The interacting effects of genetic variation, habitat quality and population size on performance of Succisa pratensis

2003 ◽  
Vol 91 (1) ◽  
pp. 18-26 ◽  
Author(s):  
Philippine Vergeer ◽  
Ramses Rengelink ◽  
Annemieke Copal ◽  
N. Joop Ouborg
Keyword(s):  
Genetic Variation ◽  
Population Size ◽  
Habitat Quality

scholarly journals Surrounding landscape structures, rather than habitat age, drive genetic variation of typical calcareous grassland plant species

2020 ◽  
Vol 35 (12) ◽  
pp. 2881-2893
Author(s):  
Theresa Anna Lehmair ◽  
Ellen Pagel ◽  
Peter Poschlod ◽  
Christoph Reisch
Keyword(s):  
Genetic Diversity ◽  
Land Use ◽  
Genetic Variation ◽  
Population Size ◽  
Habitat Quality ◽  
Landscape Structure ◽  
Calcareous Grassland ◽  
Calcareous Grasslands ◽  
Surrounding Landscape ◽  
Swabian Alb

Abstract Context Land use change reduced calcareous grasslands throughout Europe during the last decades. Subsequent fragmentation and habitat deterioration led, moreover, to a massive biodiversity decline. To counteract this alarming development, a clear understanding of genetic variation patterns, as fundamental level of biodiversity, becomes inevitable. Objectives The aim of our study was to identify the drivers of genetic variation in common calcareous grassland plant species. More specifically, we tested whether genetic diversity or differentiation of Asperula cynanchica, Campanula rotundifolia, and Linum catharticum depend on habitat age, landscape structure, habitat quality, and/or population size. Methods We investigated 912 individuals, 304 per study species, from 19 calcareous grasslands across the Swabian Alb in Baden-Württemberg (Germany) using AFLP analyses. Results We observed no significant influence of habitat age on genetic diversity and differentiation. Habitat quality also had no impact on genetic diversity and population size only showed weak effects. However, genetic diversity strongly depended on landscape structure represented by distance to the nearest settlement, total area of surrounding calcareous grasslands, and their connectivity. Conclusions Migratory sheep herding is considered as main land use in calcareous grasslands on the Swabian Alb and thus, landscape structures in the study region may describe movement patterns of grazing livestock. In this study, genetic variation in calcareous grassland populations was strongly affected by surrounding landscape structures and subsequent grazing patterns. Therefore, we assume that moderate grazing intensities over the long term may increase levels of genetic diversity, whereas periods of overgrazing or abandonment could lower genetic diversity.

scholarly journals Rapid declines in habitat quality and population size of the Liben (Sidamo) Lark Heteromirafra sidamoensis necessitate immediate conservation action – ERRATUM

2010 ◽  
Vol 20 (2) ◽  
pp. 214-214 ◽  
Author(s):  
PAUL F. DONALD ◽  
GRAEME M. BUCHANAN ◽  
NIGEL J. COLLAR ◽  
YILMA DELLELEGN ABEBE ◽  
MERID N. GABREMICHAEL ◽  
...  
Keyword(s):  
Population Size ◽  
Habitat Quality ◽  
Conservation Action

scholarly journals How general are positive relationships between plant population size, fitness and genetic variation?

2006 ◽  
Vol 94 (5) ◽  
pp. 942-952 ◽  
Author(s):  
ROOSA LEIMU ◽  
PIA MUTIKAINEN ◽  
JULIA KORICHEVA ◽  
MARKUS FISCHER
Keyword(s):  
Genetic Variation ◽  
Population Size ◽  
Plant Population ◽  
Positive Relationships ◽  
Plant Population Size

scholarly journals Upland Habitat Quality and Historic Landscape Composition Influence Genetic Variation of a Pond-Breeding Salamander

Diversity ◽  
2013 ◽  
Vol 5 (4) ◽  
pp. 724-733 ◽  
Author(s):  
Stephen Richter ◽  
Steven Price ◽  
Chelsea Kross ◽  
Jeremiah Alexander ◽  
Michael Dorcas
Keyword(s):  
Genetic Variation ◽  
Habitat Quality ◽  
Landscape Composition ◽  
Historic Landscape

scholarly journals The distribution of mutational effects on fitness in Caenorhabditis elegans inferred from standing genetic variation

2020 ◽  
Author(s):  
Kimberly J. Gilbert ◽  
Stefan Zdraljevic ◽  
Daniel E. Cook ◽  
Asher D. Cutter ◽  
Erik C. Andersen ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Caenorhabditis Elegans ◽  
Population Size ◽  
Genomic Structure ◽  
Random Mating ◽  
Population Substructure ◽  
C Elegans ◽  
Fitness Effects ◽  
Self Fertilization ◽  
New Mutations

ABSTRACTThe distribution of fitness effects for new mutations is one of the most theoretically important but difficult to estimate properties in population genetics. A crucial challenge to inferring the distribution of fitness effects (DFE) from natural genetic variation is the sensitivity of the site frequency spectrum to factors like population size change, population substructure, and non-random mating. Although inference methods aim to control for population size changes, the influence of non-random mating remains incompletely understood, despite being a common feature of many species. We report the distribution of fitness effects estimated from 326 genomes of Caenorhabditis elegans, a nematode roundworm with a high rate of self-fertilization. We evaluate the robustness of DFE inferences using simulated data that mimics the genomic structure and reproductive life history of C. elegans. Our observations demonstrate how the combined influence of self-fertilization, genome structure, and natural selection can conspire to compromise estimates of the DFE from extant polymorphisms. These factors together tend to bias inferences towards weakly deleterious mutations, making it challenging to have full confidence in the inferred DFE of new mutations as deduced from standing genetic variation in species like C. elegans. Improved methods for inferring the distribution of fitness effects are needed to appropriately handle strong linked selection and selfing. These results highlight the importance of understanding the combined effects of processes that can bias our interpretations of evolution in natural populations.

scholarly journals Population size, habitat fragmentation, and the nature of adaptive variation in a stream fish

2014 ◽  
Vol 281 (1790) ◽  
pp. 20140370 ◽  
Author(s):  
Dylan J. Fraser ◽  
Paul V. Debes ◽  
Louis Bernatchez ◽  
Jeffrey A. Hutchings
Keyword(s):  
Genetic Variation ◽  
Habitat Fragmentation ◽  
Population Size ◽  
Brook Trout ◽  
Small Populations ◽  
Adaptive Genetic Variation ◽  
Genetic Population ◽  
Fragmented Populations ◽  
Large Populations ◽  
Adaptive Differentiation

Whether and how habitat fragmentation and population size jointly affect adaptive genetic variation and adaptive population differentiation are largely unexplored. Owing to pronounced genetic drift, small, fragmented populations are thought to exhibit reduced adaptive genetic variation relative to large populations. Yet fragmentation is known to increase variability within and among habitats as population size decreases. Such variability might instead favour the maintenance of adaptive polymorphisms and/or generate more variability in adaptive differentiation at smaller population size. We investigated these alternative hypotheses by analysing coding-gene, single-nucleotide polymorphisms associated with different biological functions in fragmented brook trout populations of variable sizes. Putative adaptive differentiation was greater between small and large populations or among small populations than among large populations. These trends were stronger for genetic population size measures than demographic ones and were present despite pronounced drift in small populations. Our results suggest that fragmentation affects natural selection and that the changes elicited in the adaptive genetic composition and differentiation of fragmented populations vary with population size. By generating more variable evolutionary responses, the alteration of selective pressures during habitat fragmentation may affect future population persistence independently of, and perhaps long before, the effects of demographic and genetic stochasticity are manifest.

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