Religious Geography and County‐Level Sex Ratios in China Tong, Yunping; Sennott, Christie; Yang, Fenggang
Journal for the scientific study of religion,
March 2021, 2021-03-00, 20210301, Letnik:
60, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The sex ratio at birth in China is highly imbalanced in favor of boys. Past research on sex ratios in China emphasizes economic factors for their weakening effect on the Confucian tradition of son ...preference. Research in the sociology of religion suggests that religious geography may affect sex ratios through the spill‐over of religious teachings to those living in areas dominated by a religious tradition. To assess this linkage, we investigate the relationship between religious geography and county‐level child sex ratios using the 2000 China Population Census and the 2004 China Economic Census, the most complete and recent data available on religious presence in China. Applying spatial analyses of 2,685 counties (over 90% of all counties), we find that counties with a greater presence of Daoist temples have more imbalanced (male‐biased) sex ratios, whereas a greater presence of Buddhist temples and Islamic mosques is associated with less imbalanced sex ratios.
Most ecological processes now show responses to anthropogenic climate change. In terrestrial, freshwater, and marine ecosystems, species are changing genetically, physiologically, morphologically, ...and phenologically and are shifting their distributions, which affects food webs and results in new interactions. Disruptions scale from the gene to the ecosystem and have documented consequences for people, including unpredictable fisheries and crop yields, loss of genetic diversity in wild crop varieties, and increasing impacts of pests and diseases. In addition to the more easily observed changes, such as shifts in flowering phenology, we argue that many hidden dynamics, such as genetic changes, are also taking place. Understanding shifts in ecological processes can guide human adaptation strategies. In addition to reducing greenhouse gases, climate action and policy must therefore focus equally on strategies that safeguard biodiversity and ecosystems.
Males and females often have different roles in reproduction, although the origin of these differences has remained controversial. Explaining the enigmatic reversed sex roles where males sacrifice ...their mating potential and provide full parental care is a particularly long-standing challenge in evolutionary biology. While most studies focused on ecological factors as the drivers of sex roles, recent research highlights the significance of social factors such as the adult sex ratio. To disentangle these propositions, here, we investigate the additive and interactive effects of several ecological and social factors on sex role variation using shorebirds (sandpipers, plovers, and allies) as model organisms that provide the full spectrum of sex role variation including some of the best-known examples of sex-role reversal. Our results consistently show that social factors play a prominent role in driving sex roles. Importantly, we show that reversed sex roles are associated with both male-skewed adult sex ratios and high breeding densities. Furthermore, phylogenetic path analyses provide general support for sex ratios driving sex role variations rather than being a consequence of sex roles. Together, these important results open future research directions by showing that different mating opportunities of males and females play a major role in generating the evolutionary diversity of sex roles, mating system, and parental care.
Research on the association between armed conflict and son preference has largely been based on single-country studies, often presenting descriptive patterns. This paper empirically analyzes the ...association between conflict and son preference using a sample of more than 1.1 million individuals from 58 countries over the period 2003–2018. We empirically show that both the incidence and intensity of conflict exposure are associated with greater son preference. Moreover, conflict-exposed individuals are likely to realise their preference for sons, as reflected in the systematically higher prevalence of sons over daughters among these individuals. To explore the aggregate effects of these findings, we conduct a cross-country analysis of sex ratios and show that history of conflict exposure plays an important role in explaining the cross-country differences in sex ratios.
•This article tests the association between conflict and son preference using a sample of 1.1 million individuals from 58 countries over the period 2003–2018.•We show that both incidence and intensity of conflict exposure are associated with greater son preference leading to higher prevalence of sons over daughters.•Macro-data analysis shows that history of conflict exposure plays an important role in explaining the cross-country differences in sex ratios.
The black soldier fly (BSF), Hermetia illucens (L., 1758) (Diptera: Stratiomyidae), is an endemic fly species from the tropical, subtropical and warm temperate zones of America. This saprophagous ...species relies on its environment where it finds the decomposing matter for the larvae to grow. The polyphagous diet and the macronutrient quality (mainly lipids and proteins) of these larvae make them excellent candidates for various applications such as waste and organic material management, incorporation in animal feed or alternative energy source. Although rearing development in temperate regions requires artificial processes to continuously produce high quality eggs and larvae, few studies have been conducted on the mating and oviposition processes governing H. illucens reproduction. Research conducted in semi-artificial rearing conditions showed that the number of mating varied according to the season. It has been speculated that this behavior could be due to differences in the intensity of sunlight caused by the change of seasons. This study aims at evaluating the influence of sex-ratio, density and nycthemeral cycle on H. illucens reproduction. In order to tackle this issue, an artificial set up for oviposition to collect eggs has been developed. This egg collection system aims at centralize oviposition and simplify eggs collection. Two populations with opposite sex-ratio (male-dominant and female-dominant) were selected. Their respective eggs productions have been evaluated for five breeding densities. Eggs weights varied significantly among the densities for each opposite sex-ratio population and female dominant population produced most eggs weight from 6500 individuals /m3. Finally, four nycthemeral cycles (2, 6, 12 and 18h of daily light) were simulated to evaluate the impact of light duration on reproduction. Early oviposition pic associated with a decrease of the oviposition period are shown when H. illucens are exposed to increasing light duration. These experiments enable improvement of the understanding on artificial reproduction of H. illucens.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
AbstractObjectiveTo compare established associations between risk factors and mortality in UK Biobank, a study with an exceptionally low rate of response to its baseline survey, against those from ...representative studies that have conventional response rates.DesignProspective cohort study alongside individual participant meta-analysis of other cohort studies.SettingUnited Kingdom.ParticipantsAnalytical sample of 499 701 people (response rate 5.5%) in analyses in UK Biobank; pooled data from the Health Surveys for England (HSE) and the Scottish Health Surveys (SHS), including 18 studies and 89 895 people (mean response rate 68%). Both study populations were linked to the same nationwide mortality registries, and the baseline age range was aligned at 40-69 years.Main outcome measureDeath from cardiovascular disease, selected malignancies, and suicide. To quantify the difference between hazard ratios in the two studies, a ratio of the hazard ratios was used with HSE-SHS as the referent.ResultsRisk factor levels and mortality rates were typically more favourable in UK Biobank participants relative to the HSE-SHS consortium. For the associations between risk factors and mortality endpoints, however, close agreement was seen between studies. Based on 14 288 deaths during an average of 7.0 years of follow-up in UK Biobank and 7861 deaths over 10 years of mortality surveillance in HSE-SHS, for cardiovascular disease mortality, for instance, the age and sex adjusted hazard ratio for ever having smoked cigarettes (versus never) was 2.04 (95% confidence interval 1.87 to 2.24) in UK Biobank and 1.99 (1.78 to 2.23) in HSE-SHS, yielding a ratio of hazard ratios close to unity (1.02, 0.88 to 1.19). The overall pattern of agreement between studies was essentially unchanged when results were compared separately by sex and when baseline years and censoring dates were aligned.ConclusionDespite a very low response rate, risk factor associations in the UK Biobank seem to be generalisable.
Abstract
As an important domain of evolutionary ecology, sex allocation theory well explains the evolution of investment into female versus male offspring. Local mate competition (LMC) is a good ...predictor of sex allocation, where the optimal sex ratio becomes less female-biased and asymptotically approaches 0.5 as the number of foundresses increases. Parasitoid wasps, with haplodiploid sex determination, offer excellent opportunities to test how organisms manipulate their offspring sex ratio in response to environmental variation, and many species have been proved to allocate sex according to predictions under LMC. When hosts are spatially clustered, as in gregarious species, the mating systems of quasi-gregarious parasitoids meet the essential assumptions (female mating before dispersal) of LMC. However, inconsistent with predictions, in the quasi-gregarious species Anastatus disparis (Hymenoptera: Eupelmidae), a strongly female-biased eclosion sex ratio (0.156 ± 0.018 to 0.185 ± 0.016) was observed as the number of females laying eggs in a patch increased. Superparasitism, in which 44.7% of parasitized hosts contained more than one egg but only one adult emerged from each host, was common in A. disparis. However, the egg sex ratio was determined by microsatellites and likely fit the predictions of LMC theory. Male-biased offspring mortality arising from superparasitism during development likely contributes to the shift from the primary sex ratio predicted under LMC to the observed female-biased eclosion sex ratio. Inconsistent with results in gregarious parasitoids, the role of superparasitism in driving sex ratio shifts in quasi-gregarious parasitoids should be incorporated into LMC-based predictions of sex ratios.
In a partly social parasitoid wasps, females produce more male-biased egg sex ratios as the number of egg-laying females increases, in line with the predictions of local mate competition (LMC) theory. However, we found a strong female bias in eggs that hatched. Superparasitism during development likely contributes to the shift from the primary sex ratio predicted under LMC theory to the observed female-biased hatching sex ratio.
Sex roles describe sex differences in courtship, mate competition, social pair‐bonds and parental care. A key challenge is to identify associations among the components and the drivers of sex roles. ...Here, we investigate sex roles using data from over 1800 bird species. We found extensive variation and lability in proxies of sex roles, indicating remarkably independent evolution among sex role components. Climate and life history showed weak associations with sex roles. However, adult sex ratio is associated with sexual dimorphism, mating system and parental care, suggesting that social environment is central to explaining variation in sex roles among birds. Our results suggest that sex differences in reproductive behaviour are the result of diverse and idiosyncratic responses to selection. Further understanding of sex roles requires studies at the population level to test how local responses to ecology, life histories and mating opportunities drive processes that shape sex role variation among higher taxa.
Sex roles describe sex differences in courtship, mate competition, social pair‐bonds and parental care. A key challenge is to identify associations among the components and the drivers of sex roles. We found extensive variation and lability in proxies of sex roles, indicating remarkably independent evolution among sex role components, and that the social environment is central to explaining variation in sex roles among birds.
This paper contributes to the verification of the Trivers–Willard hypothesis (TWH). Based on the TWH, observed sex (male-to-female) ratio at birth in a population is presumed to decline when parents ...experience economic stress. The empirical evidence so far is mixed.
The research material consisted of data on the total numbers of live male and female births in the Polish population in the years 1995–2020. The data were used to produce semiannual time series for secondary sex ratio (SSR), and the sex ratio at birth (SRB). The variable describing the economic stress of households was percentage change in private consumption. The statistical method proposed by Catalano and Bruckner – expanded to include additional statistical analyses – was applied to retest the economic stress hypothesis. The analysis led to complementary ARMAX models, explaining SSR or SRB variance based on autoregression and the moving average process, as well as private consumption. The results indicate that periods of decreasing consumption favored mothers having daughters, while periods of increasing consumption favored mothers having sons. The number of “additional” male births resulting from improved economic conditions was calculated for the period of study. Consequently, the economic factor was shown to have a positive effect on the human sex ratio. At the same time, it should be noted that SSR and SRB reaction lags to consumption changes were different for Łódzkie Province (one year) and for Poland (two years).
The obtained results led to the “correct” verification of the Trivers–Willard hypothesis (TWH): economic stress affected the SSR and SRB in Poland. Both SSR and SRB were useful in analyzing economic stress (a dual solution). The use of a greater density of data points was shown to improve analysis effects and increase the likelihood of a “positive” verification of the economic stress hypothesis.
Evolved mate preferences comprise a central causal process in Darwin's theory of sexual selection. Their powerful influences have been documented in all sexually reproducing species, including in ...sexual strategies in humans. This article reviews the science of human mate preferences and their myriad behavioral manifestations. We discuss sex differences and sex similarities in human sexual psychology, which vary according to short-term and long-term mating contexts. We review context-specific shifts in mating strategy depending on individual, social, and ecological qualities such as mate value, life history strategy, sex ratio, gender economic inequality, and cultural norms. We review the empirical evidence for the impact of mate preferences on actual mating decisions. Mate preferences also dramatically influence tactics of mate attraction, tactics of mate retention, patterns of deception, causes of sexual regret, attraction to cues to sexual exploitability, attraction to cues to fertility, attraction to cues to resources and protection, derogation of competitors, causes of breakups, and patterns of remarriage. We conclude by articulating unresolved issues and offer a future agenda for the science of human mating, including how humans invent novel cultural technologies to better implement ancient sexual strategies and how cultural evolution may be dramatically influencing our evolved mating psychology.
PDF
