scholarly journals LANDSCAPE GENOMICS OFPOPULUS TRICHOCARPA: THE ROLE OF HYBRIDIZATION, LIMITED GENE FLOW, AND NATURAL SELECTION IN SHAPING PATTERNS OF POPULATION STRUCTURE

Evolution ◽  
2014 ◽  
Vol 68 (11) ◽  
pp. 3260-3280 ◽  
Author(s):  
Armando Geraldes ◽  
Nima Farzaneh ◽  
Christopher J. Grassa ◽  
Athena D. McKown ◽  
Robert D. Guy ◽  
...  
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Natural Selection ◽  
Landscape Genomics ◽  
Limited Gene Flow

Differentiation and Interrelations of Two Representatives of Laudakia stellio Complex (Reptilia: Agamidae) in Israel

2011 ◽  
Vol 4 (2) ◽  
pp. 102-114 ◽  
Author(s):  
Evgenyi N. Panov ◽  
Larissa Yu. Zykova
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Habitat Preference ◽  
Additional Data ◽  
Near East ◽  
Field Studies ◽  
Subspecies Level ◽  
Limited Gene Flow ◽  
Study Sites ◽  
And Behavior

Field studies were conducted in Central Negev within the breeding range of Laudakia stellio brachydactyla and in NE Israel (Qyriat Shemona) in the range of an unnamed form (tentatively “Near-East Rock Agama”), during March – May 1996. Additional data have been collected in Jerusalem at a distance of ca. 110 km from the first and about 170 km from the second study sites. A total of 63 individuals were caught and examined. The animals were marked and their subsequent movements were followed. Social and signal behavior of both forms were described and compared. Lizards from Negev and Qyriat Shemona differ from each other sharply in external morphology, habitat preference, population structure, and behavior. The differences obviously exceed the subspecies level. At the same time, the lizards from Jerusalem tend to be intermediate morphologically between those from both above-named localities, which permits admitting the existence of a limited gene flow between lizard populations of Negev and northern Israel. The lizards from NE Israel apparently do not belong to the nominate subspecies of L. stellio and should be regarded as one more subspecies within the species.

scholarly journals Population structure, gene flow and natural selection in populations of Euphydryas phaeton

Heredity ◽  
1975 ◽  
Vol 34 (3) ◽  
pp. 407-415 ◽  
Author(s):  
Peter F Brussard ◽  
A Thomas Vawter
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Natural Selection

scholarly journals The genomic basis of domestic colonisation and dispersal in Chagas disease vectors

2021 ◽  
Author(s):  
Luis E Hernandez-Castro ◽  
Anita G Villacís ◽  
Arne Jacobs ◽  
Bachar Cheaib ◽  
Casey C Day ◽  
...  
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Local Adaptation ◽  
Chagas Disease ◽  
Regional Scale ◽  
Landscape Genomics ◽  
Human Habitat ◽  
Rhodnius Ecuadoriensis ◽  
Genomic Adaptation ◽  
Domestic Setting

AbstractThe biology of vector adaptation to the human habitat remains poorly understood for many arthropod-borne diseases but underpins effective and sustainable disease control. We adopted a landscape genomics approach to investigate gene flow, signatures of local adaptation, and drivers of population structure among multiple linked wild and domestic population pairs in Rhodnius ecuadoriensis, an important vector of Chagas Disease. Evidence of high triatomine gene flow (FST) between wild and domestic ecotopes at sites throughout the study area indicate insecticide-based control will be hindered by constant re-infestation of houses. Genome scans revealed genetic loci with strong signal of local adaptation to the domestic setting, which we mapped to annotated regions in the Rhodnius prolixus genome. Our landscape genomic mixed effects models showed Rhodnius ecuadoriensis population structure and connectivity is driven by landscape elevation at a regional scale. Our ecologically- and spatially-explicit vector dispersal model enables targeted vector control and recommends spatially discrete, periodic interventions to local authorities as more efficacious than current, haphazard approaches. In tandem, evidence for parallel genomic adaptation to colonisation of the domestic environment at multiple sites sheds new light on the evolutionary basis of adaptation to the human host in arthropod vectors.

Are there populations suffering genetic erosion that would benefit from gene flow?

2019 ◽  
pp. 97-114
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Paradigm Shift ◽  
Genetic Erosion ◽  
Genetic Rescue ◽  
Limited Gene Flow

Evidence of population structure and limited gene flow often leads to the questionable conclusion that populations should be managed as separate unit. A paradigm shift is needed where evidence of genetic differentiation among populations is followed by an assessment of whether populations are suffering genetic erosion, whether there are other populations to which they could be crossed, and whether the crosses would be beneficial, or harmful, and if beneficial, whether the benefits would be large enough to justify a genetic rescue attempt. Here we address these questions based on the principles established in the preceding chapters.

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.

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

2018 ◽  
Vol 285 (1878) ◽  
pp. 20180230 ◽  
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

Urban 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 (hydrogen cyanide, 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.

Population fragmentation causes inadequate gene flow and increases extinction risk

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Gene Flow ◽  
Extinction Risk ◽  
Random Mating ◽  
Large Population ◽  
Isolated Population ◽  
Population Fragmentation ◽  
Single Population ◽  
Total Size ◽  
Limited Gene Flow

Most species now have fragmented distributions, often with adverse genetic consequences. The genetic impacts of population fragmentation depend critically upon gene flow among fragments and their effective sizes. Fragmentation with cessation of gene flow is highly harmful in the long term, leading to greater inbreeding, increased loss of genetic diversity, decreased likelihood of evolutionary adaptation and elevated extinction risk, when compared to a single population of the same total size. The consequences of fragmentation with limited gene flow typically lie between those for a large population with random mating and isolated population fragments with no gene flow.

Randomness and Complexity

2018 ◽  
Author(s):  
Steven E. Vigdor
Keyword(s):  
Quantum Mechanics ◽  
Natural Selection ◽  
Rna World ◽  
Biological Evolution ◽  
Variable Theory ◽  
Cosmological Natural Selection ◽  
Einstein Podolsky Rosen ◽  
World Hypothesis ◽  
Rna World Hypothesis

Chapter 7 describes the fundamental role of randomness in quantum mechanics, in generating the first biomolecules, and in biological evolution. Experiments testing the Einstein–Podolsky–Rosen paradox have demonstrated, via Bell’s inequalities, that no local hidden variable theory can provide a viable alternative to quantum mechanics, with its fundamental randomness built in. Randomness presumably plays an equally important role in the chemical assembly of a wide array of polymer molecules to be sampled for their ability to store genetic information and self-replicate, fueling the sort of abiogenesis assumed in the RNA world hypothesis of life’s beginnings. Evidence for random mutations in biological evolution, microevolution of both bacteria and antibodies and macroevolution of the species, is briefly reviewed. The importance of natural selection in guiding the adaptation of species to changing environments is emphasized. A speculative role of cosmological natural selection for black-hole fecundity in the evolution of universes is discussed.

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