The ecological causes and consequences of hard and soft selection

2021 ◽  
Author(s):  
Donovan A. Bell ◽  
Ryan P. Kovach ◽  
Zachary L. Robinson ◽  
Andrew R. Whiteley ◽  
Thomas E. Reed
Keyword(s):  
Evolution ◽  
1975 ◽  
Vol 29 (3) ◽  
pp. 465 ◽  
Author(s):  
Bruce Wallace
Keyword(s):  

Genetics ◽  
2002 ◽  
Vol 160 (3) ◽  
pp. 1191-1202 ◽  
Author(s):  
Michael C Whitlock

Abstract The subdivision of a species into local populations causes its response to selection to change, even if selection is uniform across space. Population structure increases the frequency of homozygotes and therefore makes selection on homozygous effects more effective. However, population subdivision can increase the probability of competition among relatives, which may reduce the efficacy of selection. As a result, the response to selection can be either increased or decreased in a subdivided population relative to an undivided one, depending on the dominance coefficient FST and whether selection is hard or soft. Realistic levels of population structure tend to reduce the mean frequency of deleterious alleles. The mutation load tends to be decreased in a subdivided population for recessive alleles, as does the expected inbreeding depression. The magnitude of the effects of population subdivision tends to be greatest in species with hard selection rather than soft selection. Population structure can play an important role in determining the mean fitness of populations at equilibrium between mutation and selection.


Evolution ◽  
2015 ◽  
Vol 69 (6) ◽  
pp. 1361-1374 ◽  
Author(s):  
Arthur E. Weis ◽  
Kyle M. Turner ◽  
Bergita Petro ◽  
Emily J. Austen ◽  
Susana M. Wadgymar

PLoS Genetics ◽  
2014 ◽  
Vol 10 (2) ◽  
pp. e1004179 ◽  
Author(s):  
Igor M. Rouzine ◽  
John M. Coffin ◽  
Leor S. Weinberger

2020 ◽  
Vol 287 (1934) ◽  
pp. 20201111
Author(s):  
Patrick Chen ◽  
Rees Kassen

How genetic variation arises and persists over evolutionary time despite the depleting effects of natural selection remains a long-standing question. Here, we investigate the impacts of two extreme forms of population regulation—at the level of the total, mixed population (hard selection) and at the level of local, spatially distinct patches (soft selection)—on the emergence and fate of diversity under strong divergent selection. We find that while the form of population regulation has little effect on rates of diversification, it can modulate the long-term fate of genetic variation, diversity being more readily maintained under soft selection compared to hard selection. The mechanism responsible for coexistence is negative frequency-dependent selection which, while present initially under both forms of population regulation, persists over the long-term only under soft selection. Importantly, coexistence is robust to continued evolution of niche specialist types under soft selection but not hard selection. These results suggest that soft selection could be a general mechanism for the maintenance of ecological diversity over evolutionary time scales.


Genetics ◽  
2009 ◽  
Vol 182 (4) ◽  
pp. 1387-1389 ◽  
Author(s):  
Jacob A. Moorad ◽  
David W. Hall

2000 ◽  
Vol 75 (3) ◽  
pp. 261-275 ◽  
Author(s):  
Lin Chao ◽  
Kathryn A. Hanley ◽  
Christina L. Burch ◽  
Cecilia Dahlberg ◽  
Paul E. Turner

2013 ◽  
Vol 789 ◽  
pp. 379-382 ◽  
Author(s):  
Corinthias P.M. Sianipar ◽  
Husein Taufiq ◽  
Heny R. Estiningtyas ◽  
Kiyoshi Dowaki ◽  
Akbar Adhiutama ◽  
...  

Appropriate technology is widely recognized as a good solution in providing alternative technology for underdeveloped people who live in a very limited circumstance. However, it is often seen as an idea without clear explanation from engineering perspective. One of critical process in appropriate technology design process is materials selection. This study aims to provide applied logic for selecting materials in the design process. The logic is constructed by surveying previous notions from researchers. Reasoning techniques are explored by using design thinking. This study reveals that there are four focuses which must be applied to find sufficient materials for an appropriate technology. This study also concludes that, unlike pure engineering efforts which tend to substitute materials given in a technology design with locally available ones, appropriate technology start from existing resources to produce its design. It requires soft selection by involving local people in exploring any potential materials which already available in their own area. By looking at previous studies which tended to ignore the contribution from local people in exploring potential materials, this study embraces their involvement and then emcourages insights for further research around it.


2017 ◽  
Author(s):  
Markus Pfenninger

There is increasing evidence that rapid phenotypic adaptation of quantitative traits is not uncommon in nature. However, the circumstances under which rapid adaptation of polygenic traits occurs are not yet understood. Building on previous concepts of soft selection, i.e. frequency and density dependent selection, I developed and tested the hypothesis that adaptation speed of a polygenic trait depends on the number of offspring per breeding pair in a randomly mating diploid population. Using individual based modelling on a range of offspring per parent (2-200) in populations of various size (100-10000 individuals), I could show that the by far largest proportion of variance (42%) was explained by the offspring number, regardless of genetic trait architecture (10-50 loci, different locus contribution distributions). In addition, it was possible to identify the majority of the responsible loci and account for even more of the observed phenotypic change with a moderate population size. The simulation results suggest that offspring numbers may a crucial factor for the adaptation speed of quantitative loci. Moreover, as large offspring numbers translates to a large phenotypic variance in the offspring of each parental pair, this genetic bet hedging strategy increases the chance to contribute to the next generation in unpredictable environments.


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