scholarly journals Evolutionary and ecological processes influencing chemical defense variation in an aposematic and mimetic Heliconius butterfly

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11523
Author(s):  
Anniina L. K. Mattila ◽  
Chris D. Jiggins ◽  
Øystein H. Opedal ◽  
Gabriela Montejo-Kovacevich ◽  
Érika C. Pinheiro de castro ◽  
...  
Keyword(s):  
Intraspecific Variation ◽  
Adaptive Evolution ◽  
Evolutionary Dynamics ◽  
De Novo ◽  
Environmental Gradients ◽  
Natural Populations ◽  
Common Garden ◽  
Skewed Distribution ◽  
Evolutionary Potential ◽  
Ecological Processes

Chemical defences against predators underlie the evolution of aposematic coloration and mimicry, which are classic examples of adaptive evolution. Surprisingly little is known about the roles of ecological and evolutionary processes maintaining defence variation, and how they may feedback to shape the evolutionary dynamics of species. Cyanogenic Heliconius butterflies exhibit diverse warning color patterns and mimicry, thus providing a useful framework for investigating these questions. We studied intraspecific variation in de novo biosynthesized cyanogenic toxicity and its potential ecological and evolutionary sources in wild populations of Heliconius erato along environmental gradients, in common-garden broods and with feeding treatments. Our results demonstrate substantial intraspecific variation, including detectable variation among broods reared in a common garden. The latter estimate suggests considerable evolutionary potential in this trait, although predicting the response to selection is likely complicated due to the observed skewed distribution of toxicity values and the signatures of maternal contributions to the inheritance of toxicity. Larval diet contributed little to toxicity variation. Furthermore, toxicity profiles were similar along steep rainfall and altitudinal gradients, providing little evidence for these factors explaining variation in biosynthesized toxicity in natural populations. In contrast, there were striking differences in the chemical profiles of H. erato from geographically distant populations, implying potential local adaptation in the acquisition mechanisms and levels of defensive compounds. The results highlight the extensive variation and potential for adaptive evolution in defense traits for aposematic and mimetic species, which may contribute to the high diversity often found in these systems.

Adaptation

2016 ◽  
Author(s):  
Andrew P. Hendry
Keyword(s):  
Genetic Variation ◽  
Adaptive Evolution ◽  
Evolutionary Dynamics ◽  
Natural Populations ◽  
Phenotypic Change ◽  
Adaptive Landscapes ◽  
Local Environments ◽  
Short And Long Term ◽  
Different Populations

This chapter outlines how to conceptualize and predict adaptive evolution based on information about selection and genetic variation. It introduces and explains adaptive landscapes, a concept that has proven useful in guiding the understanding of evolution. The chapter also reviews empirical data to answer fundamental questions about adaptation in nature, including to what extent short- and long-term evolution is predictable, how fast is phenotypic change, to what extent is adaptation constrained by genetic variation, and how well adapted natural populations are to their local environments. Moving beyond selection and adaptation within populations, the chapter shows how eco-evolutionary dynamics will be shaped by biological diversity: that is, different populations and species have different effects on their environment.

scholarly journals High evolutionary potential in the chemical defenses of an aposematic Heliconius butterfly

2020 ◽  
Author(s):  
Anniina L. K. Mattila ◽  
Chris D. Jiggins ◽  
Øystein H. Opedal ◽  
Gabriela Montejo-Kovacevich ◽  
Érika de Castro ◽  
...  
Keyword(s):  
Chemical Defense ◽  
Host Plant ◽  
Environmental Gradients ◽  
Common Garden ◽  
Color Pattern ◽  
Chemical Defenses ◽  
Color Patterns ◽  
Wild Populations ◽  
Evolutionary Potential ◽  
Chemical Defences

2.ABSTRACTChemical defences against predators underlie the evolution of aposematic coloration and mimicry, which represent classic examples of adaptive evolution. Yet, unlike color patterns, little is known about the evolutionary potential of chemical defences. Neotropical Heliconius butterflies exhibit incredibly diverse warning color patterns and widespread mimicry. Their larvae feed exclusively on cyanogenic Passiflora vines, can metabolize and sequester host plant toxins, as well as biosynthesize defensive cyanogenic toxins themselves. Here, we investigate variation in biosynthesized toxicity both in wild populations along environmental gradients and in common-garden broods and feeding treatments in Heliconius erato, together demonstrating considerable intraspecific variation and evolutionary potential in this important chemical defense trait. Toxicity varied markedly among wild populations from Central and South America. Within wild populations, the distribution of toxicity was consistently skewed, indicative of automimic “cheaters” that may exploit, and consequently deplete, the protection of the warning coloration. In a common-garden rearing design comprising more than 300 butterflies across 20 broods, variation in host-plant nutritional quality or cyanogen levels did not translate into differences in toxicity of butterflies feeding on these plants. Instead, toxicity had a significant heritable genetic component, in part explained by maternal inheritance. The evolvability of toxicity was high (eµ=1.55%), suggesting that toxicity can evolve rapidly. Through its link with the evolution of warning color pattern mimicry, the high evolutionary potential of cyanogenic toxicity may have facilitated diversification and ecological speciation in Heliconius, highlighting the importance of understanding the evolution of chemical defense in aposematic and mimetic species.

Evolutionary Dynamics of Metacommunities in Urbanized Landscapes

2020 ◽  
pp. 175-196 ◽  
Author(s):  
Kristien I. Brans ◽  
Lynn Govaert ◽  
Luc De Meester
Keyword(s):  
Evolutionary Dynamics ◽  
Environmental Gradients ◽  
Experimental Studies ◽  
Integrated Approach ◽  
Urban Ecosystem ◽  
Ecosystem Functions ◽  
Ecological Processes ◽  
Fully Integrated ◽  
Biological Responses ◽  
Genetic Responses

As urbanization leads to repeated, marked environmental gradients in space, it provides an ideal ‘natural’ experiment to study how evolving metacommunities, in which evolutionary and community ecological processes interact in a landscape context, respond to anthropogenic disturbances. An integrated approach that combines community data with data on genetic responses of focal taxa to urbanization is still lacking, notwithstanding the likely importance of eco-evolutionary feedbacks on urban ecosystem functions and services. Such a joint analysis is most easily achieved by focusing on shifts in trait values and their interspecific (cf. community ecology) and intraspecific components. The latter involves both non-genetic and genetic responses, and should be quantified for all dominant, abundant, or ecologically important species in the (meta)community. This chapter introduces the evolving metacommunity framework and discusses the use of cities to study how this framework can contribute to our insight into population and community responses to anthropogenic change. It discusses how this framework can enhance our capacity to predict responses to contemporary and future urbanization as well as its possible consequences for ecosystem functioning. It predicts that evolutionary trait change contributes substantially to observed trait shifts at the community level. Conversely, genetic adaptation might often be constrained by rapid changes in species composition. It explores eco-evolutionary partitioning metrics that quantify the evolutionary and ecological contributions to responses to urbanization. Finally, it provides guidelines for experimental studies on urban evolving metacommunities, and suggests directions on research that will build towards a fully integrated evolving metacommunity framework addressing biological responses to urbanization.

scholarly journals Environmental Patterns Are Imposed on the Population Structure ofEscherichia coliafter Fecal Deposition

2010 ◽  
Vol 77 (1) ◽  
pp. 211-219 ◽  
Author(s):  
Peter W. Bergholz ◽  
Jesse D. Noar ◽  
Daniel H. Buckley
Keyword(s):  
Population Structure ◽  
Genetic Structure ◽  
Environmental Gradients ◽  
Natural Populations ◽  
Genomic Diversity ◽  
Source Analysis ◽  
Ecological Processes ◽  
New Host ◽  
E Coli ◽  
Landscape Genetic

ABSTRACTThe intestinal microbeEscherichia coliis subject to fecal deposition in secondary habitats, where it persists transiently, allowing for the opportunity to colonize new hosts. Selection in the secondary habitat can be postulated, but its impact on the genomic diversity ofE. coliis unknown. Environmental selective pressure on extrahostE. colican be revealed by landscape genetic analysis, which examines the influences of dispersal processes, landscape features, and the environment on the spatiotemporal distribution of genes in natural populations. We conducted multilocus sequence analysis of 353E. coliisolates from soil and fecal samples obtained in a recreational meadow to examine the ecological processes controlling their distributions. Soil isolates, as a group, were not genetically distinct from fecal isolates, with only 0.8% of genetic variation and no fixed mutations attributed to the isolate source. Analysis of the landscape genetic structure ofE. colipopulations showed a patchy spatial structure consistent with patterns of fecal deposition. Controlling for the spatial pattern made it possible to detect environmental gradients of pH, moisture, and organic matter corresponding to the genetic structure ofE. coliin soil. Ecological distinctions amongE. colisubpopulations (i.e.,E. colireference collection [ECOR] groups) contributed to variation in subpopulation distributions. Therefore, while fecal deposition is the major predictor ofE. colidistributions on the field scale, selection imposed by the soil environment has a significant impact onE. colipopulation structure and potentially amplifies the occasional introduction of stress-tolerant strains to new host individuals by transmission through water or food.

scholarly journals Single-cell copy number variant detection reveals the dynamics and diversity of adaptation

2018 ◽  
Author(s):  
Stephanie Lauer ◽  
Grace Avecilla ◽  
Pieter Spealman ◽  
Gunjan Sethia ◽  
Nathan Brandt ◽  
...  
Keyword(s):  
Single Cell ◽  
Copy Number ◽  
Tandem Repeats ◽  
Evolutionary Dynamics ◽  
Temporal Dynamics ◽  
De Novo ◽  
Common Mechanism ◽  
Second Phase ◽  
Evolutionary Potential ◽  
Ideal System

AbstractCopy number variants (CNVs) are a pervasive, but understudied source of genetic variation and evolutionary potential. Long-term evolution experiments in chemostats provide an ideal system for studying the molecular processes underlying CNV formation and the temporal dynamics ofde novoCNVs. Here, we developed a fluorescent reporter to monitor gene amplifications and deletions at a specific locus with single-cell resolution. Using a CNV reporter in nitrogen-limited chemostats, we find thatGAP1CNVs are repeatedly generated and selected during the early stages of adaptive evolution resulting in predictable dynamics of CNV selection. However, subsequent diversification of populations defines a second phase of evolutionary dynamics that cannot be predicted. Using whole genome sequencing, we identified a variety ofGAP1CNVs that vary in size and copy number. DespiteGAP1’s proximity to tandem repeats that facilitate intrachromosomal recombination, we find that non-allelic homologous recombination (NAHR) between flanking tandem repeats occurs infrequently. Rather, breakpoint characterization revealed that for at least 50% ofGAP1CNVs, origin-dependent inverted-repeat amplification (ODIRA), a DNA replication mediated process, is the likely mechanism. We also find evidence that ODIRA generatesDUR3CNVs, indicating that it may be a common mechanism of gene amplification. We combined the CNV reporter with barcode lineage tracking and found that 103-104independent CNV-containing lineages initially compete within populations, which results in extreme clonal interference. Our study introduces a novel means of studying CNVs in heterogeneous cell populations and provides insight into the underlying dynamics of CNVs in evolution.

Phenotypic and phenological behaviours of clones of three natural populations of Atriplex halimus L. grown in a common garden

2003 ◽  
Vol 29 (2) ◽  
pp. 179-188
Author(s):  
Abdelaziz Abbad ◽  
Abdelbasset El Hadrami ◽  
Abderrazzak Benchaabane
Keyword(s):  
Natural Populations ◽  
Common Garden ◽  
Atriplex Halimus

Sex ratio and life history traits at reaching sexual maturity in the dioecious shrub Fuchsia parviflora: field and common garden experiments

2021 ◽  
pp. 1-6
Author(s):  
Jessica S. Ambriz ◽  
Clementina González ◽  
Eduardo Cuevas
Keyword(s):  
Natural Population ◽  
Sexual Maturity ◽  
Sex Ratios ◽  
Natural Populations ◽  
Common Garden ◽  
Common Garden Experiment ◽  
Trade Offs ◽  
Reproductive Biomass ◽  
Common Garden Experiments ◽  
Growth And Reproduction

Abstract Fuchsia parviflora is a dioecious shrub that depends on biotic pollination for reproduction. Previous studies suggest that the male plants produce more flowers, and male-biased sex ratios have been found in some natural populations. To assess whether the biased sex ratios found between genders in natural populations are present at the point at which plants reach sexual maturity, and to identify possible trade-offs between growth and reproduction, we performed a common garden experiment. Finally, to complement the information of the common garden experiment, we estimated the reproductive biomass allocation between genders in one natural population. Sex ratios at reaching sexual maturity in F. parviflora did not differ from 0.5, except in one population, which was the smallest seedling population. We found no differences between genders in terms of the probability of germination or flowering. When flowering began, female plants were taller than males and the tallest plants of both genders required more time to reach sexual maturity. Males produced significantly more flowers than females, and the number of flowers increased with plant height in both genders. Finally, in the natural population studied, the investment in reproductive biomass was seven-fold greater in female plants than in male plants. Our results showed no evidence of possible trade-offs between growth and reproduction. Despite the fact that female plants invest more in reproductive biomass, they were taller than the males after flowering, possibly at the expense of herbivory defence.

scholarly journals Evolutionary dynamics of spore killers.

Genetics ◽  
1993 ◽  
Vol 135 (3) ◽  
pp. 923-930 ◽  
Author(s):  
M J Nauta ◽  
R F Hoekstra
Keyword(s):  
Life Cycle ◽  
Segregation Distortion ◽  
Population Genetic ◽  
Field Data ◽  
Evolutionary Dynamics ◽  
Natural Populations ◽  
Additional Advantage ◽  
Genetic Modeling ◽  
Spore Killing ◽  
Ascospore Formation

Abstract Spore killing in ascomycetes is a special form of segregation distortion. When a strain with the Killer genotype is crossed to a Sensitive type, spore killing is expressed by asci with only half the number of ascospores as usual, all surviving ascospores being of the Killer type. Using population genetic modeling, this paper explores conditions for invasion of Spore killers and for polymorphism of Killers, Sensitives and Resistants (which neither kill, nor get killed), as found in natural populations. The models show that a population with only Killers and Sensitives can never be stable. The invasion of Killers and stable polymorphism only occur if Killers have some additional advantage during the process of spore killing. This may be due to the effects of local sib competition or some kind of "heterozygous" advantage in the stage of ascospore formation or in the short diploid stage of the life cycle. This form of segregation distortion appears to be essentially different from other, well-investigated forms, and more field data are needed for a better understanding of spore killing.

scholarly journals Natural variation in yolk fatty acids, but not androgens, predicts offspring fitness in a wild bird

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Lucia Mentesana ◽  
Martin N. Andersson ◽  
Stefania Casagrande ◽  
Wolfgang Goymann ◽  
Caroline Isaksson ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Polyunsaturated Fatty Acids ◽  
Maternal Effects ◽  
Natural Variation ◽  
De Novo ◽  
Natural Populations ◽  
Egg Laying ◽  
Interactive Effects ◽  
Free Living ◽  
Offspring Fitness

Abstract Background In egg-laying animals, mothers can influence the developmental environment and thus the phenotype of their offspring by secreting various substances into the egg yolk. In birds, recent studies have demonstrated that different yolk substances can interactively affect offspring phenotype, but the implications of such effects for offspring fitness and phenotype in natural populations have remained unclear. We measured natural variation in the content of 31 yolk components known to shape offspring phenotypes including steroid hormones, antioxidants and fatty acids in eggs of free-living great tits (Parus major) during two breeding seasons. We tested for relationships between yolk component groupings and offspring fitness and phenotypes. Results Variation in hatchling and fledgling numbers was primarily explained by yolk fatty acids (including saturated, mono- and polyunsaturated fatty acids) - but not by androgen hormones and carotenoids, components previously considered to be major determinants of offspring phenotype. Fatty acids were also better predictors of variation in nestling oxidative status and size than androgens and carotenoids. Conclusions Our results suggest that fatty acids are important yolk substances that contribute to shaping offspring fitness and phenotype in free-living populations. Since polyunsaturated fatty acids cannot be produced de novo by the mother, but have to be obtained from the diet, these findings highlight potential mechanisms (e.g., weather, habitat quality, foraging ability) through which environmental variation may shape maternal effects and consequences for offspring. Our study represents an important first step towards unraveling interactive effects of multiple yolk substances on offspring fitness and phenotypes in free-living populations. It provides the basis for future experiments that will establish the pathways by which yolk components, singly and/or interactively, mediate maternal effects in natural populations.

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