Parental Influence and Sexual Selection

2021 ◽  
pp. 154-170
Author(s):  
Menelaos Apostolou
Keyword(s):  
Sexual Selection ◽  
Opportunity Cost ◽  
Parental Influence ◽  
Genetic Relatedness ◽  
Parental Choice ◽  
Direct Control ◽  
Arranged Marriage ◽  
Human Species ◽  
Trade Offs ◽  
Selection Force

This chapter addresses how the genetic relatedness between parents and their children results in the two parties having converging as well as diverging interests. In the domain of mating, these interests, along with other factors such as the trade-offs inherent in mating, give rise to an opportunity cost of free mate choice: Parents have much to lose if they allow their children to exercise choice freely. This opportunity cost provides a strong incentive to parents to influence their children’s mate choices. In preindustrial societies, parents manage to exercise direct control, which is predominantly manifested in the institution of arranged marriage. In postindustrial societies, parents exercise influence indirectly through manipulation. Ultimately, parental influence over mating gives rise to a sexual selection force, namely parental choice, which may be unique to the human species.

scholarly journals Evolution of body size in Galapagos marine iguanas

2005 ◽  
Vol 272 (1576) ◽  
pp. 1985-1993 ◽  
Author(s):  
Martin Wikelski
Keyword(s):  
Sexual Selection ◽  
Body Size ◽  
Complex Traits ◽  
Genetic Relatedness ◽  
Food Competition ◽  
Future Research ◽  
Trade Offs ◽  
Body Sizes ◽  
Genetic Mechanisms ◽  
Marine Iguanas

Body size is one of the most important traits of organisms and allows predictions of an individual's morphology, physiology, behaviour and life history. However, explaining the evolution of complex traits such as body size is difficult because a plethora of other traits influence body size. Here I review what we know about the evolution of body size in a group of island reptiles and try to generalize about the mechanisms that shape body size. Galapagos marine iguanas occupy all 13 larger islands in this Pacific archipelago and have maximum island body weights between 900 and 12 000 g. The distribution of body sizes does not match mitochondrial clades, indicating that body size evolves independently of genetic relatedness. Marine iguanas lack intra- and inter-specific food competition and predators are not size-specific, discounting these factors as selective agents influencing body size. Instead I hypothesize that body size reflects the trade-offs between sexual and natural selection. We found that sexual selection continuously favours larger body sizes. Large males establish display territories and some gain over-proportional reproductive success in the iguanas' mating aggregations. Females select males based on size and activity and are thus responsible for the observed mating skew. However, large individuals are strongly selected against during El Niño-related famines when dietary algae disappear from the intertidal foraging areas. We showed that differences in algae sward (‘pasture’) heights and thermal constraints on large size are causally responsible for differences in maximum body size among populations. I hypothesize that body size in many animal species reflects a trade-off between foraging constraints and sexual selection and suggest that future research could focus on physiological and genetic mechanisms determining body size in wild animals. Furthermore, evolutionary stable body size distributions within populations should be analysed to better understand selection pressures on individual body size.

Are parental care trade-offs in shorebirds driven by parental investment or sexual selection?

2009 ◽  
Vol 22 (4) ◽  
pp. 672-682 ◽  
Author(s):  
V. A. OLSON ◽  
T. J. WEBB ◽  
R. P. FRECKLETON ◽  
T. SZÉKELY
Keyword(s):  
Sexual Selection ◽  
Parental Care ◽  
Parental Investment ◽  
Trade Offs

Post-Copulatory Sexual Selection

2021 ◽  
Author(s):  
Patricia L.R. Brennan ◽  
Dara N. Orbach
Keyword(s):  
Sexual Selection ◽  
Sperm Competition ◽  
Female Choice ◽  
Reproductive Tract ◽  
Seminal Fluid ◽  
Fertilization Success ◽  
Female Reproductive Tract ◽  
Cryptic Female Choice ◽  
Trade Offs ◽  
Morphological Criteria

The field of post-copulatory sexual selection investigates how female and male adaptations have evolved to influence the fertilization of eggs while optimizing fitness during and after copulation, when females mate with multiple males. When females are polyandrous (one female mates with multiple males), they may optimize their mating rate and control the outcome of mating interactions to acquire direct and indirect benefits. Polyandry may also favor the evolution of male traits that offer an advantage in post-copulatory male-male sperm competition. Sperm competition occurs when the sperm, seminal fluid, and/or genitalia of one male directly impacts the outcome of fertilization success of a rival male. When a female mates with multiple males, she may use information from a number of traits to choose who will sire her offspring. This cryptic female choice (CFC) to bias paternity can be based on behavioral, physiological, and morphological criteria (e.g., copulatory courtship, volume and/or composition of seminal fluid, shape of grasping appendages). Because male fitness interests are rarely perfectly aligned with female fitness interests, sexual conflict over mating and fertilization commonly occur during copulatory and post-copulatory interactions. Post-copulatory interactions inherently involve close associations between female and male reproductive characteristics, which in many species potentially include sperm storage and sperm movement inside the female reproductive tract, and highlight the intricate coevolution between the sexes. This coevolution is also common in genital morphology. The great diversity of genitalia among species is attributed to sexual selection. The evolution of genital attributes that allow females to maintain reproductive autonomy over paternity via cryptic female choice or that prevent male manipulation and sexual control via sexually antagonistic coevolution have been well documented. Additionally, cases where genitalia evolve through intrasexual competition are well known. Another important area of study in post-copulatory sexual selection is the examination of trade-offs between investments in pre-copulatory and post-copulatory traits, since organisms have limited energetic resources to allocate to reproduction, and securing both mating and fertilization is essential for reproductive success.

scholarly journals Temperature as a modulator of sexual selection

2018 ◽  
Author(s):  
Roberto García-Roa ◽  
Francisco Garcia-Gonzalez ◽  
Daniel W.A. Noble ◽  
Pau Carazo
Keyword(s):  
Global Warming ◽  
Sexual Selection ◽  
Thermal Environment ◽  
Abiotic Factors ◽  
Meta Analysis ◽  
Population Viability ◽  
Order Effects ◽  
Secondary Sexual Traits ◽  
Trade Offs ◽  
Wide Range

A central question in ecology and evolution is to understand why sexual selection varies so much in strength across taxa, and it has long been known that ecological factors are crucial to this respect. Temperature is a particularly critical abiotic ecological factor that can drastically modulate a wide range of physiological, morphological and behavioural traits, impacting individuals and populations at a global taxonomic scale. Furthermore, temperature exhibits substantial temporal variation (e.g. daily, seasonally and inter-seasonally), and hence for most species in the wild sexual selection will regularly unfold in a dynamic thermal environment. Unfortunately, studies have so far almost completely neglected the role of temperature as a modulator of sexual selection. Here, we outline the main pathways via which temperature can affect the intensity and form (i.e. mechanisms) of sexual selection, via: a) direct effects on secondary sexual traits and preferences (i.e. trait variance, opportunity for selection and trait-fitness covariance), and b) indirect effects on key mating parameters, sex-specific reproductive costs/benefits, trade-offs, demography and correlated abiotic factors. Building upon this framework, we show that, by focusing exclusively on the first order effects that environmental temperature has on traits linked with individual fitness and population viability, current global warming studies may be ignoring important eco-evolutionary feedbacks mediated by sexual selection. Finally, we tested the general prediction that temperature modulates sexual selection by conducting a meta-analysis of available studies experimentally manipulating temperature and reporting effects on the variance of male/female reproductive success and/or traits under sexual selection. Our results show a clear association between temperature and sexual selection measures in both sexes. In short, we suggest that studying the feedback between temperature and sexual selection processes can be vital to better understand variation in the strength of sexual selection in nature, and its consequences for population viability in response to environmental change (e.g. global warming).

scholarly journals The role of oxidative stress in postcopulatory selection

2020 ◽  
Vol 375 (1813) ◽  
pp. 20200065
Author(s):  
Christopher R. Friesen ◽  
Daniel W. A. Noble ◽  
Mats Olsson
Keyword(s):  
Oxidative Stress ◽  
Sexual Selection ◽  
Life History Theory ◽  
Primary Source ◽  
Research Area ◽  
Good Genes ◽  
Atp Production ◽  
Left Behind ◽  
Trade Offs ◽  
Postcopulatory Selection

Two decades ago, von Schantz et al . (von Schantz T, Bensch S, Grahn M, Hasselquist D, Wittzell H. 1999 Good genes, oxidative stress and condition-dependent sexual signals. Proc. R. Soc. B 266, 1–12. ( doi:10.1098/rspb.1999.0597 )) united oxidative stress (OS) biology with sexual selection and life-history theory. This set the scene for analysis of how evolutionary trade-offs may be mediated by the increase in reactive molecules resulting from metabolic processes at reproduction. Despite 30 years of research on OS effects on infertility in humans, one research area that has been left behind in this integration of evolution and OS biology is postcopulatory sexual selection—this integration is long overdue. We review the basic mechanisms in OS biology, why mitochondria are the primary source of ROS and ATP production during oxidative metabolism, and why sperm, and its performance, is uniquely susceptible to OS. We also review how postcopulatory processes select for antioxidation in seminal fluids to counter OS and the implications of the net outcome of these processes on sperm damage, sperm storage, and female and oocyte manipulation of sperm metabolism and repair of DNA to enhance offspring fitness. This article is part of the theme issue ‘Fifty years of sperm competition’.

scholarly journals Sex roles, parental care and offspring growth in two contrasting coucal species

2016 ◽  
Vol 3 (10) ◽  
pp. 160463 ◽  
Author(s):  
Wolfgang Goymann ◽  
Ignas Safari ◽  
Christina Muck ◽  
Ingrid Schwabl
Keyword(s):  
Sexual Selection ◽  
Parental Care ◽  
Sex Roles ◽  
Evolutionary Ecology ◽  
Recent Theory ◽  
Uniparental Care ◽  
Trade Offs ◽  
Offspring Growth ◽  
Adult Sex Ratio

The decision to provide parental care is often associated with trade-offs, because resources allocated to parental care typically cannot be invested in self-maintenance or mating. In most animals, females provide more parental care than males, but the reason for this pattern is still debated in evolutionary ecology. To better understand sex differences in parental care and its consequences, we need to study closely related species where the sexes differ in offspring care. We investigated parental care in relation to offspring growth in two closely related coucal species that fundamentally differ in sex roles and parental care, but live in the same food-rich habitat with a benign climate and have a similar breeding phenology. Incubation patterns differed and uniparental male black coucals fed their offspring two times more often than female and male white-browed coucals combined. Also, white-browed coucals had more ‘off-times’ than male black coucals, during which they perched and preened. However, these differences in parental care were not reflected in offspring growth, probably because white-browed coucals fed their nestlings a larger proportion of frogs than insects. A food-rich habitat with a benign climate may be a necessary, but—perhaps unsurprisingly—is not a sufficient factor for the evolution of uniparental care. In combination with previous results (Goymann et al . 2015 J. Evol. Biol . 28 , 1335–1353 ( doi:10.1111/jeb.12657 )), these data suggest that white-browed coucals may cooperate in parental care, because they lack opportunities to become polygamous rather than because both parents were needed to successfully raise all offspring. Our case study supports recent theory suggesting that permissive environmental conditions in combination with a particular life history may induce sexual selection in females. A positive feedback loop among sexual selection, body size and adult sex-ratio may then stabilize reversed sex roles in competition and parental care.

scholarly journals Conjoint Analysis of Deer Hunting

1990 ◽  
Vol 19 (2) ◽  
pp. 109-117 ◽  
Author(s):  
John Mackenzie
Keyword(s):  
Willingness To Pay ◽  
Travel Time ◽  
Conjoint Analysis ◽  
Opportunity Cost ◽  
Travel Cost ◽  
Cost Analyses ◽  
Deer Hunting ◽  
Hunting Success ◽  
Trade Offs ◽  
Recreational Demand

This paper develops a logit-based conjoint analysis of willingness to pay for individual attributes of deer-hunting trips. Since deer-hunting success is uncertain, willingness to pay for enhanced likelihood of bagging a deer, rather than for certain success, is evaluated. Implicit costs of recreational travel time are also evaluated from hypothetical trade-offs between travel time and trip expenditures. The valuation of travel time derived here appears to reflect more the opportunity cost of foregone hunting than the opportunity cost of foregone work. This implies that travel-cost analyses of recreational demand, which impute costs of recreational travel solely from wage data, can yield biased valuations of recreational amenities.

Equity–efficiency trade-offs in health technology assessment

2006 ◽  
Vol 22 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Alan H. Williams ◽  
Richard A. Cookson
Keyword(s):  
Cost Effectiveness ◽  
Health Technology Assessment ◽  
Technology Assessment ◽  
Opportunity Cost ◽  
Smoking Status ◽  
Health Technology ◽  
Primary Objective ◽  
Trade Offs ◽  
Vested Interests ◽  
Methodological Principles

Health technology assessment (HTA) currently focuses on efficiency, rather than equity, on the basis that its primary objective is to maximize population health. Yet a strict cost-effectiveness approach sometimes conflicts with important equity concerns, such as the reduction of socioeconomic health inequalities. Managing such equity–efficiency trade-offs on the basis of intuition is unsatisfactory in a democracy, as it arouses suspicions of special pleading and favoritism toward vested interests. Over the next few decades, therefore, decision making may progress through up to three further stages of development observed historically in other areas of resource allocation. Stage two involves case law, limited to principles distilled from precedent. Stage three involves codification, seeking to generalize these principles without specifying their relative weights. Finally, at stage four, quantitative trade-offs are incorporated into a formula. At stage four, deliberation centers on adjustments to the formula, which would then be applied impartially, transparently, and fair-mindedly to all future decisions. Methods already exist for valuing equity–efficiency trade-offs, based on established methodological principles for valuing trade-offs between different dimensions of health. Early findings indicate that the general public thinks that social class inequalities are more inequitable than those by smoking status, with inequalities between the sexes somewhere in between. Relative weights can be calculated from these data, although the data are not yet comprehensive enough to do this credibly for current policy purposes. In the mean time, the equity–efficiency trade-offs suggested by current decisions can be estimated using standard cost-effectiveness analysis. This is because every departure from a strict cost-effectiveness approach has an opportunity cost. The size of that opportunity cost is a test of how much weight a particular equity concern is deemed to merit.

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