More sires may enhance offspring fitness in Northern Map Turtles (Graptemys geographica)

2013 ◽  
Vol 91 (8) ◽  
pp. 581-588 ◽  
Author(s):  
Nicola Banger ◽  
Gabriel Blouin-Demers ◽  
Grégory Bulté ◽  
Stephen C. Lougheed
Keyword(s):  
Sexual Selection ◽  
Reproductive Success ◽  
Hatching Success ◽  
Locomotor Performance ◽  
Conservative Estimate ◽  
Genetic Quality ◽  
Offspring Fitness ◽  
Sexual Selection Theory ◽  
Map Turtles ◽  
Graptemys Geographica

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.

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

2021 ◽  
pp. 1-12
Author(s):  
Janko Međedović
Keyword(s):  
Sexual Selection ◽  
Reproductive Success ◽  
Parental Investment ◽  
Reproductive Fitness ◽  
Human Populations ◽  
Number Of Children ◽  
Fitness Indicators ◽  
Number Of Sexual Partners ◽  
Sexual Selection Theory

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.

scholarly journals Sexual selection and hermaphroditic organisms: Testing theory

2013 ◽  
Vol 59 (4) ◽  
pp. 579-588 ◽  
Author(s):  
Janet L. Leonard
Keyword(s):  
Sexual Selection ◽  
Reproductive Success ◽  
Multiple Mating ◽  
The Other ◽  
Operational Sex Ratio ◽  
Sexual Role ◽  
Sexual Roles ◽  
Sexual Selection Theory ◽  
Variance In Reproductive Success ◽  
Simultaneous Hermaphrodites

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.

scholarly journals Darwin's bawdy: the popular, gendered and radical reception of the Descent of Man in the US, 1871–1910

BJHS Themes ◽  
2021 ◽  
pp. 1-17
Author(s):  
Kimberly A. Hamlin
Keyword(s):  
Sexual Selection ◽  
Selection Theory ◽  
Scientific Establishment ◽  
Scientific Institutions ◽  
The Us ◽  
Sexual Selection Theory ◽  
Descent Of Man

Abstract Most studies of the American reception of Darwin have focused on the Origin. The Descent of Man, however, was even more widely read and discussed, especially by those outside the emerging scientific establishment. This essay maps the varied, popular and radical responses to the Descent and suggests that these unauthorized readers helped shape the formation of American scientific institutions (by encouraging scientists to close ranks), as well as ordinary Americans’ perceptions of gender and sex. I argue that the radical – freethinkers, socialists and feminists – embrace of sexual selection theory provides one explanation for naturalists’ scepticism of the theory.

scholarly journals An introduction to genetic quality in the context of sexual selection

Genetica ◽  
2008 ◽  
Vol 134 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Trevor E. Pitcher ◽  
Herman L. Mays
Keyword(s):  
Sexual Selection ◽  
Genetic Quality
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