scholarly journals Ageing via perception costs of reproduction magnifies sexual selection

2018 ◽  
Vol 285 (1892) ◽  
pp. 20182136 ◽  
Author(s):  
Roberto García-Roa ◽  
Manuel Serra ◽  
Pau Carazo
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Sex Pheromones ◽  
Male Reproductive Success ◽  
Selection Intensity ◽  
Costs Of Reproduction ◽  
Short Term ◽  
Male Mortality ◽  
Wide Range ◽  
Reproductive Ageing

Understanding what factors modulate sexual selection intensity is crucial to a wide variety of evolutionary processes. Recent studies show that perception of sex pheromones can severely impact male mortality when it is not followed by mating (perception costs of reproduction). Here, we examine the idea that this may magnify sexual selection by further decreasing the fitness of males with inherently low mating success, hence increasing the opportunity for sexual selection. We use mathematical modelling to show that even modest mortality perception costs can significantly increase variability in male reproductive success under a wide range of demographic conditions. We then conduct a series of assays suggesting that, in Drosophila melanogaster , failure to reproduce early in life may, via perception costs of reproduction, significantly reduces the subsequent fitness of males ( ca 25%), due mostly to increased reproductive ageing. Altogether, our results strongly suggest that perception costs of reproduction can magnify sexual selection in a biologically significant way. Finally, we estimate that around 29% of available studies quantify sexual selection based on short-term fitness estimates that may fail to capture these effects (if they were present in their subject species), and suggest addressing the existence and impact of perception costs of reproduction across taxa should thus be a priority.

scholarly journals Genetic trade-offs between male reproductive traits in Drosophila melanogaster

2018 ◽  
Vol 14 (10) ◽  
pp. 20180474 ◽  
Author(s):  
David C. S. Filice ◽  
Tristan A. F. Long
Keyword(s):  
Drosophila Melanogaster ◽  
Reproductive Success ◽  
Selection Pressure ◽  
Reproductive Traits ◽  
Male Reproductive Success ◽  
Short Term ◽  
Trade Offs ◽  
Sexual Traits ◽  
Stimulation Of

In Drosophila melanogaster , males engage in both extensive pre- and post-copulatory competition for the opportunity to mate with females and subsequently sire offspring. The selection pressure for increased male reproductive success has resulted in the evolution of a wide diversity of sexual traits. However, despite strong selection, individuals often exhibit considerable phenotypic variation in the expression of these traits, and it is unclear if any of this variation is owing to underlying genetic trade-offs. Here, using hemiclonal flies, we examine how male reproductive success covaries with their ability to induce long-term stimulation of oogenesis and oviposition in their mates, and how this relationship may change over time. We found that males from hemiclone lines with phenotypes that were more successful in a short-term reproductive ‘scramble’ environment were less effective at stimulating long-term fecundity in females. Furthermore, we observed that males from hemiclone lines which showed the most improvement over a longer reproductive interaction period also tended to stimulate higher long-term fecundity in females. Together, these results indicate the presence of genetic trade-offs between different male reproductive traits and offer insights into the maintenance of their variation.

Effects of Atovaquone on the Ultrastructural Morphology of Pneumocystis Carinii

1997 ◽  
Vol 3 (S2) ◽  
pp. 81-82
Author(s):  
M.P. Goheen ◽  
M.S. Bartlett ◽  
M.M. Shaw ◽  
S.R. Meshnick ◽  
J.W. Smith
Keyword(s):  
Adverse Reactions ◽  
Pneumocystis Carinii ◽  
Spinner Flask ◽  
Short Term ◽  
Human Embryonic Lung ◽  
Transmission Electron ◽  
Significant Incidence ◽  
Wide Range ◽  
Acquired Immunodeficiency ◽  
Immunodeficiency Syndrome

Pneumocystis carinii pneumonia (PCP) occurs at some time in most patients with acquired immunodeficiency syndrome (AIDS). Trimethoprim/sulfamethoxazole or pentamidine isothionate are the traditional modes of therapy for treatment and prophylaxis of PCP. Unfortunately these drugs are associated with a significant incidence of adverse side effects particularly in patients with AIDS. Toxicity and a growing concern that P. carinii strains are becoming resistant to these compounds is providing the impetus for the search for additional drugs to combat P. carinii. Atovaquone, developed as an antimalarial agent, has activity against a wide range of other organisms, including Toxoplasma sp. and P. carinii, with a lower incidence of adverse reactions during clinical trials. Atovaquone inhibits mitochondrial respiration in P. falciparum and P. carinii. In this study transmission electron microscopy (TEM) was used to observe the effects of atovaquone on P. carinii organisms in short term spinner flask culture.Spinner flask cultures of human embryonic lung cells were inoculated with P. carinii from infected rat lung.

Does allometry of a sexually selected ornamental trait vary with sexual selection intensity? A multi-species test in damselflies

2014 ◽  
Vol 39 (3) ◽  
pp. 399-403 ◽  
Author(s):  
DAVID OUTOMURO ◽  
ADOLFO CORDERO RIVERA ◽  
ANGELA NAVA-BOLAÑOS ◽  
ALEX CÓRDOBA-AGUILAR
Keyword(s):  
Sexual Selection ◽  
Selection Intensity

scholarly journals The physical environment mediates male harm and its effect on selection in females

2017 ◽  
Vol 284 (1858) ◽  
pp. 20170424 ◽  
Author(s):  
Li Yun ◽  
Patrick J. Chen ◽  
Amardeep Singh ◽  
Aneil F. Agrawal ◽  
Howard D. Rundle
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Physical Environment ◽  
Selective Advantage ◽  
Laboratory Studies ◽  
Male Choice ◽  
Female Fitness ◽  
High Quality ◽  
Evolutionary Consequences ◽  
Natural And Sexual Selection

Recent experiments indicate that male preferential harassment of high-quality females reduces the variance in female fitness, thereby weakening natural selection through females and hampering adaptation and purging. We propose that this phenomenon, which results from a combination of male choice and male-induced harm, should be mediated by the physical environment in which intersexual interactions occur. Using Drosophila melanogaster , we examined intersexual interactions in small and simple (standard fly vials) versus slightly more realistic (small cages with spatial structure) environments. We show that in these more realistic environments, sexual interactions are less frequent, are no longer biased towards high-quality females, and that overall male harm is reduced. Next, we examine the selective advantage of high- over low-quality females while manipulating the opportunity for male choice. Male choice weakens the viability advantage of high-quality females in the simple environment, consistent with previous work, but strengthens selection on females in the more realistic environment. Laboratory studies in simple environments have strongly shaped our understanding of sexual conflict but may provide biased insight. Our results suggest that the physical environment plays a key role in the evolutionary consequences of sexual interactions and ultimately the alignment of natural and sexual selection.

scholarly journals Absence of reproduction-immunity trade-off in male Drosophila melanogaster evolving under differential sexual selection

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Zeeshan Ali Syed ◽  
Vanika Gupta ◽  
Manas Geeta Arun ◽  
Aatashi Dhiman ◽  
Bodhisatta Nandy ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Trade Off

scholarly journals Sex ratio effects on reproductive strategies in humans

2015 ◽  
Vol 2 (1) ◽  
pp. 140402 ◽  
Author(s):  
Ryan Schacht ◽  
Monique Borgerhoff Mulder
Keyword(s):  
Sexual Selection ◽  
Sex Ratio ◽  
Ethnic Group ◽  
Reproductive Strategies ◽  
Situational Factors ◽  
Male Mating ◽  
Mating Effort ◽  
Short Term ◽  
Adult Sex Ratio ◽  
Using Data

Characterizations of coy females and ardent males are rooted in models of sexual selection that are increasingly outdated. Evolutionary feedbacks can strongly influence the sex roles and subsequent patterns of sex differentiated investment in mating effort, with a key component being the adult sex ratio (ASR). Using data from eight Makushi communities of southern Guyana, characterized by varying ASRs contingent on migration, we show that even within a single ethnic group, male mating effort varies in predictable ways with the ASR. At male-biased sex ratios, men's and women's investment in mating effort are indistinguishable; only when men are in the minority are they more inclined towards short-term, low investment relationships than women. Our results support the behavioural ecological tenet that reproductive strategies are predictable and contingent on varying situational factors.

scholarly journals Family and childcare support public expenditures and short-term fertility dynamics

2013 ◽  
Vol 60 (3) ◽  
pp. 347-364 ◽  
Author(s):  
Cosmin Enache
Keyword(s):  
Birth Rate ◽  
Crude Birth Rate ◽  
Low Fertility ◽  
Alternative Methods ◽  
Public Expenditures ◽  
Short Term ◽  
Wide Range ◽  
Policy Measures ◽  
Support Policy ◽  
Cash Benefits

In a period of very low fertility, effective family and childcare support policy measures are needed. From a wide range of instruments available to government intervention, we focus on public expenditures effects on short-term fertility. Using a sample of 28 European countries in a panel framework, we found that there is a small positive elasticity of crude birth rate to cash benefits related to childbirth and childrearing provided through social security system. Different public services provided to ease the burden of parents and all other benefits in kind, means or non-means tested, are found to be insignificant. These results are robust to alternative methods of estimation. Controlling for country heterogeneity by religion and by culture, some particularly interesting differences in birth rate determinants were highlighted as well.

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