Extensive gene flow along the urban-rural gradient in a migratory colonial bird

2018 ◽  
Vol 49 (6) ◽  
Author(s):  
Piotr Indykiewicz ◽  
Patrycja Podlaszczuk ◽  
Aleksandra Janiszewska ◽  
Piotr Minias
Keyword(s):  
Gene Flow ◽  
Colonial Bird ◽  
Urban Rural

scholarly journals Contrasting the effects of natural selection, genetic drift and gene flow on urban evolution in white clover ( Trifolium repens )

2018 ◽  
Vol 285 (1883) ◽  
pp. 20181019 ◽  
Author(s):  
Marc T. J. Johnson ◽  
Cindy M. Prashad ◽  
Mélanie Lavoignat ◽  
Hargurdeep S. Saini
Keyword(s):  
Gene Flow ◽  
Natural Selection ◽  
Genetic Drift ◽  
White Clover ◽  
Trifolium Repens ◽  
Rural Areas ◽  
Isolation By Distance ◽  
Urban Centre ◽  
Production Of Hydrogen ◽  
Urban Rural

Urbanization is a global phenomenon with profound effects on the ecology and evolution of organisms. We examined the relative roles of natural selection, genetic drift and gene flow in influencing the evolution of white clover ( Trifolium repens ), which thrives in urban and rural areas. Trifolium repens exhibits a Mendelian polymorphism for the production of hydrogen cyanide (HCN), a potent antiherbivore defence. We quantified the relative frequency of HCN in 490 populations sampled along urban–rural transects in 20 cities. We also characterized genetic variation within 120 populations in eight cities using 16 microsatellite loci. HCN frequency increased by 0.6% for every kilometre from an urban centre, and the strength of this relationship did not significantly vary between cities. Populations did not exhibit changes in genetic diversity with increasing urbanization, indicating that genetic drift is unlikely to explain urban–rural clines in HCN frequency. Populations frequently exhibited isolation-by-distance and extensive gene flow along most urban–rural transects, with the exception of a single city that exhibited genetic differentiation between urban and rural populations. Our results show that urbanization repeatedly drives parallel evolution of an ecologically important trait across many cities that vary in size, and this evolution is best explained by urban–rural gradients in natural selection.

scholarly journals Urbanization impacts apex predator gene flow but not genetic diversity across an urban‐rural divide

2019 ◽  
Vol 28 (22) ◽  
pp. 4926-4940 ◽  
Author(s):  
Daryl R. Trumbo ◽  
Patricia E. Salerno ◽  
Kenneth A. Logan ◽  
Mathew W. Alldredge ◽  
Roderick B. Gagne ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Apex Predator ◽  
Urban Rural

scholarly journals Evidence for human-mediated range expansion and gene flow in an invasive grass

2018 ◽  
Vol 285 (1882) ◽  
pp. 20181125 ◽  
Author(s):  
Tina M. Arredondo ◽  
Gina L. Marchini ◽  
Mitchell B. Cruzan
Keyword(s):  
Gene Flow ◽  
Genetic Distance ◽  
Canopy Cover ◽  
Invasive Grass ◽  
Single Nucleotide ◽  
Brachypodium Sylvaticum ◽  
Dispersal Mechanism ◽  
Genome Wide ◽  
Urban Rural ◽  
Landscape Feature

Cities and adjacent regions represent foci of intense human activity and provide unique opportunities for studying human-mediated dispersal and gene flow. We examined the effect of landscape features on gene flow in the invasive grass Brachypodium sylvaticum across an urban–rural interface at the edge of its expanding range. We used genome-wide single-nucleotide polymorphism surveys of individuals from 22 locations. Resistance surfaces were created for each landscape feature, using ResistanceGA to optimize resistance parameters. Our S tructure analysis identified three distinct clusters, and diversity analyses support the existence of at least three local introductions. Multiple regression on distance matrices showed no evidence that development, roads, canopy cover or agriculture had a significant influence on genetic distance in B. sylvaticum . Geographical distance was a mediocre predictor of genetic distance and reflected geographical clustering. The model of rivers acting as a conduit explained a large portion of variation in genetic distance, but the lack of evidence of directional gene flow eliminated hydrochory as a dispersal mechanism. These results and observations of the distribution of populations in disturbed sites indicate that the influence of rivers on patterns of dispersal of B. sylvaticum probably reflects seed dispersal due to human recreational activity.

Great Wall blocks gene flow

Nature ◽  
2003 ◽  
Author(s):  
HelenR. Pilcher
Keyword(s):  
Gene Flow ◽  
Great Wall

Socio-Economic Characteristics of Immigrants in Western Greece Region: Urban – Rural Continuum or Divide?

2006 ◽  
Vol 3 (2) ◽  
pp. 91-105 ◽  
Author(s):  
Theodoros Iosifides ◽  
Thanasis Kizos ◽  
Elektra Petracou ◽  
Ekaterini Malliotaki ◽  
Konstantina Katsimantou ◽  
...  
Keyword(s):  
Rural Areas ◽  
Urban Centers ◽  
Spatial Factors ◽  
Limited Role ◽  
Urban Rural ◽  
Of Greece ◽  
Western Greece

This paper aims at an investigation of factors of differentiation of basic social and economic characteristics of foreign immigrants in the Region of Western Greece. The paper explores whether the thesis of urban-rural divide is relevant for the differentiation of immigrants’ socio-economic characteristics in a typical Region of Greece, where there is a strong interplay between major urban centers and large rural areas. Findings show that spatial factors play a very limited role in the differentiation of socio-economic characteristics of immigrants and indicate that other factors are more important. Thus, and as regards socio-economic characteristics of immigrants, the overall picture is that of urban-rural continuum rather than divide. 

A review on the prerequisites of Evidence-Based Curriculum as a driver to skills development of the leather value chain in Africa

2019 ◽  
Vol 5 (1) ◽  
pp. 1-10
Author(s):  
Mwinyikione Mwinyihija
Keyword(s):  
Higher Education ◽  
Curriculum Design ◽  
Value Chain ◽  
Theoretical Perspective ◽  
Economic Benefits ◽  
Skills Development ◽  
Evidence Based ◽  
Wealth Creation ◽  
Urban Rural ◽  
Review Study

The review study closely introspects’ on the prerequisites of evidence-based curriculum within the realms of specialized skills development agenda as pursued through higher education Institutions in Africa. Explicitly, the constraining factors that bedevil the leather sector are identifiable when appropriate research designs tools are applied. As such, in the process of identifying the constraints, renascence themes could, therefore, be beneficial in collecting evidence in support of developing curriculum. Such a developed curriculum stands higher chances of acceptability and aptly mitigates against challenges related to specialized skills development. The review succinctly indicates that in the process of identifying the themes, the scope of collecting evidence becomes attainable, thus, improving curricula that entails a participatory and transformative orientation. Indeed, during the review phase of the study, three main perspectives are depicted to be consequential in attaining a comprehensive, evidence-based curriculum, such as; action research, backward curriculum design perspective and theoretical perspective. Therefore, about this perspective, a reflection based on personal experiences and related to new knowledge with what they already know leads to constructivism. The relevancy of a constructivist strategy is observed to facilitate the observatory and evaluative stance during the development of evidence-based curriculum. Moreover, in consolidating and sustaining the benefit of such a developed curriculum, threshold concept was found during the review that it complements the process and strengthens the collecting evidence for curriculum development. Accordingly, therefore, the result of the review study indicate that Africa would  position itself for initiating transformational changes in aspects of specialized higher education, fruition towards socio-economic benefits (e.g. employment, wealth creation and technology transfer), reversal of urban-rural or inter/intra continental migration flurry.

A Study of the Urban-Rural Poverty Gap by Applying Definition of Multidimensional Poverty to Korean Welfare Panel Data, 2005-2011

2014 ◽  
Vol 34 (1) ◽  
pp. 5-51 ◽  
Author(s):  
Kim Heyei-ja ◽  
김정은 ◽  
고난난 ◽  
박지영 ◽  
진나연
Keyword(s):  
Panel Data ◽  
Rural Poverty ◽  
Multidimensional Poverty ◽  
Urban Rural ◽  
Definition Of
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