scholarly journals Evolution of sex ratio through gene loss

2019 ◽  
Vol 116 (26) ◽  
pp. 12919-12924 ◽  
Author(s):  
Da Yin ◽  
Eric S. Haag
Keyword(s):  
Sex Ratio ◽  
Population Growth ◽  
Mating System ◽  
Mating Success ◽  
Population Subdivision ◽  
Male Mating ◽  
Mixed Mating ◽  
Male Mating Success ◽  
Caenorhabditis Briggsae ◽  
Male Frequency

The maintenance of males at intermediate frequencies is an important evolutionary problem. Several species ofCaenorhabditisnematodes have evolved a mating system in which selfing hermaphrodites and males coexist. While selfing produces XX hermaphrodites, cross-fertilization produces 50% XO male progeny. Thus, male mating success dictates the sex ratio. Here, we focus on the contribution of themale secreted short(mss) gene family to male mating success, sex ratio, and population growth. Themssfamily is essential for sperm competitiveness in gonochoristic species, but has been lost in parallel in androdioecious species. Using a transgene to restoremssfunction to the androdioeciousCaenorhabditis briggsae,we examined how mating system and population subdivision influence the fitness of themss+genotype. Consistent with theoretical expectations, whenmss+andmss-null (i.e., wild type) genotypes compete,mss+is positively selected in both mixed-mating and strictly outcrossing situations, though more strongly in the latter. Thus, while sexual mode alone affects the fitness ofmss+, it is insufficient to explain its parallel loss. However, in genetically homogenous androdioecious populations,mss+both increases male frequency and depresses population growth. We propose that the lack of inbreeding depression and the strong subdivision that characterize naturalCaenorhabditispopulations impose selection on sex ratio that makes loss ofmssadaptive after self-fertility evolves.

Some Determinants of the Mating System in a Population of Painted Reed Frogs (Hyperolius Marmoratus)

Behaviour ◽  
1988 ◽  
Vol 106 (3-4) ◽  
pp. 265-278 ◽  
Author(s):  
Steven R. Telford ◽  
Miranda L. Dyson
Keyword(s):  
Mating System ◽  
Mating Success ◽  
Breeding Site ◽  
Mating Strategies ◽  
Operational Sex Ratio ◽  
Advertisement Call ◽  
Male Mating ◽  
Male Mating Success ◽  
Male Population ◽  
Sonic Environment

AbstractHyperolius marmoratus shares its breeding site with 12 synchronously breeding species. Males call from elevated perches to attract females. Observations of captive populations suggest that males may adopt alternative mating strategies when chorus densities are high. Similar strategies were not observed in natural choruses. The operational sex ratio (OSR) was always male-biased and also highly variable. Mating was polygynous, only 25% of the male population actually mated. Females mated either once or twice. Variance in mating success was much greater among males, an obvious consequence of a skewed OSR. Female choice was probably not a causal factor because male mating success was correlated with neither size nor age. Size-based variation in the male advertisement call does exist, but females cannot exploit this potential vocal cue because of their impaired discriminatory ability in a complex sonic environment and the potential risk of mismating. Although the mating system may best be described as lek-like, with males forming organised choruses through competitive interactions, the variance in male mating success is probably a consequence of stochastic factors.

Biased sex ratio and low population density increase male mating success in the bug Nysius huttoni (Heteroptera: Lygaeidae)

2008 ◽  
Vol 96 (1) ◽  
pp. 87-91 ◽  
Author(s):  
Qiao Wang ◽  
Xiong Zhao He ◽  
Linghuan Yang ◽  
Duncan Hedderley ◽  
Lorraine K. Davis
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Mating Success ◽  
Density Increase ◽  
Male Mating ◽  
Male Mating Success ◽  
Biased Sex Ratio

scholarly journals Experimental evolution under varying sex ratio and nutrient availability modulates male mating success in Drosophila melanogaster

2021 ◽  
Author(s):  
Irem Sepil ◽  
Jennifer C. Perry ◽  
Alice Dore ◽  
Tracey Chapman ◽  
Stuart Wigby
Keyword(s):  
Drosophila Melanogaster ◽  
Sex Ratio ◽  
Nutrient Availability ◽  
Mating Success ◽  
Experimental Evolution ◽  
Sex Ratios ◽  
Male Mating ◽  
Male Mating Success ◽  
Restricted Diet ◽  
Protein Restricted Diet

AbstractBiased population sex ratios can alter optimal male mating strategies, and allocation to reproductive traits depends on nutrient availability. However, there is little information on how nutrition interacts with sex ratio to influence the evolution of pre-copulatory and post-copulatory traits separately. To address this omission, here we test how male mating success and reproductive investment evolve under varying sex ratios and adult diet in Drosophila melanogaster using an experimental evolution approach. We found that sex ratio and nutrient availability interacted to determine male pre-copulatory performance. Males from female-biased populations were slow to mate when they evolved on a protein-restricted diet. On the other hand, we found direct and non-interacting effects of sex ratio and nutrient availability on post-copulatory success, without interactions between them. Males that evolved on a protein-restricted diet were poor at suppressing female remating. Males that evolved under equal sex ratios fathered more offspring and were better at supressing female remating, relative to males from male-biased or female-biased populations. These results support the idea that sex ratios and nutrition interact to determine the evolution of pre-copulatory mating traits, but independently influence the evolution of post-copulatory traits.

scholarly journals Mate choice confers direct benefits to females ofAnastrepha fraterculus(Diptera: Tephritidae)

2019 ◽  
Author(s):  
Guillermo E. Bachmann ◽  
Francisco Devescovi ◽  
Ana L. Nussenbaum ◽  
Fabián H. Milla ◽  
Todd E. Shelly ◽  
...  
Keyword(s):  
Mate Choice ◽  
Mating System ◽  
Female Choice ◽  
Mating Success ◽  
Female Preference ◽  
Male Mating ◽  
Male Mating Success ◽  
Lek Mating ◽  
Direct Benefits ◽  
Tephritid Fruit Flies

AbstractExposure to plant compounds and analogues of juvenile hormone (JH) increase male mating success in several species of tephritid fruit flies. Most of these species exhibit a lek mating system, characterized by active female choice. Although the pattern of enhanced male mating success is evident, few studies have investigated what benefits, if any, females gain via choice of exposed males in the lek mating system. In the South American fruit fly,Anastrepha fraterculus, females mate preferentially with males that were exposed to volatiles released by guava fruit or treated with methoprene (a JH analogue). Here, we tested the hypothesis that female choice confers direct fitness benefits in terms of fecundity and fertility. We first carried out mate choice experiments presenting females with males treated and non-treated with guava volatiles or, alternatively, treated and non-treated with methoprene. After we confirm female preference for treated males, we compared the fecundity and fertility between females mated with treated males and non-treated ones. We found thatA. fraterculusfemales that mated with males exposed to guava volatiles showed higher fecundity than females mated to non-exposed males. On the other hand, females that mated methoprene-treated males showed no evidence of direct benefits. Our findings represent the first evidence of a direct benefit associated to female preference for males that were exposed to host fruit odors in tephritid fruit flies. Differences between the two treatments are discussed in evolutionary and pest management terms.

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