scholarly journals The impact of sex ratio and economic status on local birth rates

2013 ◽  
Vol 9 (2) ◽  
pp. 20130027 ◽  
Author(s):  
A. Chipman ◽  
E. Morrison
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Economic Status ◽  
Life History Strategy ◽  
Reproductive Behaviour ◽  
Female Competition ◽  
Birth Rates ◽  
Economically Deprived ◽  
Human Mating ◽  
The Impact

Human mating and reproductive behaviour can vary depending on various mechanisms, including the local sex ratio. Previous research shows that as sex ratios become female-biased, women from economically deprived areas are less likely to delay reproductive opportunities to wait for a high-investing mate but instead begin their reproductive careers sooner. Here, we show that the local sex ratio also has an impact on female fertility schedules. At young ages, a female-biased ratio is associated with higher birth rates in the poorest areas, whereas the opposite is true for the richest areas. At older ages, a female-biased ratio is associated with higher birth rates in the richest, but not the poorest areas. These patterns suggest that female–female competition encourages poorer women to adopt a fast life-history strategy and give birth early, and richer women to adopt a slow life-history strategy and delay reproduction.

Life history variation in Celleporella hyalina (Bryozoa)

1986 ◽  
Vol 228 (1251) ◽  
pp. 127-132 ◽  
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Sex Ratio ◽  
Water Flow ◽  
Reproductive Output ◽  
Life History Strategy ◽  
Colony Growth ◽  
Allocation Of Resources ◽  
Life History Variation ◽  
Male And Female

In colonies of the cheilostome bryozoan Celleporella hyalina (L.), water flow regime has a significant effect on colony growth rate and, indirectly, on the number of reproductive zooids produced. Higher growth rates occur under conditions of higher water flow. Sex ratio and reproductive output are not, however, significantly affected. Colonies of different genotypes show significant differences in their reproductive versus somatic investment, and in their allocation of resources to male and female functions. There is therefore genetically based variation in life history strategy within the population of colonies. This variation may reflect limitation of normalizing selection imposed by microenvironmental variability.

scholarly journals Life History, Fertility, and Short-Term Mating Motivation

2018 ◽  
Vol 16 (3) ◽  
pp. 147470491880006 ◽  
Author(s):  
Aekyoung Kim ◽  
Hannah Bradshaw ◽  
Kristina M. Durante ◽  
Sarah E. Hill
Keyword(s):  
Life History ◽  
Early Life ◽  
Life History Strategy ◽  
Single Women ◽  
Relationship Status ◽  
Cycle Phase ◽  
High Fertility ◽  
Ovulatory Cycle ◽  
Short Term ◽  
The Impact

The current research examines the impact of women’s early-life socioeconomic status (SES; used as a proxy measure of life history strategy), relationship status, and ovulatory cycle phase on their desire for short-term mating. Results revealed that during the periovulatory phase (i.e., the high-fertility phase of the monthly ovulatory cycle), single women from low SES environments expressed an increased desire for short-term mating, whereas the opposite was found for single women from high SES environments. No such pattern was found for partnered women. These results suggest that one’s early-life environment and relationship status may play a key role in how women respond to internal fertility cues, providing important new insights into factors that may moderate ovulatory shifts in mating behavior. Results provide some of the first evidence that one’s developmental history may alter the expression of ovulatory cycle adaptations.

Host B chromosomes as potential sex ratio distorters of intestinal nematode infrapopulations in the yellow-necked mouse (Apodemus flavicollis)

2018 ◽  
Vol 93 (05) ◽  
pp. 552-558
Author(s):  
V.M. Jovanović ◽  
B. Čabrilo ◽  
I. Budinski ◽  
O. Bjelić-Čabrilo ◽  
T. Adnađević ◽  
...  
Keyword(s):  
Life History ◽  
Sex Ratio ◽  
Sex Ratios ◽  
Life History Strategy ◽  
B Chromosomes ◽  
Published Data ◽  
Apodemus Flavicollis ◽  
Egg Hatching ◽  
Trichuris Muris ◽  
Yellow Necked Mouse

AbstractThe yellow-necked mouse, Apodemus flavicollis, can be considered as a model for genetic polymorphism produced by the frequent presence of supernumerary or B chromosomes (Bs). Host genetic background is rarely taken into account in studies of parasite sex ratio. The main aim of this study was to investigate the range of infrapopulation sex ratios for nematode parasites of the yellow-necked mouse and to determine which factors most influence variation in parasite sex ratios. Six nematode species found in the collected yellow-necked mice were analysed. We confirmed the predominant pattern of female-biased sex ratios in vertebrate parasite infrapopulations. The presence of B chromosomes in host genomes played an important role in infrapopulations of Heligmosomoides polygyrus, Syphacia stroma and Trichuris muris, as hosts with B chromosomes carried a higher proportion of males. The relative increase of males in infrapopulations could result from a shift in parasite life history strategy, induced by adaptation to the specific host genotypes (Bs present). In a meta-analysis with previously published data, the sex determination system was demonstrated to play a significant role in nematode sex ratio variation, as well as specific life history patterns, such as the place of egg hatching.

scholarly journals The Impact of Socio-Economic Status, Life-History, and Biological Sex on Affective Empathy

2021 ◽  
Author(s):  
Shadow Love ◽  
Whitney Whitaker
Keyword(s):  
Life History ◽  
Online Survey ◽  
Economic Status ◽  
Income Level ◽  
High Income ◽  
Affective Empathy ◽  
Factorial Anova ◽  
Biological Sex ◽  
Amazon's Mechanical Turk ◽  
The Impact

<div>The current study examined a gap in prior research by examining the interaction between socioeconomic status, life-history, biological sex, and affective empathy. Participants (N = 504; Mage = 37; 64% biological sex male; 69% White/Caucasian) were recruited using Amazon’s Mechanical Turk and completed an online survey to assess the main variables of interest. Two 2x2x3 factorial ANOVA(s) were conducted. Significant main effects and interactions were found; however, the findings were qualified by a significant three-way interaction [F (2, 491) = 3.18, p = .04, partial η2 = .01]. Participants who reported being biological sex male as well as having a high-income level and slower life-history (more social support) reported slightly more affective empathy (M = 3.65, SE = .08) than male participants reporting a high-income level but faster life-history (M = 3.22, SE = .08). However, there were no significant differences when comparing biological sex female participants across levels of SES and life-history. Implications of the current findings are discussed.<br><div><br></div></div>

scholarly journals Disease mediated changes to life history and demography threaten the survival of European amphibian populations

2017 ◽  
Author(s):  
Lewis J. Campbell ◽  
Trenton W. J. Garner ◽  
Giulia Tessa ◽  
Benjamin C. Scheele ◽  
Amber G.F. Griffiths ◽  
...  
Keyword(s):  
Life History ◽  
Infectious Diseases ◽  
Rana Temporaria ◽  
Life History Strategy ◽  
Adult Mortality ◽  
Population Declines ◽  
Individual Level ◽  
Historical Presence ◽  
Population Demographic ◽  
The Impact

AbstractInfectious diseases can influence the life history strategy of their hosts and such influences subsequently impact the demography of infected populations, reducing viability independently of increased mortality or morbidity. Amphibians are the most threatened group of vertebrates and emerging infectious diseases play a large role in their population declines. Viruses of genus Ranavirus are responsible for one of the deadliest of these diseases. To date no work has evaluated the impact of ranaviruses on host life-history post metamorphosis or population demographic structure at the individual level. In this study, we used skeletochronology and morphology to evaluate the impact of ranaviruses on the demography of populations of European common frog (Rana temporaria) in the United Kingdom. We compared ecologically similar populations that differed only in their historical presence or absence of ranaviral disease. Our results suggest that ranaviruses are associated with shifts in the age structure of infected populations, potentially caused by increased adult mortality and associated shifts in the life history of younger age classes. Population projection models indicate that such age truncation could heighten the vulnerability of frog populations to stochastic environmental challenges. Our individual level data provide further compelling evidence that the emergence of infectious diseases can alter host demography, subsequently increasing population vulnerability to additional stressors.

scholarly journals CLASH: Climate (change) and cultural evolution of intergroup conflict

2017 ◽  
Vol 21 (3) ◽  
pp. 457-471 ◽  
Author(s):  
Paul A. M. van Lange ◽  
Maria I. Rinderu ◽  
Brad J. Bushman
Keyword(s):  
Climate Change ◽  
Life History ◽  
Seasonal Variation ◽  
Theoretical Model ◽  
Income Inequality ◽  
Cultural Evolution ◽  
Life History Strategy ◽  
Self Control ◽  
Intergroup Conflict ◽  
The Impact

Aggression and violence levels generally increase as one moves closer to the equator, but why? We developed a new theoretical model, CLimate, Aggression, and Self-control in Humans (CLASH; van Lange, Rinderu, & Bushman, 2017b, 2017c), to understand differences within and between countries in aggression and violence in terms of differences in climate. Colder temperatures, and especially larger degrees of seasonal variation in climate, call for individuals and groups to adopt a slower life history strategy, revealed in a greater focus on the future (vs. present) and a stronger focus on self-control—variables that are known to inhibit aggression and violence. Other variables (e.g., wealth, income inequality, parasite stress) are also linked to both climate differences and to aggression and violence differences. When people think of the consequences of climate change, they rarely think of the impact on aggression and violence levels, but they should. CLASH has broad implications for the effects of climate change on intergroup conflict.

scholarly journals Mate Preferences and Their Behavioral Manifestations

2019 ◽  
Vol 70 (1) ◽  
pp. 77-110 ◽  
Author(s):  
David M. Buss ◽  
David P. Schmitt
Keyword(s):  
Life History Strategy ◽  
Mate Preferences ◽  
Cultural Norms ◽  
Causal Process ◽  
Sexual Strategies ◽  
Sexual Regret ◽  
Context Specific ◽  
Mating Psychology ◽  
Human Mating ◽  
The Impact

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.

scholarly journals The Impact of Socio-Economic Status, Life-History, and Biological Sex on Affective Empathy

2021 ◽  
Author(s):  
Shadow Love ◽  
Whitney Whitaker
Keyword(s):  
Life History ◽  
Online Survey ◽  
Economic Status ◽  
Income Level ◽  
High Income ◽  
Affective Empathy ◽  
Factorial Anova ◽  
Biological Sex ◽  
Amazon's Mechanical Turk ◽  
The Impact

<div>The current study examined a gap in prior research by examining the interaction between socioeconomic status, life-history, biological sex, and affective empathy. Participants (N = 504; Mage = 37; 64% biological sex male; 69% White/Caucasian) were recruited using Amazon’s Mechanical Turk and completed an online survey to assess the main variables of interest. Two 2x2x3 factorial ANOVA(s) were conducted. Significant main effects and interactions were found; however, the findings were qualified by a significant three-way interaction [F (2, 491) = 3.18, p = .04, partial η2 = .01]. Participants who reported being biological sex male as well as having a high-income level and slower life-history (more social support) reported slightly more affective empathy (M = 3.65, SE = .08) than male participants reporting a high-income level but faster life-history (M = 3.22, SE = .08). However, there were no significant differences when comparing biological sex female participants across levels of SES and life-history. Implications of the current findings are discussed.<br><div><br></div></div>

Sign in / Sign up

Export Citation Format

Share Document