Extraordinary Flux in Sex Ratio

Underdominance refers to natural selection against individuals with a heterozygous genotype. Here, we analyse a single-locus underdominant system of two large local populations that exchange individuals at a certain migration rate. The system can be characterized by fixed points in the joint allele frequency space. We address the conditions under which underdominance can be applied to transform a local population that is receiving wildtype immigrants from another population. In a single population, underdominance has the benefit of complete removal of genetically modified alleles (reversibility) and coexistence is not stable. The two population system that exchanges migrants can result in internal stable states, where coexistence is maintained, but with additional release of wildtype individuals the system can be reversed to a fully wildtype state. This property is critically controlled by the migration rate. We approximate the critical minimum frequency required to result in a stable population transformation. We also concentrate on the destabilizing effects of fitness and migration rate asymmetry. Practical implications of our results are discussed in the context of utilizing underdominance to genetically modify wild populations. This is of importance especially for genetic pest management strategies, where locally stable and potentially reversible transformations of populations of disease vector species are of interest.

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“…Soans et al (1974);McInnis et al (1996);Charlat et al (2007)). Because of this we are hesitant to make predictions beyond 10 4 generations.…”

Section: Appendix D Fluctuationsmentioning

confidence: 99%

Using underdominance to bi-stably transform local populations

Altrock

Traulsen

Reeves

et al. 2010

Journal of Theoretical Biology

106

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“…In addition, in both systems, nucleo-cytoplasmic conflicts select for nuclear resistance alleles to counteract the symbiont effect, and resistance has indeed been demonstrated both for feminization [78,79] and male-killing [80]. In the latter case, invasion of a resistant allele has been monitored in the butterfly Hypolimnas bolina and shown to be extremely rapid [81]. As these resistance alleles invade, selective sweeps on linked genes might lead to an important loss of genetic variability in the host species.…”

Section: Effects Of Reproductive Manipulators On Populations and Commmentioning

confidence: 99%

Bacterial symbionts in insects or the story of communities affecting communities

Ferrari

Vavre

2011

Phil. Trans. R. Soc. B

304

280

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Bacterial symbionts are widespread in insects and other animals. Most of them are predominantly vertically transmitted, along with their hosts' genes, and thus extend the heritable genetic variation present in one species. These passengers have a variety of repercussions on the host's phenotypes: besides the cost imposed on the host for maintaining the symbiont population, they can provide fitness advantages to the host or manipulate the host's reproduction. We argue that insect symbioses are ideal model systems for community genetics. First, bacterial symbionts directly or indirectly affect the interactions with other species within a community. Examples include their involvement in modifying the use of host plants by phytophagous insects, in providing resistance to natural enemies, but also in reducing the global genetic diversity or gene flow between populations within some species. Second, one emerging picture in insect symbioses is that many species are simultaneously infected with more than one symbiont, which permits studying the factors that shape bacterial communities; for example, horizontal transmission, interactions between host genotype, symbiont genotype and the environment and interactions among symbionts. One conclusion is that insects' symbiotic complements are dynamic communities that affect and are affected by the communities in which they are embedded.

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“…In such cases, an intermediate rather than maximal signaling effort can still be selected for, if high signaling effort is costly. Such costs can be difficult to detect precisely because females are not typically expected to evolve highly costly mate acquisition traits (Kokko and Wong 2007), but it is noteworthy that (1) costs can shape mating systems even if they are small or (2) sometimes sperm limitation can make females evolve costly mate acquisition traits (for insect data, see Charlat et al 2007;Calabrese et al 2008;Rhainds 2010; for data from spatially varying situations, see Contarini et al 2009;Rhainds 2012). Accordingly, we now assume that multiple male arrivals are not costly (we modify the above model to have k ≥ 1) and include direct costs of pheromone production.…”

Section: Balancing Mate Arrival Rate With Increasing Costs Of Callingmentioning

confidence: 99%

The Mothematics of Female Pheromone Signaling: Strategies for Aging Virgins

Umbers¹,

Symonds

Kokko

2015

The American Naturalist

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Although females rarely experience strong mate limitation, delays or lifelong problems of mate acquisition are detrimental to female fitness. In systems where males search for females via pheromone plumes, it is often difficult to assess whether female signaling is costly. Direct costs include the energetics of pheromone production and attention from unwanted eavesdroppers, such as parasites, parasitoids, and predators. Suboptimal outcomes are also possible from too many or too few mating events or near-simultaneous arrival of males who make unwanted mating attempts (even if successfully thwarted). We show that, in theory, even small costs can lead to a scenario where young females signal less intensely (lower pheromone concentration and/or shorter time spent signaling) and increase signaling effort only as they age and gather evidence (while still virgin) on whether sperm limitation threatens their reproductive success. Our synthesis of the empirical data available on Lepidoptera supports this prediction for one frequently reported component of signalingtime spent calling (often reported as the time of onset of calling at night)-but not for another, pheromone titer. This difference is explicable under the plausible but currently untested assumption that signaling earlier than other females each night is a more reliable way of increasing the probability of acquiring at least one mate than producing a more concentrated pheromone plume. Submitted February 24, 2014; Accepted October 3, 2014; Electronically published February 2, 2015 Online enhancement: appendix.abstract: Although females rarely experience strong mate limitation, delays or lifelong problems of mate acquisition are detrimental to female fitness. In systems where males search for females via pheromone plumes, it is often difficult to assess whether female signaling is costly. Direct costs include the energetics of pheromone production and attention from unwanted eavesdroppers, such as parasites, parasitoids, and predators. Suboptimal outcomes are also possible from too many or too few mating events or near-simultaneous arrival of males who make unwanted mating attempts (even if successfully thwarted). We show that, in theory, even small costs can lead to a scenario where young females signal less intensely (lower pheromone concentration and/or shorter time spent signaling) and increase signaling effort only as they age and gather evidence (while still virgin) on whether sperm limitation threatens their reproductive success. Our synthesis of the empirical data available on Lepidoptera supports this prediction for one frequently reported component of signaling-time spent calling (often reported as the time of onset of calling at night)-but not for another, pheromone titer. This difference is explicable under the plausible but currently untested assumption that signaling earlier than other females each night is a more reliable way of increasing the probability of acquiring at least one mate than producing a more concentrated pheromone plume.

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Extraordinary Flux in Sex Ratio

Cited by 152 publications

References 4 publications

Using underdominance to bi-stably transform local populations

Using underdominance to bi-stably transform local populations

Bacterial symbionts in insects or the story of communities affecting communities

The Mothematics of Female Pheromone Signaling: Strategies for Aging Virgins

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