scholarly journals A transplantation experiment yields no evidence for phenotypic plasticity in shell band width in Cepaea nemoralis

2020 ◽  
Author(s):  
Menno Schilthuizen ◽  
Ruth K. Scheid ◽  
Lia J. J. den Daas
Keyword(s):  
Phenotypic Plasticity ◽  
Evolutionary Biology ◽  
Band Width ◽  
Model Species ◽  
Habitat Types ◽  
Colour Variation ◽  
Cepaea Nemoralis ◽  
Transplantation Experiment ◽  
The Common ◽  
Spiral Bands

AbstractThe common European grove snail, Cepaea nemoralis (Helicidae), has been a model species in genetics and evolutionary biology for over a century thanks largely to its genetic shell colour polymorphism. Although most aspects of its shell colour variation are known to be purely genetic, with little or no phenotypic plasticity involved, the width of the spiral bands has been suspected to display a certain amount of plasticity. To test this, we conducted a transplantation experiment, in which 548 growing banded snails were marked and transplanted, either within the same habitat (open or closed vegetation, displaying 19% and 61% band fusion, respectively) or between habitat types. The numbers recaptured were low: 8%, 5% after removal of individuals that had not grown. Based on these samples, we did not find any substantial influence of transplantation on band width.

The Nature and Analysis of Phenotypic Transitions

2003 ◽  
Author(s):  
Mary Jane West-Eberhard
Keyword(s):  
Evolutionary Biology ◽  
Adopted Children ◽  
Psychological Traits ◽  
Origin Of Species ◽  
Classical Mythology ◽  
Biological Parents ◽  
Novel Traits ◽  
Famous Book ◽  
The Common ◽  
Vertebrate Eye

Part II is about origins: how do new traits arise from old phenotypes? People of all ages are fascinated by the question of origins. Origins are the common concern of evolutionists and creationists, of ethnic historians, of Mormon geneologists and the Daughters of the American Revolution, of adopted children searching for their biological parents— indeed, of all who have wondered where Johnny got his patience, his sense of humor, or his big nose. Darwin was a clever publicist when he titled his most famous book The Origin of Species. He touched deep human chords by discussing not only the origin of species but the origin of marvellously complex morphological and psychological traits—specialized limbs, sexual behavior, intelligence, heroism, and the vertebrate eye, to mention just a few. Research on selection and adaptation may tell us why a trait persisted and spread, but it will not tell us where a trait came from. This is why evolutionary biology inevitably intersects with developmental biology, and why satisfactory explanations of ultimate (evolutionary) causation must always include both proximate causes and the study of selection. Novel traits originate via the transformation of ancestral phenotypes during development. This transformational aspect of evolutionary change has been oddly neglected in modern evolutionary biology, even though it is an integral part of human curiosity about origins in other fields. From classical mythology to modern-day childrens’ books, origins are explained in terms of transformations of the phenotype, alongside attention to developmental mechanisms and adaptive functions. Consider this excerpt from The Apeman’s Secret (Dixon, 1980), a Hardy Boys adventure book: . . . [T]he Apeman hated cruelty of any kind. Whenever he saw crooks or villians do something nasty to a helpless victim, he would fly into a rage. This would change his body chemistry and cause him to revert to the savage state. . . .

The Diets of the Large Rock-Rat, Zyzomys Woodwardi, and the Common Rock-Rat, Z. Argurus (Rodentia: Muridae).

1985 ◽  
Vol 12 (1) ◽  
pp. 19 ◽  
Author(s):  
RJ Begg ◽  
CJ Dunlop
Keyword(s):  
Plant Species ◽  
Dry Season ◽  
Food Plants ◽  
Food Store ◽  
Habitat Types ◽  
Faecal Samples ◽  
Wide Range ◽  
Reference Collection ◽  
The Common

The diets of Zyzomys woodwardi from two habitat types and Z, argurus from one of them were investigated by microanalysis of faecal samples which were collected over a 12-month period. Forty-three species of food plants were identified. Differences were found in the diets of Z. woodwardi from the two habitat types, according to the different food plants available; the two species living sympatrically shared 52% of plant species identified. Both species ate a wide range of seed sizes, according to what was available seasonally. Hard-shelled seeds remained on the ground as a ready food store for much of the year but grasses were utilized only in the dry season, as they rotted or germinated during the wet. The technique used produced fragments that were identifiable, when the reference collection was sufficiently extensive, but was not suitable for detailed quantitative comparisons and was extremely time-consuming.

scholarly journals A simple index to quantify and compare the magnitude of intraspecific geographic plumage colour variation in typical antbirds (Aves: Passeriformes: Thamnophilidae)

2020 ◽  
Vol 130 (2) ◽  
pp. 239-246
Author(s):  
Rafael S Marcondes ◽  
Robb T Brumfield
Keyword(s):  
Geographic Variation ◽  
Phenotypic Variation ◽  
Evolutionary Biology ◽  
Phylogeographic Structure ◽  
Plumage Colour ◽  
Colour Space ◽  
Colour Variation ◽  
Simple Index ◽  
High Prevalence ◽  
Variable Species

Abstract Intraspecific geographic phenotypic variation is a crucial theme in evolutionary biology. Comparing its magnitude across species can provide insights into its ecological and genetic correlates. Here, we developed an index, which we dub the V index, to quantify intraspecific plumage colour variation in typical antbirds (Thamnophilidae), a family which has long interested ornithologists due to a high prevalence of intraspecific variation. The V index is based on a bivariate colour space defined by brightness and redness. Its value for each species equals the mean area occupied by each of its subspecies in that colour space, divided by the area of the species. Lower values indicate greater intraspecific geographic variation. Based on this index, Thamnophilus caerulescens (Variable Antshrike) was exceptionally geographically variable compared to other thamnophilids, as previously suggested based on qualitative evidence. In general, we found that the most variable species had disjunct distributions and deep phylogeographic structure, suggesting an effect of historical population dynamics in producing geographic variation. The V index can be adapted for use with other taxa, traits, and taxonomic levels, and we expect it will instigate novel ways of thinking about phenotypic variation in birds and other animals.

Phenotypic Plasticity of Growth and Survival in the Common Lizard Lacerta vivipara

10.2307/5676 ◽  
1996 ◽  
Vol 65 (6) ◽  
pp. 781 ◽  
Author(s):  
Gabriele Sorci ◽  
Jean Clobert ◽  
Sophie Belichon
Keyword(s):  
Phenotypic Plasticity ◽  
Growth And Survival ◽  
Common Lizard ◽  
The Common ◽  
Lacerta Vivipara

scholarly journals Inducible competitors and adaptive diversification

2013 ◽  
Vol 59 (4) ◽  
pp. 537-552 ◽  
Author(s):  
Beren W. Robinson ◽  
David W. Pfennig
Keyword(s):  
Phenotypic Plasticity ◽  
Resource Use ◽  
Evolutionary Biology ◽  
The Other ◽  
Competitive Interactions ◽  
Adaptive Plasticity ◽  
Evolutionary Divergence ◽  
Phenotypic Differences ◽  
Adaptive Diversification ◽  
Divergent Natural Selection

Abstract Identifying the causes of diversification is central to evolutionary biology. The ecological theory of adaptive diversification holds that the evolution of phenotypic differences between populations and species—and the formation of new species—stems from divergent natural selection, often arising from competitive interactions. Although increasing evidence suggests that phenotypic plasticity can facilitate this process, it is not generally appreciated that competitively mediated selection often also provides ideal conditions for phenotypic plasticity to evolve in the first place. Here, we discuss how competition plays at least two key roles in adaptive diversification depending on its pattern. First, heterogenous competition initially generates heterogeneity in resource use that favors adaptive plasticity in the form of “inducible competitors”. Second, once such competitively induced plasticity evolves, its capacity to rapidly generate phenotypic variation and expose phenotypes to alternate selective regimes allows populations to respond readily to selection favoring diversification, as may occur when competition generates steady diversifying selection that permanently drives the evolutionary divergence of populations that use different resources. Thus, competition plays two important roles in adaptive diversification—one well-known and the other only now emerging—mediated through its effect on the evolution of phenotypic plasticity.

scholarly journals Sex and Speciation: Drosophila Reproductive Tract Proteins— Twenty Five Years Later

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Rama Singh ◽  
Santosh Jagadeeshan
Keyword(s):  
Evolutionary Biology ◽  
Reproductive Tract ◽  
Evolutionary Dynamics ◽  
Molecular Genetic ◽  
Rapid Evolution ◽  
2D Electrophoresis ◽  
Large Area ◽  
Genomic Studies ◽  
Molecular Genetic Variation ◽  
The Common

The protein electrophoresis revolution, nearly fifty years ago, provided the first glimpse into the nature of molecular genetic variation within and between species and showed that the amount of genetic differences between newly arisen species was minimal. Twenty years later, 2D electrophoresis showed that, in contrast to general gene-enzyme variation, reproductive tract proteins were less polymorphic within species but highly diverged between species. The 2D results were interesting and revolutionary, but somewhat uninterpretable because, at the time, rapid evolution and selective sweeps were not yet part of the common vocabulary of evolutionary biologists. Since then, genomic studies of sex and reproduction-related (SRR) genes have grown rapidly into a large area of research in evolutionary biology and are shedding light on a number of phenomena. Here we review some of the major and current fields of research that have greatly contributed to our understanding of the evolutionary dynamics and importance of SRR genes and genetic systems in understanding reproductive biology and speciation.

scholarly journals An evaluation of pool-sequencing transcriptome-based exon capture for population genomics in non-model species

2019 ◽  
Author(s):  
Emeline Deleury ◽  
Thomas Guillemaud ◽  
Aurélie Blin ◽  
Eric Lombaert
Keyword(s):  
Evolutionary Biology ◽  
High Throughput Sequencing ◽  
Harmonia Axyridis ◽  
Population Genomics ◽  
De Novo ◽  
Cost Effective ◽  
Allele Frequencies ◽  
Technical Solution ◽  
Model Species ◽  
Exon Capture

AbstractExon capture coupled to high-throughput sequencing constitutes a cost-effective technical solution for addressing specific questions in evolutionary biology by focusing on expressed regions of the genome preferentially targeted by selection. Transcriptome-based capture, a process that can be used to capture the exons of non-model species, is use in phylogenomics. However, its use in population genomics remains rare due to the high costs of sequencing large numbers of indexed individuals across multiple populations. We evaluated the feasibility of combining transcriptome-based capture and the pooling of tissues from numerous individuals for DNA extraction as a cost-effective, generic and robust approach to estimating the variant allele frequencies of any species at the population level. We designed capture probes for ∼5 Mb of chosen de novo transcripts from the Asian ladybird Harmonia axyridis (5,717 transcripts). We called ∼300,000 bi-allelic SNPs for a pool of 36 non-indexed individuals. Capture efficiency was high, and pool-seq was as effective and accurate as individual-seq for detecting variants and estimating allele frequencies. Finally, we also evaluated an approach for simplifying bioinformatic analyses by mapping genomic reads directly to targeted transcript sequences to obtain coding variants. This approach is effective and does not affect the estimation of SNP allele frequencies, except for a small bias close to some exon ends. We demonstrate that this approach can also be used to predict the intron-exon boundaries of targeted de novo transcripts, making it possible to abolish genotyping biases near exon ends.

Why Cooperate?

2009 ◽  
Author(s):  
Thomas N. Sherratt ◽  
David M. Wilkinson
Keyword(s):  
Kin Selection ◽  
Evolutionary Biology ◽  
Presidential Address ◽  
Natural World ◽  
Selfish Gene ◽  
The Social ◽  
Self Interest ◽  
The World ◽  
Vampire Bats ◽  
The Common

An altruistic act is one in which an individual incurs a cost that results in a benefit to others. Giving money or time to those less fortunate than ourselves is one example, as is giving up one’s seat on a bus. At first, one might consider such behaviour hopelessly naive in a world in which natural selection seemingly rewards selfishness in the competitive struggle for existence. As the saying goes, ‘nice guys finish last’. Yet examples of apparent altruism are commonplace. Meerkats will spend hours in the baking sun keeping lookout for predators that might attack their colony mates. Vampire bats will regurgitate blood to feed their starving roost fellows, while baboons will take the time and effort to groom other baboons. Some individuals, such as honeybee workers, forego their own reproduction to help their queen and will even die in her defence. The common gut bacterium Escherichia coli commits suicide when it is infected by a bacteriophage, thereby protecting its clones from being infected. If helping incurs a cost, then surely an individual that accepts a cooperative act yet gives nothing in return would do better than cooperators? What, then, allows these cases of apparent altruism to persist? In his last presidential address to the Royal Society of London in November 2005, Robert M. May argued, ‘The most important unanswered question in evolutionary biology, and more generally in the social sciences, is how cooperative behaviour evolved and can be maintained’. In this chapter, we document a number of examples of cooperation in the natural world and ask how it is maintained despite the obvious evolutionary pressure to ‘cheat’. We will see that, while it is tempting to see societies as some form of higher organism, to fully understand cooperation, it helps to take a more reductionist view of the world, frequently a gene-centred perspective. Indeed, thinking about altruism has led to one of the greatest triumphs of the ‘selfish gene’ approach, namely the theory of kin selection. Ultimately, as the quote from Mandeville indicates, we will see that cooperation frequently arises simply out of pure self-interest—it just so happens that individuals (or, more precisely, genes) in the business of helping themselves sometimes help others.

scholarly journals The power of associative learning and the ontogeny of optimal behaviour

2016 ◽  
Vol 3 (11) ◽  
pp. 160734 ◽  
Author(s):  
Magnus Enquist ◽  
Johan Lind ◽  
Stefano Ghirlanda
Keyword(s):  
Associative Learning ◽  
Conditioned Reinforcement ◽  
Evolutionary Biology ◽  
Self Control ◽  
Common Belief ◽  
Genetic Evolution ◽  
Current Opinion ◽  
The Common ◽  
Optimal Behaviour ◽  
Behavioural Strategies

Behaving efficiently (optimally or near-optimally) is central to animals' adaptation to their environment. Much evolutionary biology assumes, implicitly or explicitly, that optimal behavioural strategies are genetically inherited, yet the behaviour of many animals depends crucially on learning. The question of how learning contributes to optimal behaviour is largely open. Here we propose an associative learning model that can learn optimal behaviour in a wide variety of ecologically relevant circumstances. The model learns through chaining, a term introduced by Skinner to indicate learning of behaviour sequences by linking together shorter sequences or single behaviours. Our model formalizes the concept of conditioned reinforcement (the learning process that underlies chaining) and is closely related to optimization algorithms from machine learning. Our analysis dispels the common belief that associative learning is too limited to produce ‘intelligent’ behaviour such as tool use, social learning, self-control or expectations of the future. Furthermore, the model readily accounts for both instinctual and learned aspects of behaviour, clarifying how genetic evolution and individual learning complement each other, and bridging a long-standing divide between ethology and psychology. We conclude that associative learning, supported by genetic predispositions and including the oft-neglected phenomenon of conditioned reinforcement, may suffice to explain the ontogeny of optimal behaviour in most, if not all, non-human animals. Our results establish associative learning as a more powerful optimizing mechanism than acknowledged by current opinion.

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