scholarly journals Is the behavioural divergence between range-core and range-edge populations of cane toads ( Rhinella marina ) due to evolutionary change or developmental plasticity?

2017 ◽  
Vol 4 (10) ◽  
pp. 170789 ◽  
Author(s):  
Jodie Gruber ◽  
Gregory Brown ◽  
Martin J. Whiting ◽  
Richard Shine
Keyword(s):  
Developmental Plasticity ◽  
Leading Edge ◽  
Common Garden ◽  
Phenotypic Traits ◽  
Genetic Traits ◽  
Rhinella Marina ◽  
Range Edge ◽  
In Captivity ◽  
Edge Populations ◽  
Range Core

Individuals at the leading edge of expanding biological invasions often show distinctive phenotypic traits, in ways that enhance their ability to disperse rapidly and to function effectively in novel environments. Cane toads ( Rhinella marina ) at the invasion front in Australia exhibit shifts in morphology, physiology and behaviour (directionality of dispersal, boldness, risk-taking). We took a common-garden approach, raising toads from range-core and range-edge populations in captivity, to see if the behavioural divergences observed in wild-caught toads are also evident in common-garden offspring. Captive-raised toads from the invasion vanguard population were more exploratory and bolder (more prone to ‘risky’ behaviours) than toads from the range core, which suggests that these are evolved, genetic traits. Our study highlights the importance of behaviour as being potentially adaptive in invasive populations and adds these behavioural traits to the increasing list of phenotypic traits that have evolved rapidly during the toads' 80-year spread through tropical Australia.

scholarly journals The accelerating anuran: evolution of locomotor performance in cane toads ( Rhinella marina , Bufonidae) at an invasion front

2020 ◽  
Vol 287 (1938) ◽  
pp. 20201964 ◽  
Author(s):  
Cameron M. Hudson ◽  
Marta Vidal-García ◽  
Trevor G. Murray ◽  
Richard Shine
Keyword(s):  
Morphological Traits ◽  
High Speed ◽  
Morphological Changes ◽  
Locomotor Performance ◽  
Rhinella Marina ◽  
Invasion Front ◽  
In Captivity ◽  
Tropical Australia ◽  
Range Core ◽  
Locomotor Ability

As is common in biological invasions, the rate at which cane toads ( Rhinella marina ) have spread across tropical Australia has accelerated through time. Individuals at the invasion front travel further than range-core conspecifics and exhibit distinctive morphologies that may facilitate rapid dispersal. However, the links between these morphological changes and locomotor performance have not been clearly documented. We used raceway trials and high-speed videography to document locomotor traits (e.g. hop distances, heights, velocities, and angles of take-off and landing) of toads from range-core and invasion-front populations. Locomotor performance varied geographically, and this variation in performance was linked to morphological features that have evolved during the toads' Australian invasion. Geographical variation in morphology and locomotor ability was evident not only in wild-caught animals, but also in individuals that had been raised under standardized conditions in captivity. Our data thus support the hypothesis that the cane toad's invasion across Australia has generated rapid evolutionary shifts in dispersal-relevant performance traits, and that these differences in performance are linked to concurrent shifts in morphological traits.

scholarly journals On the role of sex differences for evolution in heterogeneous and changing fitness landscapes: insights from pygmy grasshoppers

2018 ◽  
Vol 373 (1757) ◽  
pp. 20170429 ◽  
Author(s):  
Anders Forsman
Keyword(s):  
Sex Differences ◽  
Developmental Plasticity ◽  
Common Garden ◽  
Field Studies ◽  
Fitness Landscapes ◽  
Phenotypic Traits ◽  
Environment Interaction ◽  
Local Adaptations ◽  
Changing Environments

Much research has been devoted to study evolution of local adaptations by natural selection, and to explore the roles of neutral processes and developmental plasticity for patterns of diversity among individuals, populations and species. Some aspects, such as evolution of adaptive variation in phenotypic traits in stable environments, and the role of plasticity in predictable changing environments, are well understood. Other aspects, such as the role of sex differences for evolution in spatially heterogeneous and temporally changing environments and dynamic fitness landscapes, remain elusive. An increased understanding of evolution requires that sex differences in development, physiology, morphology, life-history and behaviours are more broadly considered. Studies of selection should take into consideration that the relationships linking phenotypes to fitness may vary not only according to environmental conditions but also differ between males and females. Such opposing selection, sex-by-environment interaction effects of selection and sex-specific developmental plasticity can have consequences for population differentiation, local adaptations and for the dynamics of polymorphisms. Integrating sex differences in analytical frameworks and population comparisons can therefore illuminate neglected evolutionary drivers and reconcile unexpected patterns. Here, I illustrate these issues using empirical examples from over 20 years of research on colour polymorphic Tetrix subulata and Tetrix undulata pygmy grasshoppers, and summarize findings from observational field studies, manipulation experiments, common garden breeding experiments and population genetics studies. This article is part of the theme issue ‘Linking local adaptation with the evolution of sex differences’.

scholarly journals Genetic variability and the ecology of geographic range: a test of the central-marginal hypothesis in Australian scincid lizards

2021 ◽  
Author(s):  
Sonal Singhal ◽  
John Wrath ◽  
Daniel Rabosky
Keyword(s):  
Genetic Diversity ◽  
Genomic Dataset ◽  
Range Edge ◽  
Edge Populations ◽  
Demographic Shifts ◽  
Range Core ◽  
Reduced Density ◽  
Verbal Model ◽  
Significant Support

For many species, both local abundance and regional occupancy are highest near the center of their geographic distributions. One hypothesis for this pattern is that niche suitability declines with increasing distance from a species geographic center, such that populations near range margins are characterized by reduced density and increased patchiness. In these smaller edge populations, genetic drift is more powerful, leading to the loss of genetic diversity. This simple verbal model has been formalized as the central-marginal hypothesis, which predicts that core populations should have greater genetic diversity than edge populations. However, demographic shifts over time can generate a similar pattern. For example, in species with expanding ranges, populations at the range edge experience serial founder effects, creating a gradient of declining genetic diversity from the range core to edge. Testing the central-marginal hypothesis properly thus requires us to consider the confounding role of historical demography. Here, we account for the role of history in testing the central-marginal hypothesis using a genomic dataset of 25 species-level taxa of Australian skink lizards (genus: Ctenotus and Lerista). We found support for the central-marginal hypothesis in 16 of our 25 taxa, of which eight taxa recovered significant support. Unexpectedly, species with the strongest evidence for range expansion were the least likely to follow predictions of the central-marginal hypothesis. The majority of these species had range expansions that originated at the range edge, which led to lower genetic diversity at the range edge compared to the core, contrary to the central-marginal hypothesis.

Hormones and Behavior

2019 ◽  
pp. 11-26
Author(s):  
Maren N. Vitousek ◽  
Laura A. Schoenle
Keyword(s):  
Life History ◽  
Life Histories ◽  
Life History Traits ◽  
Developmental Plasticity ◽  
Endocrine System ◽  
Phenotypic Traits ◽  
Social Environments ◽  
Trade Offs ◽  
And Behavior

Hormones mediate the expression of life history traits—phenotypic traits that contribute to lifetime fitness (i.e., reproductive timing, growth rate, number and size of offspring). The endocrine system shapes phenotype by organizing tissues during developmental periods and by activating changes in behavior, physiology, and morphology in response to varying physical and social environments. Because hormones can simultaneously regulate many traits (hormonal pleiotropy), they are important mediators of life history trade-offs among growth, reproduction, and survival. This chapter reviews the role of hormones in shaping life histories with an emphasis on developmental plasticity and reversible flexibility in endocrine and life history traits. It also discusses the advantages of studying hormone–behavior interactions from an evolutionary perspective. Recent research in evolutionary endocrinology has provided insight into the heritability of endocrine traits, how selection on hormone systems may influence the evolution of life histories, and the role of hormonal pleiotropy in driving or constraining evolution.

scholarly journals EVOLUTION OF DNA SEQUENCING METHODS AND PROSPECTS FOR THEIR USE IN FORENSIC DNA EXAMINATION

2020 ◽  
Vol 11 (87) ◽  
Author(s):  
Zhanna Bazyliuk ◽  
Keyword(s):  
Dna Sequencing ◽  
Molecular Genetic ◽  
Genetic Research ◽  
Snp Markers ◽  
Degraded Dna ◽  
Phenotypic Traits ◽  
Nucleotide Polymorphisms ◽  
Biological Origin ◽  
Genetic Traits ◽  
Str Loci

The study of the human genome makes it possible to use genetic information to identify individual traits, diagnosis of diseases and forecasting and prevention of their development, promotes a personal approach when choosing treatment methods; population research, ethnogenesis and evolutionary processes. Introduction of DNA sequencing methods in domestic genetic fingerprinting will contribute to a more informative establishment of human genetic traits. The main purpose of molecular genetic research is to establish the genetic features of missing people, their relatives, to conduct paternity, to identify traces of biological origin and their identification. This article talks about the gradual development of DNA sequencing technology, which is conventionally divided into three types. The first type includes sequencing using capillary electrophoresis and pyrosequencing. The second type is high-throughput pyrosequencing, semiconductor, cyclic ligase, and the use of fluorescently labeled precursors, based on the sequencing of millions of DNA fragments simultaneously. The third stage includes methods that do not require prior sample preparation. These are methods of nanoporous sequencing, sequencing of one molecule, one-molecular sequencing. Today, each of the sequencing methods is aimed at performing different tasks. A number of methods are promising in the field of molecular-genetic examination. In world jurisprudence, sequencing is implemented mainly with the help of devices - Illumina’s, MiSeq FGx, Ion Torrent PGM from ThermoFisher and Ion S5. Research in forensic expertise of single nucleotide polymorphisms (SNP), sequencing of STR-loci and mitochondrial DNA, STR-loci and SNP-markers of the Y chromosome, will provide a high level of information, determination of human phenotypic traits, the possibility of establishing genetic traits from significantly degraded DNA. This article deals with modern problems of identification of human genetic traits and the prospect of introduction of the newest methods of sequencing for their qualitative and complete establishment.

scholarly journals Genetic patterns in range-edge populations of Vaccinium species from the central Balkans: implications on conservation prospects and sustainable usage

Silva Fennica ◽  
2015 ◽  
Vol 49 (4) ◽  
Author(s):  
Ivana Bjedov ◽  
Dragica Obratov–Petković ◽  
Danijela Mišić ◽  
Branislav Šiler ◽  
Jelena Aleksic
Keyword(s):  
Range Edge ◽  
Genetic Patterns ◽  
Edge Populations ◽  
Sustainable Usage

scholarly journals Plant Phenotypic Traits Eventually Shape Its Microbiota: A Common Garden Test

2018 ◽  
Vol 9 ◽  
Author(s):  
Yunshi Li ◽  
Xiukun Wu ◽  
Tuo Chen ◽  
Wanfu Wang ◽  
Guangxiu Liu ◽  
...  
Keyword(s):  
Common Garden ◽  
Phenotypic Traits

Assessment

2003 ◽  
Author(s):  
Mary Jane West-Eberhard
Keyword(s):  
Evolutionary Biology ◽  
Developmental Plasticity ◽  
Phenotypic Traits ◽  
Phase Polymorphism ◽  
Aesthetic Sense ◽  
Adaptive Assessment ◽  
Important Barrier ◽  
Symbiotic Microorganism ◽  
Adaptive Developmental Plasticity ◽  
Adaptive Switch

A book on developmental plasticity needs a chapter on assessment, if only to show that adaptive environmental assessment occurs. Skepticism regarding the ability of nonhuman organisms to assess conditions well enough to make adaptive decisions has a long history in evolutionary biology, and it has been an important barrier to understanding the evolution of adaptive developmental plasticity. It is worth briefly reviewing this history in order to understand certain preconceptions about assessment that still persist. In the nineteenth century, critics of Darwin’s theory of sexual selection (Darwin, 1871) balked at the idea of an “aesthetic sense” in lowly creatures that would enable female choice of mates (representative papers are reprinted and discussed in Bajema, 1984). Later, the barrier persisted for other reasons. Even though naturalists routinely used the condition-appropriate expression of phenotypic traits to support adaptation hypotheses—a practice that assumes adaptive assessment of conditions as it is defined here—theoretically inclined biologists paid little attention to the question of facultatively expressed traits. Part of the difficulty lay in the problem of explaining how adaptive assessment could evolve within the framework of conventional genetics. Theodosius Dobzhansky, one of the twentieth century’s leading evolutionary biologists, acknowledged this unresolved problem in remarks following a lecture by J. S. Kennedy on the phase polyphenisms of migratory locusts (Kennedy, 1961). Dobzhansky referred to the “challenge to a geneticist” of explaining the adaptive switch between the sedentary and the migratory phenotypes of the locusts, which had been shown to be largely independent of genotype. He suggested that an extrachromosomal factor may be involved, a symbiotic microorganism that acts as a “plasmagene” whose multiplication would eventually stimulate phase change. Although Dobzhansky’s proposal was no more preposterous than some of the regulatory devices that have actually been discovered, Kennedy (1961) minced no words in his reply to this suggestion: . . . [W]e need not feel obliged to invoke a second organism to explain [phase polymorphism] unless we are reluctant to concede an important part to the environment as well as to heredity in moulding development. . . .

Conserved growth rate and age structure of Xenopus laevis in the edge and core of an expanding population

2019 ◽  
Vol 128 (1) ◽  
pp. 122-129 ◽  
Author(s):  
Julien Courant ◽  
Layla Adil ◽  
Barbara De Kegel ◽  
Dominique Adriaens ◽  
Anthony Herrel
Keyword(s):  
Growth Rate ◽  
Xenopus Laevis ◽  
Age Structure ◽  
Reproductive Investment ◽  
Individual Growth ◽  
Evolutionary Mechanisms ◽  
Range Edge ◽  
Investment In Reproduction ◽  
Range Core ◽  
Expanding Population

Abstract Invasive species represent a unique opportunity to study the evolutionary mechanisms driving range expansions. Although range expansion is expected to be associated with increased reproduction and dispersal at the range edge, Xenopus laevis seems to decrease its reproductive investment and to enhance dispersal at the range edge. Evidence of increased dispersal at the edge of expanding populations occurring simultaneously with a faster growth rate has been reported for other organisms. Here, we focused on the growth rate and age structure at the range edge vs. the range core in an expanding population of X. laevis. We used skeletochronology to characterize the age of 250 individuals captured at the range core and edge of this expanding population. Using the Von Bertalanffy equation, we then compared individual growth rates between locations. We found no significant changes in growth rate or age structure between edge and core samples. This result suggests that the reduced investment in reproduction recorded in another study at the range edge might compensate for the increased dispersal without impacting growth in this population. This implies that the resource allocation in an expanding population might thus be more diverse than commonly assumed.

scholarly journals Autumn freeze-thaw events carry over to depress late-winter reproductive performance in Canada jays

2019 ◽  
Vol 6 (4) ◽  
pp. 181754 ◽  
Author(s):  
Alex O. Sutton ◽  
Dan Strickland ◽  
Nikole E. Freeman ◽  
Amy E. M. Newman ◽  
D. Ryan Norris
Keyword(s):  
Climate Change ◽  
Reproductive Performance ◽  
Climatic Conditions ◽  
Late Winter ◽  
Freeze Thaw ◽  
Range Edge ◽  
Food Caching ◽  
Nestling Condition ◽  
Edge Populations ◽  
Carry Over

Evidence suggests that range-edge populations are highly vulnerable to the impacts of climate change, but few studies have examined the specific mechanisms that are driving observed declines. Species that store perishable food for extended periods of time may be particularly susceptible to environmental change because shifts in climatic conditions could accelerate the natural degradation of their cached food. Here, we use 40 years of breeding data from a marked population of Canada jays ( Perisoreus canadensis ) located at the southern edge of their range in Algonquin Provincial Park, Ontario, to examine whether climatic conditions prior to breeding carry over to influence reproductive performance. We found that multiple measures of Canada jay reproductive performance (brood size, nest success and nestling condition) in the late winter were negatively correlated with the number of freeze–thaw events the previous autumn. Our results suggest that freeze–thaw events have a significant detrimental impact on the quality and/or quantity of cached food available to Canada jays. Future increases in such events, caused by climate change, could pose a serious threat to Canada jays and other food caching species that store perishable foods for long periods of time.

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