scholarly journals Natural selection in the origin: how does selection act on snails’ shell colour in the source of a diversified population?

2021 ◽  
Author(s):  
Shun Ito ◽  
Takahiro Hirano ◽  
Satoshi Chiba ◽  
Junji Konuma
Keyword(s):  
Natural Selection ◽  
Adaptive Radiation ◽  
Land Snail ◽  
Camera Traps ◽  
Disruptive Selection ◽  
Source Population ◽  
Apodemus Speciosus ◽  
Divergent Natural Selection ◽  
Trail Camera ◽  
Phenotypic Diversification

The mechanisms of adaptive radiation with phenotypic diversification and further adaptive speciation have been becoming clearer through a number of studies. Natural selection is one of the primary factors that contribute to these mechanisms. It has been demonstrated that divergent natural selection acts on a certain trait in adaptive radiation. However, it is not often known how natural selection acts on the source of a diversified population, although it has been detected in phylogenetic studies. Our study demonstrates how selection acts on a trait in a source population of diversified population using the Japanese land snail Euhadra peliomphala simodae. This snail’s shell colour has diversified due to disruptive selection after migration from the mainland to islands. We used trail-camera traps to identify the cause of natural selection on both the mainland and an island. We then conducted a mark-recapture experiment on the mainland to detect natural selection and compare the shape and strength of it to previous study in an island. In total, we captured and marked around 1,700 snails, and some of them were preyed on by an unknown predator. The trail-camera traps showed that the predator is the large Japanese field mouse Apodemus speciosus, but this predation did not correlate with shell colour. A Bayesian approach showed that the stabilising selection from factors other than predation acted on shell colour. Our results suggest that natural selection was changed by migration, which could explain the ultimate cause of phenotypic diversification in adaptive radiation that was not due to predation.

scholarly journals Evolution of genetic variance during adaptive radiation

2017 ◽  
Author(s):  
Greg M. Walter ◽  
J. David Aguirre ◽  
Mark W. Blows ◽  
Daniel Ortiz-Barrientos
Keyword(s):  
Natural Selection ◽  
Adaptive Radiation ◽  
Genetic Variance ◽  
Allelic Variation ◽  
Genetic Correlations ◽  
Leaf Traits ◽  
Adaptive Divergence ◽  
Ecotypic Differentiation ◽  
Divergent Natural Selection ◽  
Rapid Divergence

AbstractGenetic correlations between traits can bias adaptation away from optimal phenotypes and constrain the rate of evolution. If genetic correlations between traits limit adaptation to contrasting environments, rapid adaptive divergence across a heterogeneous landscape may be difficult. However, if genetic variance can evolve and align with the direction of natural selection, then abundant allelic variation can promote rapid divergence during adaptive radiation. Here, we explored adaptive divergence among ecotypes of an Australian native wildflower by quantifying divergence in multivariate phenotypes of populations that occupy four contrasting environments. We investigated differences in multivariate genetic variance underlying morphological traits and examined the alignment between divergence in phenotype and divergence in genetic variance. We found that divergence in mean multivariate phenotype has occurred along two major axes represented by different combinations of plant architecture and leaf traits. Ecotypes also showed divergence in the level of genetic variance in individual traits, and the multivariate distribution of genetic variance among traits. Divergence in multivariate phenotypic mean aligned with divergence in genetic variance, with most of the divergence in phenotype among ecotypes associated with a change in trait combinations that had substantial levels of genetic variance in each ecotype. Overall, our results suggest that divergent natural selection acting on high levels of standing genetic variation might fuel ecotypic differentiation during the early stages of adaptive radiation.

scholarly journals Ecological Divergence and the Origins of Intrinsic Postmating Isolation with Gene Flow

2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
Aneil F. Agrawal ◽  
Jeffrey L. Feder ◽  
Patrik Nosil
Keyword(s):  
Linkage Disequilibrium ◽  
Gene Flow ◽  
Natural Selection ◽  
Theoretical Models ◽  
Ecological Speciation ◽  
Divergent Selection ◽  
Postmating Isolation ◽  
Divergent Natural Selection ◽  
Mathematical Exploration ◽  
Neutral Gene

The evolution of intrinsic postmating isolation has received much attention, both historically and in recent studies of speciation genes. Intrinsic isolation often stems from between-locus genetic incompatibilities, where alleles that function well within species are incompatible with one another when brought together in the genome of a hybrid. It can be difficult for such incompatibilities to originate when populations diverge with gene flow, because deleterious genotypic combinations will be created and then purged by selection. However, it has been argued that if genes underlying incompatibilities are themselves subject to divergent selection, then they might overcome gene flow to diverge between populations, resulting in the origin of incompatibilities. Nonetheless, there has been little explicit mathematical exploration of such scenarios for the origin of intrinsic incompatibilities during ecological speciation with gene flow. Here we explore theoretical models for the origin of intrinsic isolation where genes subject to divergent natural selection also affect intrinsic isolation, either directly or via linkage disequilibrium with other loci. Such genes indeed overcome gene flow, diverge between populations, and thus result in the evolution of intrinsic isolation. We also examine barriers to neutral gene flow. Surprisingly, we find that intrinsic isolation sometimes weakens this barrier, by impeding differentiation via ecologically based divergent selection.

Evidence for divergent natural selection of a Lake Tanganyika cichlid inferred from repeated radiations in body size

2009 ◽  
Vol 18 (14) ◽  
pp. 3110-3119 ◽  
Author(s):  
T. TAKAHASHI ◽  
K. WATANABE ◽  
H. MUNEHARA ◽  
L. RÜBER ◽  
M. HORI
Keyword(s):  
Body Size ◽  
Natural Selection ◽  
Lake Tanganyika ◽  
Divergent Natural Selection ◽  
Selection Of

scholarly journals Intraspecific adaptive radiation: Competition, ecological opportunity, and phenotypic diversification within species

Evolution ◽  
2017 ◽  
Vol 71 (10) ◽  
pp. 2496-2509 ◽  
Author(s):  
Nicholas A. Levis ◽  
Ryan A. Martin ◽  
Kerry A. O'Donnell ◽  
David W. Pfennig
Keyword(s):  
Adaptive Radiation ◽  
Ecological Opportunity ◽  
Phenotypic Diversification

scholarly journals Biased movement drives local cryptic coloration on distinct urban pavements

2019 ◽  
Vol 286 (1912) ◽  
pp. 20191343 ◽  
Author(s):  
Pim Edelaar ◽  
Adrian Baños-Villalba ◽  
David P. Quevedo ◽  
Graciela Escudero ◽  
Daniel I. Bolnick ◽  
...  
Keyword(s):  
Natural Selection ◽  
Habitat Choice ◽  
Mortality Rates ◽  
Urban Environments ◽  
Adaptive Plasticity ◽  
Relative Importance ◽  
Divergent Natural Selection ◽  
Cryptic Coloration ◽  
Selective Agents ◽  
General Studies

Explanations of how organisms might adapt to urban environments have mostly focused on divergent natural selection and adaptive plasticity. However, differential habitat choice has been suggested as an alternative. Here, we test for habitat choice in enhancing crypsis in ground-perching grasshoppers colonizing an urbanized environment, composed of a mosaic of four distinctly coloured substrates (asphalt roads and adjacent pavements). Additionally, we determine its relative importance compared to present-day natural selection and phenotypic plasticity. We found that grasshoppers are very mobile, but nevertheless approximately match the colour of their local substrate. By manipulating grasshopper colour, we confirm that grasshoppers increase the usage of those urban substrates that resemble their own colours. This selective movement actively improves crypsis. Colour divergence between grasshoppers on different substrates is not or hardly owing to present-day natural selection, because observed mortality rates are too low to counteract random substrate use. Additional experiments also show negligible contributions from plasticity in colour. Our results confirm that matching habitat choice can be an important driver of adaptation to urban environments. In general, studies should more fully incorporate that individuals are not only selective targets (i.e. selected on by the environment), but also selective agents (i.e. selecting their own environments).

scholarly journals Assortative flocking in crossbills and implications for ecological speciation

2012 ◽  
Vol 279 (1745) ◽  
pp. 4223-4229 ◽  
Author(s):  
Julie W. Smith ◽  
Stephanie M. Sjoberg ◽  
Matthew C. Mueller ◽  
Craig W. Benkman
Keyword(s):  
Natural Selection ◽  
Reproductive Isolation ◽  
Assortative Mating ◽  
Ecological Speciation ◽  
Central Question ◽  
Loxia Curvirostra ◽  
Call Type ◽  
Divergent Natural Selection ◽  
Contact Calls ◽  
Red Crossbills

How reproductive isolation is related to divergent natural selection is a central question in speciation. Here, we focus on several ecologically specialized taxa or ‘call types’ of red crossbills ( Loxia curvirostra complex), one of the few groups of birds providing much evidence for ecological speciation. Call types differ in bill sizes and feeding capabilities, and also differ in vocalizations, such that contact calls provide information on crossbill phenotype. We found that two call types of red crossbills were more likely to approach playbacks of their own call type than those of heterotypics, and that their propensity to approach heterotypics decreased with increasing divergence in bill size. Although call similarity also decreased with increasing divergence in bill size, comparisons of responses to familiar versus unfamiliar call types indicate that the decrease in the propensity to approach heterotypics with increasing divergence in bill size was a learned response, and not a by-product of calls diverging pleiotropically as bill size diverged. Because crossbills choose mates while in flocks, assortative flocking could lead indirectly to assortative mating as a by-product. These patterns of association therefore provide a mechanism by which increasing divergent selection can lead to increasing reproductive isolation.

scholarly journals Untangling the Mathematical Relation Between Natural Selection and Adaptive Radiation Using Macromolecules and Microevolutionary Forces

2020 ◽  
pp. 313-339
Author(s):  
Bharat Kwatra ◽  
Maanvi Mudgil
Keyword(s):  
Natural Selection ◽  
Dna Fingerprinting ◽  
Adaptive Radiation ◽  
Environment Interaction ◽  
Male And Female ◽  
Evolutionary Forces ◽  
Gene Environment Interaction ◽  
Gene Environment ◽  
Mathematical Relation

Simulating natural selection over subsequent generations of Oniscus asellus, the fittest selected male and female bugs in different diet was used to analyze the concentration of proteins in their body along their frequency in continuous mapped generations over hundred seed values, further DNA Fingerprinting of these selected bugs revealed a relationship with their parents originated from different geographic areas/borders. It was observed that variation in microevolutionary forces caused variation in macromolecules by setting up a gene-environment interaction which deduced natural selection in order to define adaptive radiation and speciation by micro-evolutionary forces.

scholarly journals Rapid experimental evolution of reproductive isolation from a single natural population

2019 ◽  
Vol 116 (27) ◽  
pp. 13440-13445 ◽  
Author(s):  
Scott M. Villa ◽  
Juan C. Altuna ◽  
James S. Ruff ◽  
Andrew B. Beach ◽  
Lane I. Mulvey ◽  
...  
Keyword(s):  
Body Size ◽  
Natural Selection ◽  
Reproductive Isolation ◽  
Natural Population ◽  
Experimental Evolution ◽  
Natural Populations ◽  
Ecological Speciation ◽  
Phenotypic Trait ◽  
Divergent Natural Selection ◽  
Feather Lice

Ecological speciation occurs when local adaptation generates reproductive isolation as a by-product of natural selection. Although ecological speciation is a fundamental source of diversification, the mechanistic link between natural selection and reproductive isolation remains poorly understood, especially in natural populations. Here, we show that experimental evolution of parasite body size over 4 y (approximately 60 generations) leads to reproductive isolation in natural populations of feather lice on birds. When lice are transferred to pigeons of different sizes, they rapidly evolve differences in body size that are correlated with host size. These differences in size trigger mechanical mating isolation between lice that are locally adapted to the different sized hosts. Size differences among lice also influence the outcome of competition between males for access to females. Thus, body size directly mediates reproductive isolation through its influence on both intersexual compatibility and intrasexual competition. Our results confirm that divergent natural selection acting on a single phenotypic trait can cause reproductive isolation to emerge from a single natural population in real time.

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