GENETIC VARIATION IN A HOST-PARASITE ASSOCIATION: POTENTIAL FOR COEVOLUTION AND FREQUENCY-DEPENDENT SELECTION

Evolution ◽  
2001 ◽  
Vol 55 (6) ◽  
pp. 1136 ◽  
Author(s):  
Hans Joachim Carius ◽  
Tom J. Little ◽  
Dieter Ebert
Keyword(s):  
Genetic Variation ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Host Parasite

scholarly journals Causation without correlation: parasite-mediated frequency-dependent selection and infection prevalence

2021 ◽  
Author(s):  
Curtis M Lively ◽  
Julie Xu ◽  
Frida Ben-Ami
Keyword(s):  
Genetic Diversity ◽  
Natural Populations ◽  
Infection Prevalence ◽  
Strong Positive Correlation ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Host Diversity ◽  
Host Genetic ◽  
Host Parasite

Parasite-mediated selection is thought to maintain host genetic diversity for resistance. We might thus expect to find a strong positive correlation between host genetic diversity and infection prevalence across natural populations. Here we used computer simulations to examine host-parasite coevolution in 20 simi-isolated clonal populations across a broad range of values for both parasite virulence and parasite fecundity. We found that the correlation between host genetic diversity and infection prevalence can be significantly positive for intermediate values of parasite virulence and fecundity. But the correlation can also be weak and statistically non-significant, even when parasite-mediated frequency-dependent selection is the sole force maintaining host diversity. Hence correlational analyses of field populations, while useful, might underestimate the role of parasites in maintaining host diversity.

scholarly journals Negative frequency dependent selection contributes to the maintenance of a global polymorphism in mitochondrial DNA

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Zorana Kurbalija Novičić ◽  
Ahmed Sayadi ◽  
Mihailo Jelić ◽  
Göran Arnqvist
Keyword(s):  
Mitochondrial Dna ◽  
Genetic Variation ◽  
Life History ◽  
Balancing Selection ◽  
Food Resource ◽  
Ecological Processes ◽  
Central Process ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Negative Frequency Dependent Selection

Abstract Background Understanding the forces that maintain diversity across a range of scales is at the very heart of biology. Frequency-dependent processes are generally recognized as the most central process for the maintenance of ecological diversity. The same is, however, not generally true for genetic diversity. Negative frequency dependent selection, where rare genotypes have an advantage, is often regarded as a relatively weak force in maintaining genetic variation in life history traits because recombination disassociates alleles across many genes. Yet, many regions of the genome show low rates of recombination and genetic variation in such regions (i.e., supergenes) may in theory be upheld by frequency dependent selection. Results We studied what is essentially a ubiquitous life history supergene (i.e., mitochondrial DNA) in the fruit fly Drosophila subobscura, showing sympatric polymorphism with two main mtDNA genotypes co-occurring in populations world-wide. Using an experimental evolution approach involving manipulations of genotype starting frequencies, we show that negative frequency dependent selection indeed acts to maintain genetic variation in this region. Moreover, the strength of selection was affected by food resource conditions. Conclusions Our work provides novel experimental support for the view that balancing selection through negative frequency dependency acts to maintain genetic variation in life history genes. We suggest that the emergence of negative frequency dependent selection on mtDNA is symptomatic of the fundamental link between ecological processes related to resource use and the maintenance of genetic variation.

scholarly journals Consistent female preference for rare and unfamiliar male color patterns in wild guppy populations

2019 ◽  
Vol 30 (6) ◽  
pp. 1672-1681 ◽  
Author(s):  
Jennifer J Valvo ◽  
F Helen Rodd ◽  
Kimberly A Hughes
Keyword(s):  
Genetic Variation ◽  
Poecilia Reticulata ◽  
Natural Populations ◽  
Female Preference ◽  
Male Mating ◽  
Color Patterns ◽  
High Genetic Diversity ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Negative Frequency Dependent Selection

Abstract How genetic variation is maintained in ecologically important traits is a central question in evolutionary biology. Male Trinidadian guppies, Poecilia reticulata, exhibit high genetic diversity in color patterns within populations, and field and laboratory studies implicate negative frequency-dependent selection in maintaining this variation. However, behavioral and ecological processes that mediate this selection in natural populations are poorly understood. We evaluated female mate preference in 11 natural guppy populations, including paired populations from high- and low-predation habitats, to determine if this behavior is responsible for negative frequency-dependent selection and to evaluate its prevalence in nature. Females directed significantly more attention to males with rare and unfamiliar color patterns than to males with common patterns. Female attention also increased with the area of male orange coloration, but this preference was independent of the preference for rare and unfamiliar patterns. We also found an overall effect of predation regime; females from high-predation populations directed more attention toward males than those from low-predation populations. Again, however, the habitat-linked preference was statistically independent from the preference for rare and unfamiliar patterns. Because previous research indicates that female attention to males predicts male mating success, we conclude that the prevalence of female preference for males with rare and unfamiliar color patterns across many natural populations supports the hypothesis that female preference is an important process underlying the maintenance of high genetic variation in guppy color patterns.

The evolution of genetic diversity

1979 ◽  
Vol 205 (1161) ◽  
pp. 453-474 ◽  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Enzyme Kinetics ◽  
Genetic Control ◽  
Molecular Level ◽  
Natural Populations ◽  
Morphological Characters ◽  
Continuous Variation ◽  
Frequency Dependent ◽  
Frequency Dependent Selection

The existence within natural populations of large amounts of genetic variation in molecules and morphology presents an evolutionary problem. The ‘neutralist’ solution to this problem, that the variation is usually unimportant to the organisms displaying it, has now lost much of its strength. Interpretations that assume widespread heterozygous advantage also face serious difficulties. A resolution is possible in terms of frequency-dependent selection by predators, parasites and competitors. The evidence for pervasive frequency-dependent selection is now very strong. It appears to follow naturally from the behaviour of predators, from the evolutionary lability of parasites, from the ecology of competition and, at the molecular level, from the phenomena of enzyme kinetics. Such selection can explain the maintenance not only of conventional polymorphism but also of continuous variation in both molecular and morphological characters. It can account for the occurrence of diversity within groups of haploid and self-fertilizing organisms, and for the evolution of differences between individuals in their systems of genetic control.

scholarly journals Coevolution does not slow the rate of loss of heterozygosity in a stochastic host-parasite model with constant population size

2020 ◽  
Author(s):  
Ailene MacPherson ◽  
Matthew J. Keeling ◽  
Sarah P. Otto
Keyword(s):  
Genetic Variation ◽  
Natural Selection ◽  
Population Size ◽  
Finite Population ◽  
Extensive Literature ◽  
Stochastic Perturbations ◽  
Frequency Dependent Selection ◽  
Infinite Population ◽  
Negative Frequency Dependent Selection ◽  
Host Parasite

AbstractCoevolutionary negative frequency dependent selection has been hypothesized to maintain genetic variation in host and parasites. Despite the extensive literature pertaining to host-parasite coevolution, the effect of matching-alleles (MAM) coevolution on the maintenance of genetic variation has not been explicitly modelled in a finite population. The dynamics of the MAM in an infinite population, in fact, suggests that genetic variation in these coevolving populations behaves neutrally. We find that while this is largely true in finite populations two additional phenomena arise. The first of these effects is that of coevolutionary natural selection on stochastic perturbations in host and pathogen allele frequencies. While this may increase or decrease genetic variation, depending on the parameter conditions, the net effect is small relative to that of the second phenomena. Following fixation in the pathogen, the MAM becomes one of directional selection, which in turn rapidly erodes genetic variation in the host. Hence, rather than maintain it, we find that, on average, matching-alleles coevolution depletes genetic variation.

scholarly journals Preserving genes: a model of the maintenance of genetic variation in a metapopulation under frequency-dependent selection

1995 ◽  
Vol 65 (3) ◽  
pp. 175-191 ◽  
Author(s):  
Olivia P. Judson
Keyword(s):  
Genetic Variation ◽  
Natural Populations ◽  
Practical Interest ◽  
Strong Interactions ◽  
Population Subdivision ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Maintenance Of Sex ◽  
Negative Frequency Dependent Selection ◽  
Asexual Populations

SummaryUnderstanding how genetic variability is maintained in natural populations is of both theoretical and practical interest. In particular, the subdivision of populations into demes linked by low levels of migration has been suggested to play an important role. But the maintenance of genetic variation in populations is also often linked to the maintenance of sexual reproduction: any force that acts to maintain sex should also act to maintain variation. One theory for the maintenance of sex, the Red Queen, states that sex and variation are maintained by antagonistic coevolutionary interactions – especially those between hosts and their harmful parasites – that give rise to negative frequency-dependent selection. In this paper I present a model to examine the relationships between population subdivision, negative frequency-dependent selection due to parasites, the maintenance of sex, and the preservation of alleles from fixation. The results show strong interactions between migration rates, negative frequency-dependent selection, and the maintenance of variability for sexual and asexual populations.

scholarly journals MAINTENANCE OF GENETIC VARIATION WITH A FREQUENCY-DEPENDENT SELECTION MODEL AS COMPARED TO THE OVERDOMINANT MODEL

Genetics ◽  
1972 ◽  
Vol 72 (4) ◽  
pp. 771-775 ◽  
Author(s):  
Philip W Hedrick
Keyword(s):  
Genetic Variation ◽  
Finite Population ◽  
Selection Model ◽  
Frequency Change ◽  
Fourth Moment ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Infinite Population ◽  
Dependent Model ◽  
Frequency Dependent Model

ABSTRACT A frequency-dependent selection model proposed by Huang, Singh and Kojima (1971) was found to be more effective at maintaining genetic variation in a finite population than the overdominant model. The fourth moment parameter of the distribution of unfixed states showed that there was a more platykurtic distribution for the frequency-dependent model. This agreed well with the expected gene frequency change found for an infinite population.

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