The influence of harshness and unpredictability on female sexual development: Addressing gene–environment interplay using a polygenic score

2021 ◽  
pp. 1-11
Author(s):  
Gabriel L. Schlomer ◽  
Qi Sun
Keyword(s):  
Life History ◽  
Sexual Intercourse ◽  
Life History Theory ◽  
Path Model ◽  
Life History Strategies ◽  
Age At Menarche ◽  
Developmental Models ◽  
Polygenic Score ◽  
First Sexual Intercourse ◽  
Gene Environment

Abstract Recent developments in the application life history theory to human development indicate two fundamental dimension of the early environment – harshness and unpredictability – are key regulators life history strategies. Few studies have examined the manner with which these dimensions influence development, though age at menarche (AAM) and age at first sexual intercourse have been proposed as possible mechanisms among women. Data from the Avon Longitudinal Study of Parents and Children (N = 3,645) were used to examine direct and indirect effects of harshness (financial difficulties) and unpredictability (paternal transitions) on lifetime and past year sexual partners during adolescence and young adulthood. Genetic confounding was addressed using an AAM polygenic score (PGS) and potential gene-by-environment interactions were also evaluated using the PGS. Path model results showed only harshness was directly related to AAM. Harshness, unpredictability, and AAM were indirectly related to lifetime and past year sexual partner number via age at first sexual intercourse. The PGS did not account for any of the associations and no significant interactions were detected. Implications of these results for developmental models derived from life history theory are discussed as well as the role of PGSs in gene–environment interplay research.

scholarly journals The effects of age at menarche and first sexual intercourse on reproductive and behavioural outcomes: a Mendelian randomization study

2018 ◽  
Author(s):  
Rebecca B Lawn ◽  
Hannah M Sallis ◽  
Robyn E Wootton ◽  
Amy E Taylor ◽  
Perline Demange ◽  
...  
Keyword(s):  
Life History ◽  
Sexual Intercourse ◽  
Life History Theory ◽  
Mendelian Randomization ◽  
Causal Effect ◽  
Life History Strategies ◽  
Age At Menarche ◽  
Age At First Birth ◽  
Risky Behaviour ◽  
First Sexual Intercourse

SummaryThere is substantial variation in the timing of significant reproductive life events such as menarche and first sexual intercourse. Life history theory explains this variation as an adaptive response to the developmental environment. In environments characterized by harsh conditions, adopting a fast life history strategy may increase fitness. In line with this, there is evidence demonstrating that greater childhood adversity is associated with earlier age at menarche. Here we applied Mendelian randomization (MR) methods to investigate whether there is a causal effect of variation in age at menarche and age at first sexual intercourse on outcomes related to reproduction, education and risky behaviour in UK Biobank (N = 114883–181,255). Our results suggest that earlier age at menarche affects some traits that characterize life history strategies including earlier age at first and last birth, decreased educational attainment, and decreased age at leaving education (for example, we found evidence for a 0.26 year decrease in age at first birth per year decrease in age at menarche, 95% confidence interval: −0.34 to −0.17; p < 0.0001). We find no clear evidence of effects of age at menarche on other outcomes, such as risk taking behaviour. Age at first sexual intercourse was also related to many life history outcomes, although there was evidence of horizontal pleiotropy which violates an assumption of MR and results should be treated with caution. Taken together, these results highlight how MR can be applied to test predictions of life history theory and to better understand determinants of health and social behaviour.

Sexual size dimorphism and life history traits in an island-mainland system: an overview of the lizard genus Microlophus

2021 ◽  
pp. 1-7
Author(s):  
Ken S. Toyama ◽  
Christopher K. Boccia
Keyword(s):  
Life History ◽  
South America ◽  
Life History Theory ◽  
Life History Traits ◽  
Sexual Size Dimorphism ◽  
Life History Strategies ◽  
Galápagos Islands ◽  
Size Dimorphism ◽  
Rensch's Rule ◽  
Comprehensive Compilation

Abstract Opposing life history strategies are a common result of the different ecological settings experienced by insular and continental species. Here we present a comprehensive compilation of data on sexual size dimorphism (SSD) and life history traits of Microlophus, a genus of lizards distributed in western South America and the Galápagos Islands, and test for differences between insular and continental species under life history theory expectations. Contrary to our predictions, we found no differences in SSD between localities or evidence that Microlophus follows Rensch’s rule. However, as expected, head dimensions and maturity sizes were significantly larger in insular species while continental species had larger clutches. Our results show that Microlophus exhibits some of the patterns expected from an island-mainland system, but unexplained patterns will only be resolved through future ecological, morphological and behavioural studies integrating both faunas.

Life History Strategies

2018 ◽  
pp. 95-126
Author(s):  
Marco Del Giudice
Keyword(s):  
Life History ◽  
Individual Differences ◽  
Life History Theory ◽  
Human Life ◽  
Life History Strategy ◽  
Current Theory ◽  
Life History Strategies ◽  
Extended Model ◽  
Life History Variation ◽  
Basic Model

The chapter introduces the basics of life history theory, the concept of life history strategy, and the fast–slow continuum of variation. After reviewing applications to animal behavior and physiology, the chapter reviews current theory and evidence on individual differences in humans as manifestations of alternative life history strategies. The chapter first presents a “basic model” of human life history–related traits, then advances an “extended model” that identifies multiple cognitive-behavioral profiles within fast and slow strategies. Specifically, it is proposed that slow strategies comprise prosocial/caregiving and skilled/provisioning profiles, whereas fast strategies comprise antisocial/exploitative and seductive/creative profiles. The chapter also reviews potential neurobiological markers of life history variation and considers key methodological issues in this area.

scholarly journals Cuckoos, cowbirds and hosts: adaptations, trade-offs and constraints

2006 ◽  
Vol 362 (1486) ◽  
pp. 1873-1886 ◽  
Author(s):  
Oliver Krüger
Keyword(s):  
Life History ◽  
Brood Parasitism ◽  
Reproductive Strategies ◽  
Life History Theory ◽  
Model Systems ◽  
Life History Strategies ◽  
Host System ◽  
Brood Parasites ◽  
Trade Offs ◽  
Evolution Of Life

The interactions between brood parasitic birds and their host species provide one of the best model systems for coevolution. Despite being intensively studied, the parasite–host system provides ample opportunities to test new predictions from both coevolutionary theory as well as life-history theory in general. I identify four main areas that might be especially fruitful: cuckoo female gentes as alternative reproductive strategies, non-random and nonlinear risks of brood parasitism for host individuals, host parental quality and targeted brood parasitism, and differences and similarities between predation risk and parasitism risk. Rather than being a rare and intriguing system to study coevolutionary processes, I believe that avian brood parasites and their hosts are much more important as extreme cases in the evolution of life-history strategies. They provide unique examples of trade-offs and situations where constraints are either completely removed or particularly severe.

scholarly journals Increased Vulnerability to Pregnancy and Sexual Violence in Adolescents with Precocious Menstruation

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Giani Silvana Schwengber Cezimbra ◽  
Dioclécio Campos Junior ◽  
Edward Araujo Júnior ◽  
Cristina Aparecida Falbo Guazzelli ◽  
Álvaro Nagib Atallah
Keyword(s):  
Sexual Violence ◽  
Sexual Intercourse ◽  
Statistical Tests ◽  
Strong Association ◽  
Sexual Initiation ◽  
Age At Menarche ◽  
Health Unit ◽  
Cross Sectional ◽  
First Sexual Intercourse ◽  
Adolescent Population

This cross-sectional, observational, and descriptive study was conducted to evaluate the association between age at menarche in the adolescent population and the age at sexual initiation, age at first pregnancy, and experience of sexual violence in the adolescent population visiting a primary health unit in Brazil. We recruited 201 female adolescents who visited the gynecology outpatient clinic of a Basic Health Unit in the Federal District of Brazil. These adolescents answered a questionnaire with regard to sexual and reproductive health during doctor’s appointments. To calculate the association, we recorded data for age at menarche, age at first sexual intercourse, age at first pregnancy, and experience of sexual violence. Pearson and Mann–Whitney correlation coefficient statistical tests were performed to evaluate the association between these variables. Mean age at menarche was lower among adolescents who became pregnant (p=0.0004) and those who experienced sexual violence (p=0.0008). Further, there was a strong association between age at menarche and age at first sexual intercourse (p<0.0001). This study also demonstrated that the earlier the age at menarche, the earlier was the age at sexual initiation and age at first unintended pregnancy and the greater was the risk of experiencing sexual violence. Early menarche may be considered a vulnerability factor during adolescence.

Maternal Relationships With Adolescents

2021 ◽  
pp. 264-279
Author(s):  
Jamie M. Gajos ◽  
Kevin M. Beaver
Keyword(s):  
Life History ◽  
Life History Theory ◽  
Future Research ◽  
Evolutionary Perspective ◽  
Theoretical Frameworks ◽  
Reciprocal Relationships ◽  
Gene Environment ◽  
Adolescent Conflict ◽  
The Relationship ◽  
Theory Framework

This chapter studies a number of theoretical frameworks which seek to explain the reciprocal relationships between mothers and adolescents. In particular, it discusses two primary explanations for the onset of mother–adolescent conflict during puberty. The first explanation is informed by an evolutionary perspective and contains two different hypotheses of the relationship between familial conflict and puberty. The first hypothesis applies a general evolutionary theory framework to explain the relationship between maternal–adolescent conflict and puberty by suggesting that the onset of conflict during the pubescent years functions to increase (ancestral) offspring reproductive fitness. The second evolutionary hypothesis for the familial conflict–puberty relationship is informed by a life history theory perspective. Meanwhile, the second explanation for mother–adolescent conflict is informed by an area of research devoted to examining person-directed effects, which are commonly referred to as gene–environment correlations. The chapter then offers a number of recommendations for future research on the relationships between mothers and adolescents.

scholarly journals Differential reproductive responses to stress reveal the role of life-history strategies within a species

2013 ◽  
Vol 280 (1771) ◽  
pp. 20132090 ◽  
Author(s):  
J. Schultner ◽  
A. S. Kitaysky ◽  
G. W. Gabrielsen ◽  
S. A. Hatch ◽  
C. Bech
Keyword(s):  
Life History ◽  
Life History Theory ◽  
Life History Strategies ◽  
Short Term ◽  
Food Shortages ◽  
Investment In Reproduction ◽  
Response To Stress ◽  
Environmental Events ◽  
Two Populations

Life-history strategies describe that ‘slow’- in contrast to ‘fast’-living species allocate resources cautiously towards reproduction to enhance survival. Recent evidence suggests that variation in strategies exists not only among species but also among populations of the same species. Here, we examined the effect of experimentally induced stress on resource allocation of breeding seabirds in two populations with contrasting life-history strategies: slow-living Pacific and fast-living Atlantic black-legged kittiwakes. We tested the hypothesis that reproductive responses in kittiwakes under stress reflect their life-history strategies. We predicted that in response to stress, Pacific kittiwakes reduce investment in reproduction compared with Atlantic kittiwakes. We exposed chick-rearing kittiwakes to a short-term (3-day) period of increased exogenous corticosterone (CORT), a hormone that is released during food shortages. We examined changes in baseline CORT levels, parental care and effects on offspring. We found that kittiwakes from the two populations invested differently in offspring when facing stress. In response to elevated CORT, Pacific kittiwakes reduced nest attendance and deserted offspring more readily than Atlantic kittiwakes. We observed lower chick growth, a higher stress response in offspring and lower reproductive success in response to CORT implantation in Pacific kittiwakes, whereas the opposite occurred in the Atlantic. Our findings support the hypothesis that life-history strategies predict short-term responses of individuals to stress within a species. We conclude that behaviour and physiology under stress are consistent with trade-off priorities as predicted by life-history theory. We encourage future studies to consider the pivotal role of life-history strategies when interpreting inter-population differences of animal responses to stressful environmental events.

scholarly journals Life-history traits and description of the new gonochoric amphimictic Mesobiotus joenssoni (Eutardigrada: Macrobiotidae) from the island of Elba, Italy

2019 ◽  
Author(s):  
Roberto Guidetti ◽  
Elisa Gneuß ◽  
Michele Cesari ◽  
Tiziana Altiero ◽  
Ralph O Schill
Keyword(s):  
Life History ◽  
Life History Theory ◽  
Life History Traits ◽  
Life Cycles ◽  
Life History Strategies ◽  
Egg Hatching ◽  
Body Segments ◽  
Hatching Time ◽  
Laboratory Cultures ◽  
The Mean

Abstract Comparative analyses of life-history theory studies are based on the characteristics of the life cycles of different species. For tardigrades, life-history traits are available only from laboratory cultures, most of which have involved parthenogenetic species. The discovery of a new gonochoristic bisexual Mesobiotus species in a moss collected on the island of Elba (Italy) provides us with the opportunity to describe Mesobiotus joenssoni sp. nov. and to collect data on the life-history traits of cultured specimens to increase our knowledge of the life-history strategies present in tardigrades. This new species is differentiated from all other species of the genus by the presence of granules (~1 µm in diameter) on the dorsal cuticle of the last two body segments, two large bulges (gibbosities) on the hindlegs and long, conical egg processes. The species exhibits sexual dimorphism in body length, with females being longer than males of the same age. The mean lifespan of specimens was 86 days, with a maximum of 150 days. The mean age at first oviposition was 19.8 days and the mean egg hatching time 15.4 days. The life-cycle traits correspond to those collected for the only other two macrobiotid species with gonochoric amphimictic reproduction examined so far.

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