Operational sex ratio and paternal age sway mating and reproductive performance in Menochilus sexmaculatus (Coleoptera: Coccinellidae)

2020 ◽  
Vol 152 (3) ◽  
pp. 298-310
Author(s):  
Swati Saxena ◽  
Geetanjali Mishra ◽  
Omkar
Keyword(s):  
Sex Ratio ◽  
Reproductive Performance ◽  
Mating Behaviour ◽  
Age Groups ◽  
Paternal Age ◽  
Operational Sex Ratio ◽  
Middle Aged ◽  
Developmental Duration ◽  
Development Duration ◽  
Older Males

AbstractOperational sex ratio and paternal age are known to independently affect mating behaviour and reproductive performance. We conducted experiments to assess the effects of operational sex ratio and paternal age on mating, reproduction, and total development duration of Menochilus sexmaculatus (Fabricius) (Coleoptera: Coccinellidae). Three male-biased sex ratios, no (1:1), modest (1:2), and extreme (1:5) competition treatments, were formed using young, middle-aged, and old males. The reproductive performance of M. sexmaculatus at all ages under extreme competition (1:5) surpassed the other two treatments. More competition among males decreased the time of commencement of mating and increased the duration of copulation. Females laid a greater number of eggs in extreme competition treatments. The operational sex ratio (irrespective of age) had no significant effect on the total developmental duration of offspring. Among different age groups, older males took more time to commence mating and mated for longer durations in all the sex ratio treatments. The number of eggs in the first clutch was lowest when females were mated with older males with increased offspring development duration. Thus, it can be concluded that male-biased sex ratio elevates the performance of M. sexmaculatus. Among different age groups, older males were poor performers than young and middle-aged males.

Mating Tactics in the Tropical Millipede Alloporus Uncinatus (Diplopoda: Spirostreptidae)

Behaviour ◽  
1993 ◽  
Vol 124 (1-2) ◽  
pp. 45-56 ◽  
Author(s):  
Steven R. Telford ◽  
J. Mark Dangerfield
Keyword(s):  
Sex Ratio ◽  
Mating System ◽  
Sperm Competition ◽  
Breeding Season ◽  
Female Choice ◽  
Laboratory Experiments ◽  
Mating Behaviour ◽  
Operational Sex Ratio ◽  
Mating Tactics ◽  
Mate Acquisition

AbstractField and laboratory observations of mating behaviour in a population of the tropical millipede Alloporus uncinatus were carried out over one breeding season. Males obtained mates through random encounters and by forming triplet associations with copula pairs. The occurrence of triplet associations in the field was coincident with a highly male biased operational sex ratio. Mate acquisition by males was apparently stochastic and direct physical competition did not occur. In laboratory experiments mating was size-selective probably as a consequence of female choice. We consider the possibility that sperm competition has contributed to the evolution of the mating system in this species.

Do operational sex ratio and density affect mating behaviour? An experiment on the two-spotted goby

2009 ◽  
Vol 78 (5) ◽  
pp. 1229-1238 ◽  
Author(s):  
Karen de Jong ◽  
Sebastian Wacker ◽  
Trond Amundsen ◽  
Elisabet Forsgren
Keyword(s):  
Sex Ratio ◽  
Mating Behaviour ◽  
Operational Sex Ratio

scholarly journals Operational Sex Ratio Predicts Binge Drinking Across U.S. Counties

2019 ◽  
Vol 17 (3) ◽  
pp. 147470491987468 ◽  
Author(s):  
Toe Aung ◽  
Susan M. Hughes ◽  
Liana S. E. Hone ◽  
David A. Puts
Keyword(s):  
Sex Ratio ◽  
Binge Drinking ◽  
Evolutionary Theory ◽  
Age Groups ◽  
Census Bureau ◽  
Operational Sex Ratio ◽  
Mixed Effects Models ◽  
County Level ◽  
The Relationship ◽  
Binge Drinker

Previous research suggests that binge drinking among young men serves as a “costly signal” to potential mates, such that the binge drinker is capable of bearing the harmful consequences of alcohol consumption. Here, we propose that binge drinking among young adults is conditionally dependent upon the signaler’s willingness to take risks, which is influenced by the local operational sex ratio (OSR). Using archived binge drinking estimates from 2009 to 2012 and Census Bureau records of OSRs, we tested the relationship between OSR and binge drinking rates at the county level across 3,143 U.S. counties against hypotheses drawn from evolutionary theory. Results from our mixed-effects models revealed that a higher overall OSR (i.e., more eligible men compared to women) was associated with higher male binge drinking rates but lower female binge drinking rates. A higher OSR particularly in the 20–29 and 50+ age groups predicted higher male binge drinking rates but lower female binge drinking rates. Our findings generally support predictions derived from evolutionary theory and suggest that binge drinking may function as a costly sexual signal, conditionally regulated by age and the local sex ratio.

scholarly journals Adaptations to sexual selection and sexual conflict: insights from experimental evolution and artificial selection

2010 ◽  
Vol 365 (1552) ◽  
pp. 2541-2548 ◽  
Author(s):  
Dominic A. Edward ◽  
Claudia Fricke ◽  
Tracey Chapman
Keyword(s):  
Sexual Selection ◽  
Sex Ratio ◽  
Sexual Conflict ◽  
Artificial Selection ◽  
Experimental Evolution ◽  
Genetic Basis ◽  
Mating Behaviour ◽  
Evolutionary Change ◽  
Operational Sex Ratio ◽  
Adult Sex Ratio

Artificial selection and experimental evolution document natural selection under controlled conditions. Collectively, these techniques are continuing to provide fresh and important insights into the genetic basis of evolutionary change, and are now being employed to investigate mating behaviour. Here, we focus on how selection techniques can reveal the genetic basis of post-mating adaptations to sexual selection and sexual conflict. Alteration of the operational sex ratio of adult Drosophila over just a few tens of generations can lead to altered ejaculate allocation patterns and the evolution of resistance in females to the costly effects of elevated mating rates. We provide new data to show how male responses to the presence of rivals can evolve. For several traits, the way in which males responded to rivals was opposite in lines selected for male-biased, as opposed to female-biased, adult sex ratio. This shows that the manipulation of the relative intensity of intra- and inter-sexual selection can lead to replicable and repeatable effects on mating systems, and reveals the potential for significant contemporary evolutionary change. Such studies, with important safeguards, have potential utility for understanding sexual selection and sexual conflict across many taxa. We discuss how artificial selection studies combined with genomics will continue to deepen our knowledge of the evolutionary principles first laid down by Darwin 150 years ago.

The Effects of Significant International Sports Events on Hungarian Suicide Rates

Crisis ◽  
2016 ◽  
Vol 37 (2) ◽  
pp. 148-154 ◽  
Author(s):  
Karoly Bozsonyi ◽  
Peter Osvath ◽  
Sandor Fekete ◽  
Lajos Bálint
Keyword(s):  
Significant Relationship ◽  
Olympic Games ◽  
Arima Model ◽  
Age Groups ◽  
The Elderly ◽  
Intervention Analysis ◽  
Middle Aged ◽  
Sports Events ◽  
Sport Events ◽  
The Olympic Games

Abstract. Background: Several studies found a significant relationship between important sport events and suicidal behavior. Aims: We set out to investigate whether there is a significant relationship between the raw suicide rate and the most important international sports events (Olympic Games, FIFA World Cup, UEFA European Championship) in such an achievement-oriented society as the Hungarian one, where these sport events receive great attention. Method: We examined suicide cases occurring over 15,706 days between January 1, 1970, and December 31, 2012 (43 years), separately for each gender. Because of the age-specific characteristics of suicide, the effects of these sport events were analyzed for the middle-aged (30–59 years old) and the elderly (over 60 years old) generations as well as for gender-specific population groups. The role of international sport events was examined with the help of time-series intervention analysis after cyclical and seasonal components were removed. Intervention analysis was based on the ARIMA model. Results: Our results showed that only the Olympic Games had a significant effect in the middle-aged population. Neither in the older male nor in any of the female age groups was a relationship between suicide and Olympic Games detected. Conclusion: The Olympic Games seem to decrease the rate of suicide among middle-aged men, slightly but significantly.

Offspring sex ratio in moose Alces alces in relation to paternal age: an experiment

2004 ◽  
Vol 10 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Bernt-Erik Sæther ◽  
Erling J. Solberg ◽  
Morten Heim ◽  
John E. Stacy ◽  
Kjetill S. Jakobsen ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Alces Alces ◽  
Paternal Age ◽  
Offspring Sex Ratio ◽  
Offspring Sex

scholarly journals Opioid Literacy in an Immigrant Group in Rural Area: Use of Social Determinant of Health Framework

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 397-397
Author(s):  
Hee Yun Lee ◽  
Eun Young Choi ◽  
Jieun Song ◽  
Jamie Gajos ◽  
Yan Luo
Keyword(s):  
Older Adults ◽  
Young Adults ◽  
Health Literacy ◽  
Rural Area ◽  
Limited English Proficiency ◽  
English Proficiency ◽  
Age Groups ◽  
Social Determinant ◽  
Opioid Overdose ◽  
Middle Aged

Abstract Opioid overdose risk is particularly high in immigrant communities partly due to limited English proficiency (Guarino et al., 2015). Previous studies reported that social determinants of health (SDH) have been associated with risk for opioid overdose (Dasgupta et al., 2018). The current study examines the association between SDH and literacy of opioid overdose risk among the immigrant population living in a rural area. Specifically, we examine the association in various age groups including young adults (aged 20 to 34), middle-aged (aged 35 to 49), and older adults (ages 50 to 75). Data were drawn from a sample of Korean American immigrants residing in rural Alabama (N=225). The participants administered the Brief Opioid Knowledge (BOOK) Questionnaire (Dunn et al., 2016). Multiple regression analyses were conducted for three age groups to identify predictors of opioid literacy. Overall, older adults had lower levels of opioid literacy relative to their younger counterparts. Among young adults, low English proficiency, more chronic conditions, and greater depressive symptoms were significant predictors of limited opioid literacy. For the middle-aged adults, lower levels of health literacy and more pain symptoms were associated with limited opioid literacy. Among older adults, women, those with higher English proficiency, and lower health literacy had lower levels of opioid literacy. The findings demonstrated a greater vulnerability of older immigrants to limited opioid literacy. Different predictors based on SDH of limited opioid literacy across age groups have implications for tailored health promotion strategies to reduce opioid overdose risk.

scholarly journals Sex Chromosome Meiotic Drive in Stalk-Eyed Flies

Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1169-1180 ◽  
Author(s):  
Daven C Presgraves ◽  
Emily Severance ◽  
Gerald S Willrinson
Keyword(s):  
Sex Ratio ◽  
Sex Chromosome ◽  
Sex Ratios ◽  
Natural Populations ◽  
Meiotic Drive ◽  
Operational Sex Ratio ◽  
Genetic Modifiers ◽  
Ratio Distortion ◽  
The Impact ◽  
Sex Ratio Distortion

Meiotically driven sex chromosomes can quickly spread to fixation and cause population extinction unless balanced by selection or suppressed by genetic modifiers. We report results of genetic analyses that demonstrate that extreme female-biased sex ratios in two sister species of stalk-eyed flies, Cyrtodiopsis dalmanni and C. whitei, are due to a meiotic drive element on the X chromosome (Xd). Relatively high frequencies of Xd in C. dalmanni and C. whitei (13–17% and 29%, respectively) cause female-biased sex ratios in natural populations of both species. Sex ratio distortion is associated with spermatid degeneration in male carriers of Xd. Variation in sex ratios is caused by Y-linked and autosomal factors that decrease the intensity of meiotic drive. Y-linked polymorphism for resistance to drive exists in C. dalmanni in which a resistant Y chromosome reduces the intensity and reverses the direction of meiotic drive. When paired with Xd, modifying Y chromosomes (Ym) cause the transmission of predominantly Y-bearing sperm, and on average, production of 63% male progeny. The absence of sex ratio distortion in closely related monomorphic outgroup species suggests that this meiotic drive system may predate the origin of C. whitei and C. dalmanni. We discuss factors likely to be involved in the persistence of these sex-linked polymorphisms and consider the impact of Xd on the operational sex ratio and the intensity of sexual selection in these extremely sexually dimorphic flies.

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