scholarly journals Physiological demands and nutrient intake modulate a trade-off between dispersal and reproduction based on age and sex of field crickets

2021 ◽  
Vol 224 (7) ◽  
Author(s):  
Lisa A. Treidel ◽  
Rebecca M. Clark ◽  
Melissa T. Lopez ◽  
Caroline M. Williams

ABSTRACT Animals adjust resource acquisition throughout life to meet changing physiological demands of growth, reproduction, activity and somatic maintenance. Wing-polymorphic crickets invest in either dispersal or reproduction during early adulthood, providing a system in which to determine how variation in physiological demands, determined by sex and life history strategy, impact nutritional targets, plus the consequences of nutritionally imbalanced diets across life stages. We hypothesized that high demands of biosynthesis (especially oogenesis in females) drive elevated resource acquisition requirements and confer vulnerability to imbalanced diets. Nutrient targets and allocation into key tissues associated with life history investments were determined for juvenile and adult male and female field crickets (Gryllus lineaticeps) when given a choice between two calorically equivalent but nutritionally imbalanced (protein- or carbohydrate-biased) artificial diets, or when restricted to one imbalanced diet. Flight muscle synthesis drove elevated general caloric requirements for juveniles investing in dispersal, but flight muscle quality was robust to imbalanced diets. Testes synthesis was not costly, and life history investments by males were insensitive to diet composition. In contrast, costs of ovarian synthesis drove elevated caloric and protein requirements for adult females. When constrained to a carbohydrate-biased diet, ovary synthesis was reduced in reproductive morph females, eliminating their advantage in early life fecundity over the dispersal morph. Our findings demonstrate that nutrient acquisition modulates dispersal–reproduction trade-offs in an age- and sex-specific manner. Declines in food quality will thus disproportionately affect specific cohorts, potentially driving demographic shifts and altering patterns of life history evolution.

2017 ◽  
Vol 284 (1864) ◽  
pp. 20171567 ◽  
Author(s):  
Francesca Santostefano ◽  
Alastair J. Wilson ◽  
Petri T. Niemelä ◽  
Niels J. Dingemanse

The pace-of-life syndrome (POLS) hypothesis predicts associations between life history and ‘risky’ behaviours. Individuals with ‘fast’ lifestyles should develop faster, reproduce earlier, exhibit more risk-prone behaviours, and die sooner than those with ‘slow’ lifestyles. While support for POLS has been equivocal to date, studies have relied on individual-level (phenotypic) patterns in which genetic trade-offs may be masked by environmental effects on phenotypes. We estimated genetic correlations between life history (development, lifespan, size) and risky behaviours (exploration, aggression) in a pedigreed population of Mediterranean field crickets ( Gryllus bimaculatus ). Path analyses showed that behaviours mediated some genetic relationships between life history traits, though not those involved in trade-offs. Thus, while specific predictions of POLS theory were not supported, genetic integration of behaviour and life history was present. This implies a major role for risky behaviours in life history evolution.


2017 ◽  
Author(s):  
József Garay ◽  
Villő Csiszár ◽  
Tamás F. Móri ◽  
András Szilágyi ◽  
Zoltán Varga ◽  
...  

AbstractParent-offspring communication remains an unresolved challenge for biologist. The difficulty of the challenge comes from the fact that it is a multifaceted problem with connections to life-history evolution, parent-offspring conflict, kin selection and signalling. Previous efforts mainly focused on modelling resource allocation at the expense of the dynamic interaction during a reproductive season. Here we present a two-stage model of begging where the first stage models the interaction between nestlings and parents within a nest and the second stage models the life-history trade-offs. We show in an asexual population that honest begging results in decreased variance of collected food between siblings, which leads to mean number of surviving offspring. Thus, honest begging can be seen as a special bet-hedging against informational uncertainty, which not just decreases the variance of fitness but also increases the arithmetic mean.Author SummaryParent-offspring communication is a fascinating problem that captures the attention of scientist and layman alike. Parent-offspring interaction is the first interaction with non-self in the life of most young birds and mammals. The future life success of such young animals crucially depends on how successful they are in interacting and communicating with their parents. This communication has different functions: it is important for the offspring to solicit food from the parent and it is important for the parent to be informed about the state (hunger level) of the offspring. There is an optimization problem on top of this level: the parent has to ‘decide’ what part of the available resources should be allocated to the offspring and what part should she keep for herself. Here we show in a probabilistic model that the honest phenotype -where offspring beg only if they are hungry-has a greater growth rate than a selfish type - which begs regardless of its hunger level. This result holds in asexual populations; here honesty serves as a reduction uncertainty for the parents. The improved decision making of the parents -in turn-increases the survival of the offspring as well.


2019 ◽  
Author(s):  
Gretchen F. Wagner ◽  
Emeline Mourocq ◽  
Michael Griesser

Biparental care systems are a valuable model to examine conflict, cooperation, and coordination between unrelated individuals, as the product of the interactions between the parents influences the fitness of both individuals. A common experimental technique for testing coordinated responses to changes in the costs of parental care is to temporarily handicap one parent, inducing a higher cost of providing care. However, dissimilarity in experimental designs of these studies has hindered interspecific comparisons of the patterns of cost distribution between parents and offspring. Here we apply a comparative experimental approach by handicapping a parent at nests of five bird species using the same experimental treatment. In some species, a decrease in care by a handicapped parent was compensated by its partner, while in others the increased costs of care were shunted to the offspring. Parental responses to an increased cost of care primarily depended on the total duration of care that offspring require. However, life history pace (i.e., adult survival and fecundity) did not influence parental decisions when faced with a higher cost of caring. Our study highlights that a greater attention to intergenerational trade-offs is warranted, particularly in species with a large burden of parental care. Moreover, we demonstrate that parental care decisions may be weighed more against physiological workload constraints than against future prospects of reproduction, supporting evidence that avian species may devote comparable amounts of energy into survival, regardless of life history strategy.


2007 ◽  
Vol 363 (1490) ◽  
pp. 375-398 ◽  
Author(s):  
John R Speakman

Life-history trade-offs between components of fitness arise because reproduction entails both gains and costs. Costs of reproduction can be divided into ecological and physiological costs. The latter have been rarely studied yet are probably a dominant component of the effect. A deeper understanding of life-history evolution will only come about once these physiological costs are better understood. Physiological costs may be direct or indirect. Direct costs include the energy and nutrient demands of the reproductive event, and the morphological changes that are necessary to facilitate achieving these demands. Indirect costs may be optional ‘compensatory costs’ whereby the animal chooses to reduce investment in some other aspect of its physiology to maximize the input of resource to reproduction. Such costs may be distinguished from consequential costs that are an inescapable consequence of the reproductive event. In small mammals, the direct costs of reproduction involve increased energy, protein and calcium demands during pregnancy, but most particularly during lactation. Organ remodelling is necessary to achieve the high demands of lactation and involves growth of the alimentary tract and associated organs such as the liver and pancreas. Compensatory indirect costs include reductions in thermogenesis, immune function and physical activity. Obligatory consequential costs include hyperthermia, bone loss, disruption of sleep patterns and oxidative stress. This is unlikely to be a complete list. Our knowledge of these physiological costs is currently at best described as rudimentary. For some, we do not even know whether they are compensatory or obligatory. For almost all of them, we have no idea of exact mechanisms or how these costs translate into fitness trade-offs.


2015 ◽  
Vol 8 (7) ◽  
pp. 635-649 ◽  
Author(s):  
Emilie Snell‐Rood ◽  
Rickey Cothran ◽  
Anne Espeset ◽  
Punidan Jeyasingh ◽  
Sarah Hobbie ◽  
...  

1989 ◽  
Vol 3 (3) ◽  
pp. 259 ◽  
Author(s):  
S. C. Stearns

1990 ◽  
Vol 68 (1) ◽  
pp. 44-48 ◽  
Author(s):  
Larry D. Marshall

Daily egg production of the moth Parapediasia teterrella declined over the life-span of the female but egg size remained constant. The absence of water resulted in lower fecundity and early mortality. Egg size and lifetime fecundity showed considerable inter-individual variation and large females produced more and larger eggs than their smaller counterparts. Large females expended greater reproductive effort than small females. Hatching success was negatively related to egg size. In spite of this, large females laying large eggs had higher fitness than small females. I postulate that multiple reproductive strategies within a species, resulting from differences in reproductive effort expended, may explain why expected trade-offs in reproductive parameters (e.g., egg size versus egg number) were not found in this species. Furthermore, I argue that the prevalent interpretation of life-history evolution (that body size is the important determining parameter of life-history parameters) may reflect correlation of body size with reproductive effort, and reproductive effort may be more important in determining the nature of trade-offs between reproductive parameters.


2009 ◽  
Vol 276 (1663) ◽  
pp. 1737-1745 ◽  
Author(s):  
Damian K. Dowling ◽  
Leigh W. Simmons

Evolutionary theory is firmly grounded on the existence of trade-offs between life-history traits, and recent interest has centred on the physiological mechanisms underlying such trade-offs. Several branches of evolutionary biology, particularly those focusing on ageing, immunological and sexual selection theory, have implicated reactive oxygen species (ROS) as profound evolutionary players. ROS are a highly reactive group of oxygen-containing molecules, generated as common by-products of vital oxidative enzyme complexes. Both animals and plants appear to intentionally harness ROS for use as molecular messengers to fulfil a wide range of essential biological processes. However, at high levels, ROS are known to exert very damaging effects through oxidative stress. For these reasons, ROS have been suggested to be important mediators of the cost of reproduction, and of trade-offs between metabolic rate and lifespan, and between immunity, sexual ornamentation and sperm quality. In this review, we integrate the above suggestions into one life-history framework, and review the evidence in support of the contention that ROS production will constitute a primary and universal constraint in life-history evolution.


2021 ◽  
pp. 59-74
Author(s):  
Jeffrey A. Hutchings

Predictions about life-history evolution are intellectually bereft without a consideration of trade-offs. Benefits derived from making one life-history ‘decision’ are made at a cost of not realizing potential benefits associated with alternative decisions. These trade-offs are the inevitable product of constraints, often driven by an individual’s differential allocation of fixed resources to reproduction versus survival or growth. These allocations prevent multiple positive outcomes from being simultaneously realized. Reproductive effort is the proportion of total energy or resources allocated to all elements of reproduction. Reproductive effort generates reproductive costs. Increases in current reproductive effort reduce future reproductive success by affecting survival, growth, and/or fecundity. The causal mechanisms of these costs can be energetic, ecological, behavioural, or genetic. Evidence for reproductive costs is widespread. Instances where the evidence of costs is equivocal are usually caused by using among-individual correlations to study what is a within-individual phenomenon.


1996 ◽  
Vol 351 (1345) ◽  
pp. 1349-1359 ◽  

Analysis of life history evolution in spatially heterogeneous environments was revolutionized by the demonstration by Kawecki & Stearns (1993) and Houston & McNamara (1992) that earlier treatments had used incorrect fitness measures. The implications of this for the analysis of organisms with and without phenotypic plasticity are reviewed. It is shown that analyses ignoring age structure can give misleading results. The plausibility and implications of the assumptions are discussed, and suggestions are made for further work. The usefulness of reciprocal transplant and common garden experiments, in providing information relevant to the assumptions and predictions, is emphasized. Two simulation studies show that life history evolution in temporally heterogeneous environments in which trade-offs are fixed are well predicted by Schaffer’s (1974) model, with modification for asymmetric variations as necessary. Unfortunately the period of study needed to observe such effects is so long as to preclude experimental tests for most organsims.


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