ◽  
Common Garden ◽  
Population Level ◽  
Directional Selection ◽  
Neutral Evolution ◽  
Adaptive Divergence ◽  
Rate Variation

Abstract Theories predict that directional selection during adaptation to a novel habitat results in elevated meiotic recombination rate. Yet the lack of population-level recombination rate data leaves this hypothesis untested in natural populations. Here, we examine the population-level recombination rate variation in two incipient ecological species, the microcrustacean Daphnia pulex (an ephemeral-pond species) and Daphnia pulicaria (a permanent-lake species). The divergence of D. pulicaria from D. pulex involved habitat shifts from pond to lake habitats as well as strong local adaptation due to directional selection. Using a novel single-sperm genotyping approach, we estimated the male-specific recombination rate of two linkage groups in multiple populations of each species in common garden experiments and identified a significantly elevated recombination rate in D. pulicaria. Most importantly, population genetic analyses show that the divergence in recombination rate between these two species is most likely due to divergent selection in distinct ecological habitats rather than neutral evolution.

scholarly journals Nutrient availability in urban food waste: carbohydrate bias in the Philadelphia–Camden urban matrix

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Melissa Carpenter ◽  
Amy M Savage
Keyword(s):  
Food Waste ◽  
Urban Areas ◽  
Urban Environments ◽  
Behavioral Changes ◽  
The Novel ◽  
Natural Diet ◽  
Human Food ◽  
Food Subsidies ◽  
The Impact ◽  
Urban Matrix

Abstract Urban areas provide animals with both a unique set of challenges and resources. One of the novel resources available in urban areas is an abundance of human food waste. Although it is known that many urban-dwelling animals are consuming human food waste at some level, there is not a good understanding of the nutrients provided by this novel resource. Given that human food waste is unlikely to resemble an animal’s natural diet, there could be health consequences for an animal consuming human food waste. In some animals, nutritional imbalances can also lead to behavioral changes, making it important to understand more precisely what they are eating. To answer the question of what nutrients were available in urban food waste, we surveyed food waste in the Philadelphia–Camden urban matrix. We found that human food waste contained ∼1000% more carbohydrates than other nutrient types. Given the impact that carbohydrate-rich diets can have on human health, there may be important consequences for the animals in urban environments that consume this food waste. Therefore, it is possible that human food subsidies have cascading consequences for entire communities and their ecosystem services in cities.

scholarly journals Urbanization negatively impacts frog diversity at continental, regional, and local scales

2021 ◽  
Author(s):  
Corey Thomas Callaghan ◽  
Gracie Liu ◽  
Brittany A. Mitchell ◽  
Ailstair G. B. Poore ◽  
Jodi Rowley
Keyword(s):  
Species Richness ◽  
Urban Areas ◽  
Phylogenetic Diversity ◽  
Land Development ◽  
Urban Environments ◽  
Urbanization Gradient ◽  
Continental Scale ◽  
Shannon Diversity ◽  
Steady Decrease ◽  
Negative Impacts

Urban environments are novel ecosystems, with increased chemical, sound, and light pollution differentially impacting many animals. Understanding the impacts of urban environments on biodiversity is the first step to understanding how to best mitigate biodiversity losses in an increasingly urbanizing world. Analyses with broad geographic and taxonomic coverage can offer critical context for informing urban biodiversity conservation. But such studies are currently lacking, especially for under-studied but likely highly impacted taxa such as frogs. Our objective was to document frog diversity in relation to urban environments at continental, regional, and local scales. We used FrogID data — an opportunistic citizen science dataset generated by volunteers recording calling frogs using a smartphone and validated by experts — throughout continental Australia, to calculate species richness, Shannon diversity, and phylogenetic diversity of frogs in urban and non-urban areas, as well as along a continuous urbanization gradient. The overall species richness of frogs was, on average, 57% less in urban than non-urban areas across six ecoregions. Further, we found significantly lower frog diversity in urban environments compared with non-urban environments across the country, with an average reduction of 59% species richness, 86% Shannon diversity, and 72% phylogenetic diversity. We also found evidence for a steady decrease in frog diversity along an urbanization gradient, with no obvious thresholds. Our results highlight the negative impacts of urbanization — at a continental scale — on frog diversity, and clearly highlight the necessity to consider frog diversity in future urban land development decisions.

scholarly journals Modern spandrels: The roles of genetic drift, gene flow and natural selection in the formation of parallel clines

2018 ◽  
Author(s):  
James S. Santangelo ◽  
Marc T. J. Johnson ◽  
Rob W. Ness
Keyword(s):  
Gene Flow ◽  
Natural Selection ◽  
Genetic Architecture ◽  
Natural Populations ◽  
Urban Environments ◽  
Phenotypic Change ◽  
Phenotypic Traits ◽  
Evolutionary Processes ◽  
Urbanization Gradients

AbstractUrban environments offer the opportunity to study the role of adaptive and non-adaptive evolutionary processes on an unprecedented scale. While the presence of parallel clines in heritable phenotypic traits is often considered strong evidence for the role of natural selection, non-adaptive evolutionary processes can also generate clines, and this may be more likely when traits have a non-additive genetic basis due to epistasis. In this paper, we use spatially-explicit simulations modelled according to the cyanogenesis (HCN) polymorphism in white clover (Trifolium repens) to examine the formation of phenotypic clines along urbanization gradients under varying levels of drift, gene flow and selection. HCN results from an epistatic interaction between two Mendelian-inherited loci. Our results demonstrate that the genetic architecture of this trait makes natural populations susceptible to decreases in HCN frequencies via drift. Gradients in the strength of drift across a landscape resulted in phenotypic clines with lower frequencies of HCN in strongly drifting populations, giving the misleading appearance of deterministic adaptive changes in the phenotype. Studies of heritable phenotypic change in urban populations should generate null models of phenotypic evolution based on the genetic architecture underlying focal traits prior to invoking selection’s role in generating adaptive differentiation.

Sign in / Sign up

Export Citation Format

Share Document