Long-term mating positively predicts both reproductive fitness and parental investment

2021 ◽  
pp. 1-12
Author(s):  
Janko Međedović

Abstract Empirical data on the relations between mating and reproductive success are rare for humans, especially for industrial and post-industrial populations. Existing data show that mating (and especially long-term mating) can be beneficial for fitness, especially that of males. This finding is in line with the hypothesis of sexual selection operating in human populations. The present research expands on previous studies by: 1) analysing additional fitness indicators, including having children with different partners; 2) including parental investment in the analysis as another important marker of sexual selection; 3) analysing several mediators between mating, reproductive fitness and parental investment, i.e. age of first and last reproduction and desired number of children. The data were obtained in 2019 from a sample of parents living in Serbia (N=497). The findings showed that long-term mating (duration of longest partner relationship) was positively related to parental investment and number of offspring and grand-offspring. Furthermore, the link between long-term mating and reproductive success was completely mediated by the age of first reproduction and desired number of children. Short-term mating (number of sexual partners) was marginally positively related to the number of children participants had with different partners and negatively related to parental investment. No sex differences in the link between mating, fitness and parental investment were detected. In general, the signatures of sexual selection were weak in the present data, but those that were detected were in line with sexual selection theory. The present findings provide a deeper insight into the adaptive function of mating and also the mechanism of how mating is beneficial for fitness.

2017 ◽  
Vol 15 (2) ◽  
pp. 147470491770693 ◽  
Author(s):  
Janko Međedović

The evolutionary status of intelligence is not clear: It is positively related to various indicators of fitness but negatively to reproductive success as the most important fitness marker. In the present research, we explored the links between intelligence and three fitness indicators: number of children (short-term reproductive success), number of grandchildren (long-term reproductive success), and age at first birth. Participants were individuals in a postreproductive stage ( N = 191; mean age = 66.5 years). Intelligence had a positive correlation with short-term reproductive success and age at first birth but a negative correlation with long-term reproductive success. Participants’ education turned out to be a significant mediator of the link between intelligence and criterion measures. The results showed that intelligence can elevate short-term reproductive success. Furthermore, individuals with higher intellectual abilities tended to delay reproduction, which negatively affected their long-term reproductive success. Education was revealed as a very important resource which affects the link between cognitive abilities and fitness, thus proving its evolutionary role in contemporary populations.


2020 ◽  
Author(s):  
Janko Mileta Međedović

Mating patterns are crucial for understanding selection regimes in current populations and highly implicative for sexual selection and life history theory. However, empirical data on the relations between mating and fitness-related outcomes in contemporary humans are lacking. In the present research we examined the sexual selection on mating (with an emphasis on Bateman’s third parameter – the association between mating and reproductive success) and life history dynamics of mating by examining the relations between mating patterns and a comprehensive set of variables which determine human reproductive ecology. We conducted two studies (Study 1: N=398, Mage=31.03; Study 2: N=996, Mage=40.81, the sample was representative for participants’ sex, age, region, and settlement size). The findings from these studies were mutually congruent and complementary. In general, the data suggested that short-term mating was unrelated or even negatively related to reproductive success. Conversely, long-term mating was positively associated with reproductive success and there were indices that the beneficial role of long-term mating is more pronounced in males, which is in accordance with Bateman’s third principle. Observed age of first reproduction fully mediated the link between long-term mating and number of children but only in male participants. There were no clear indications of the position of the mating patterns in human life history trajectories; however, the obtained data suggested that long-term mating has some characteristics of fast life history dynamics. Findings are implicative for sexual selection and life history theory in humans.


2019 ◽  
Vol 17 (3) ◽  
pp. 147470491985976 ◽  
Author(s):  
Ali Kasaeian ◽  
Corina Weidenauer ◽  
Martin Hautzinger ◽  
Christoph Randler

Following previous studies, chronotype was related to sexual attitudes and behavior. Evening people tend to be more promiscuous and follow short-term mating strategies and extra-pair matings (EPM), which might lead to a higher reproductive success. In this study, one aim was to assess reproductive success directly by asking for children, and, second, to obtain a higher sample size for the analysis of sexual behavior and chronotype than in previous studies. N = 1,843 heterosexual persons (551 men, 1,288 women, 4 without data) responded to our online survey. Five hundred fifty-nine persons were single and 1,281 in a relationship; 203 reported having children (1.9 ± 0.81). Age was positively related and age at first intercourse was negatively related to the number of children. People being later chronotypes had fewer children, and shorter sleep duration was linked with more children. Extroversion was correlated with number of children, as was the long-term relationship orientation. Sociosexual orientation and EPM were unrelated to number of children. Age at first intercourse was earlier in evening people, and unrestricted sociosexuality was higher in late chronotypes. Morning orientation correlated with long-term relationship orientation and eveningness with short-term relationship orientation. Number of sexual partners was lower in morning people. Men were more evening oriented, later chronotypes, and slept shorter. There were no differences in sociosexual behavior, but men were less restricted in attitude and desire. Men scored higher on short-term relationship orientation and women higher on long-term relationship orientation. This study confirmed previous results about chronotype and sexual behavior but provided the first evidence that morningness was related to higher reproductive success.


2021 ◽  
Vol 19 (4) ◽  
pp. 147470492110571
Author(s):  
Janko Međedović

Mating patterns are crucial for understanding selection regimes in current populations and highly implicative for sexual selection and life history theory. However, empirical data on the relations between mating and reproductive outcomes in contemporary humans are lacking. In the present research we examined the sexual selection on mating (with an emphasis on Bateman's third parameter – the association between mating and reproductive success) and life history dynamics of mating by examining the relations between mating patterns and a comprehensive set of variables which determine human reproductive ecology. We conducted two studies (Study 1: N = 398, Study 2: N = 996, the sample was representative for participants’ sex, age, region, and settlement size). The findings from these studies were mutually congruent and complementary. In general, the data suggested that short-term mating was unrelated or even negatively related to reproductive success. Conversely, long-term mating was positively associated with reproductive success (number of children in Study 1; number of children and grandchildren in Study 2) and there were indices that the beneficial role of long-term mating is more pronounced in males, which is in accordance with Bateman's third principle. Observed age of first reproduction mediated the link between long-term mating and number of children but only in male participants (Study 2). There were no clear indications of the position of the mating patterns in human life history trajectories; however, the obtained data suggested that long-term mating has some characteristics of fast life history dynamics. Findings are implicative for sexual selection and life history theory in humans.


2013 ◽  
Vol 91 (8) ◽  
pp. 581-588 ◽  
Author(s):  
Nicola Banger ◽  
Gabriel Blouin-Demers ◽  
Grégory Bulté ◽  
Stephen C. Lougheed

Sexual selection theory predicts that males should be promiscuous to maximize their reproductive success, while females should be choosy. Yet females of many taxa often produce progeny sired by multiple males, indicating that promiscuity can be important for the reproductive success of females. Promiscuity may enhance the fitness of females if it increases the genetic quality, or the genetic variety, and thus the viability of their offspring. We quantified the number of sires per clutch in a population of Northern Map Turtles (Graptemys geographica (LeSueur, 1817)) in Lake Opinicon, Ontario, Canada, and tested whether the number of sires affects several metrics of viability in hatchlings. Based on the most conservative estimate, at least 71% of clutches in this population are sired by multiple males, but there was no evidence that larger clutches are sired by more males. Clutches sired by more males had higher hatching success and survival, but the differences were not statistically significant. We did not find any effect of the number of sires on hatchling morphology or locomotor performance. Collectively, our results partially support the hypothesis that promiscuity can increase the reproductive success of female Northern Map Turtles.


Author(s):  
Yael Sela ◽  
Nicole Barbaro

Religion motivates, exacerbates, and even justifies violence. This chapter argues that religious beliefs regarding violence—particularly those of monotheistic, Abrahamic faiths—are shaped by evolved psychological mechanisms. Further, it argues that religiously motivated violence is most likely to occur in evolutionarily relevant contexts. Guided by sexual selection theory and parental-investment theory, it first provides an overview of human sexual selection from an evolutionary perspective. It discusses how and why an evolutionary perspective—and principles of sexual selection and parental investment in particular—may provide a richer understanding of religiously motivated violence. Next follows an overview of research addressing several types of religiously motivated violence such as mate guarding and controlling behaviors, wife beating and uxoricide, honor killing, child abuse and filicide, male and female genital mutilation, war, and terrorism. Finally, it highlights the parallels between religiously motivated violence and evolved psychological mechanisms for violence, concluding with suggestions for future research.


2013 ◽  
Vol 59 (4) ◽  
pp. 579-588 ◽  
Author(s):  
Janet L. Leonard

Abstract Sexual selection is widespread if not ubiquitous in hermaphroditic organisms. Although many phenomena that have been described as sexual selection in gonochores, (e.g. harem polygamy, multiple mating, elaborate courtship, even secondary sexual characters) can be found in some hermaphrodites, what is more interesting is the ways in which sexual selection in hermaphrodites may differ from dioecious taxa. In hermaphrodites, an individual’s mating success includes its success from both sexual roles. Secondly, in many simultaneously hermaphroditic taxa there is strong evidence of sexual selection and yet the operational sex ratio is 1:1, by definition. Many simultaneous hermaphrodites have elaborate courtship and genital anatomy, suggesting sexual selection plays an important role in reproductive success. Sperm competition and cryptic female choice mean that the number of mates acquired is not necessarily a predictor of reproductive success. Even in simultaneous hermaphrodites with reciprocal mating, variance in reproductive success through the male role and through the female role may differ in a population. Moreover hermaphrodites may choose to emphasize one sexual role over the other. Data suggest that the preferred role varies in hermaphrodites, which creates an opportunity to test fundamental predictions and assumptions of sexual selection theory. Hermaphrodites may vary their emphasis on one sexual role over the other either developmentally or behaviorally in response to environmental or social parameters. How they use this capability in acquiring more or higher quality mates still requires study.


2016 ◽  
Vol 35 (6) ◽  
pp. 645-666 ◽  
Author(s):  
Jinguang Zhang

Previous research found that speakers with more attractive voices receive more favorable evaluations (aka the vocal attractiveness stereotype). But sexual selection theory predicts that, to the extent that men perceive women with higher pitched voices as more attractive, women will be more hostile toward those women because they make more threatening mate rivals. Supporting this hypothesis, Study 1 ( N = 102) showed that female participants higher in trait dominance displayed heightened aggressive cognition after being primed with a romantic (but not a control) feeling and listening to a higher- but not lower-than-average female voice. Study 2 ( N = 111) showed that this heightened aggressive cognition was activated by a long-term but not a short-term mating motive. These findings supported sexual selection theory, challenged the vocal attractiveness stereotype, and suggested a mechanism that helps maintain the honesty of female voice pitch as a mate attraction signal.


2020 ◽  
Author(s):  
Eugene J. Gardner ◽  
Matthew D. C. Neville ◽  
Kaitlin E. Samocha ◽  
Kieron Barclay ◽  
Martin Kolk ◽  
...  

SummaryGenome-wide sequencing of human populations has revealed substantial variation among genes in the intensity of purifying selection acting on damaging genetic variants. While genes under the strongest selective constraint are highly enriched for Mendelian disorders, most of these genes are not associated with disease and therefore the nature of the selection acting on them is not known. Here we show that genetic variants that damage these genes reduce reproductive success substantially in males but much less so in females. We present evidence that this reduction is mediated primarily by cognitive and behavioural traits, which renders male carriers of such variants less likely to find mating partners. These findings represent strong genetic evidence that sexual selection mediated through female mate choice is shaping the gene pool of contemporary human populations. Furthermore, these results suggest that sexual selection accounts for 21% of purifying selection against heterozygous variants that ablate protein-coding genes.


Author(s):  
Gonzalo Alarcos ◽  
Jaime Madrigal-González ◽  
Miguel Lizana ◽  
Fabio Flechoso

There are many biometric differences between the males and females of the European pond turtle (Emys orbicularis) as regards their size, colouring, the shape of the plastron, tail, etc. The males use their claws to grasp the female during copulation and hence sexual selection should favour the males that have larger claws, which allow them to grasp the female better. Here, we address this type of sexual dimorphism in a comparative analysis of indices obtained from claw length, the length of the carapace and the locality where individuals were sampled. The results show that the curvature of the claws differs between the two sexes, being longer in males and increasing with age, size, and hence, the state of sexual maturity, than in females. Greater claw length could confer advantages for males when grasping the carapace of females, and hence, improve their reproductive fitness. Importance in the reproductive success that might have this feature in males could originate future studies that will relate the shape, thickness, length and other measures of the claws in males with their reproductive success in different populations, genetic variety, and most importantly, viability of populations. 


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