scholarly journals Reproductive Allocation and Maternal Investment in Intertidal Whelks

2021 ◽  
Author(s):  
◽  
John Van der Sman
Keyword(s):  
Life History ◽  
Maternal Nutrition ◽  
Maternal Investment ◽  
Reproductive Allocation ◽  
Life History Trait ◽  
Offspring Size ◽  
Juvenile Growth ◽  
Negative Consequences ◽  
Growth And Survival ◽  
Trade Offs

<p>Parental investment per offspring is a key life history trait in which offspring size and number combinations are balanced in order to maximise fitness. When food is scarce and energy for reproduction is reduced, changes in reproductive allocation can be expected. These adjustments may go on to influence the growth and survival of the next generation. Trade-offs in reproductive allocation in response to food availability occurred differently in each of the three whelks species of this study. However, each species traded numbers of offspring rather than size of offspring when fed low food. Offspring size was more variable among and within capsules than among food treatments. Capsule size was a plastic trait that varied in response to food treatments in each of the species and varied among populations of the same species. Carry-over effects of maternal nutrition influenced juvenile growth in all three species. However, while juvenile growth was greater when adults were fed high food in two of the species, high adult food suppressed the growth of juveniles of the third species. This may be a mechanism to prevent potential negative consequences of rapid growth. There was no evidence of a maternal effect of mortality in any of the three species. Greater variation in hatchling size occurred in the species in which nurse egg feeding occurred. Nurse egg feeding may be a successful strategy in unpredictable environments where optimal offspring size changes from year to year. Regional differences in reproductive allocation between whelks separated by small distances suggest that populations may be isolated from one another and may need to be managed separately for conservation purposes. This study highlights the influence of maternal nutritional effects on life history and the potential impacts that these may have on population and community structure.</p>

scholarly journals Reproductive Allocation and Maternal Investment in Intertidal Whelks

2021 ◽  
Author(s):  
◽  
John Van der Sman
Keyword(s):  
Life History ◽  
Maternal Nutrition ◽  
Maternal Investment ◽  
Reproductive Allocation ◽  
Life History Trait ◽  
Offspring Size ◽  
Juvenile Growth ◽  
Negative Consequences ◽  
Growth And Survival ◽  
Trade Offs

<p>Parental investment per offspring is a key life history trait in which offspring size and number combinations are balanced in order to maximise fitness. When food is scarce and energy for reproduction is reduced, changes in reproductive allocation can be expected. These adjustments may go on to influence the growth and survival of the next generation. Trade-offs in reproductive allocation in response to food availability occurred differently in each of the three whelks species of this study. However, each species traded numbers of offspring rather than size of offspring when fed low food. Offspring size was more variable among and within capsules than among food treatments. Capsule size was a plastic trait that varied in response to food treatments in each of the species and varied among populations of the same species. Carry-over effects of maternal nutrition influenced juvenile growth in all three species. However, while juvenile growth was greater when adults were fed high food in two of the species, high adult food suppressed the growth of juveniles of the third species. This may be a mechanism to prevent potential negative consequences of rapid growth. There was no evidence of a maternal effect of mortality in any of the three species. Greater variation in hatchling size occurred in the species in which nurse egg feeding occurred. Nurse egg feeding may be a successful strategy in unpredictable environments where optimal offspring size changes from year to year. Regional differences in reproductive allocation between whelks separated by small distances suggest that populations may be isolated from one another and may need to be managed separately for conservation purposes. This study highlights the influence of maternal nutritional effects on life history and the potential impacts that these may have on population and community structure.</p>

scholarly journals The influence of juvenile and adult environments on life-history trajectories

2005 ◽  
Vol 273 (1587) ◽  
pp. 741-750 ◽  
Author(s):  
Barbara Taborsky
Keyword(s):  
Life History ◽  
Life Histories ◽  
Adult Life ◽  
Growth Conditions ◽  
Offspring Size ◽  
Juvenile Growth ◽  
Life History Variation ◽  
Major Life ◽  
Adult Growth ◽  
Trade Offs

There is increasing evidence that the environment experienced early in life can strongly influence adult life histories. It is largely unknown, however, how past and present conditions influence suites of life-history traits regarding major life-history trade-offs. Especially in animals with indeterminate growth, we may expect that environmental conditions of juveniles and adults independently or interactively influence the life-history trade-off between growth and reproduction after maturation. Juvenile growth conditions may initiate a feedback loop determining adult allocation patterns, triggered by size-dependent mortality risk. I tested this possibility in a long-term growth experiment with mouthbrooding cichlids. Females were raised either on a high-food or low-food diet. After maturation half of them were switched to the opposite treatment, while the other half remained unchanged. Adult growth was determined by current resource availability, but key reproductive traits like reproductive rate and offspring size were only influenced by juvenile growth conditions, irrespective of the ration received as adults. Moreover, the allocation of resources to growth versus reproduction and to offspring number versus size were shaped by juvenile rather than adult ecology. These results indicate that early individual history must be considered when analysing causes of life-history variation in natural populations.

Reproductive Allocation in Animals

Ecology ◽  
2012 ◽  
Author(s):  
James Gilbert
Keyword(s):  
Body Weight ◽  
Life History ◽  
Behavioral Ecology ◽  
Energy Budget ◽  
Reproductive Allocation ◽  
Model Systems ◽  
Offspring Size ◽  
Tsetse Flies ◽  
Time Reproduction ◽  
Trade Offs

Reproductive allocation is a term used in ecology and evolutionary biology that refers to the proportion of an organism’s energy budget allocated to reproduction at any given time. Reproduction must be balanced (or traded off) against opposing expenditures such as growth, survival, maintenance, and future reproduction. The term also covers division of resources among offspring size and number. Studying reproductive allocation trade-offs is fundamental to the fields of behavioral ecology and physiological ecology, which use evolutionary theory to explain and predict animal behavior and physiology, respectively. More specifically, these trade-offs are central to the field of life history, which studies how growth and reproduction is distributed across animals’ lifetimes. Animals show a vast degree of variation in reproductive allocation. Kiwis, for example, famously lay a single egg that is up to 20 percent of body weight. As if this were nothing, caecilians (amphibians) can bear live litters of offspring that are up to 65 percent of the mother’s body weight. Egg numbers vary enormously and can reach spectacular numbers: tsetse flies bear as few as six live offspring in a lifetime, whereas ghost moths can lay more than 50,000 eggs. Social insects have truly mind-boggling fecundity: driver ants can lay several million eggs per month, and can live for decades; ocean sunfish release about 300 million eggs at a time, more than any other vertebrate. At the other extreme, very many organisms have one offspring at a time. Usually this goes hand in hand with repeated breeding, but perhaps the most puzzling of allocation decisions is found in dung beetles, which have only one ovary; some species lay as few as five to ten eggs. Careful parental care ensures that more than 90 percent of offspring survive, explaining why these species have not become extinct. Clearly, variation of this order of magnitude requires evolutionary explanation. Research into reproductive allocation has progressed from a simple household-economics outlook based on the division of a fixed energy budget toward more sophisticated approaches based on quantitative and mechanistic genetics. Of particular use have been model systems such as Drosophila and Daphnia, where traits of reproductive allocation (body size, egg size, egg number, etc.) have become model traits for modern genetic analyses. Modern approaches to reproductive allocation typically involve elucidating genetic bases for trade-offs expressed across a range of environments. Nevertheless, the classical life history approaches remain relevant, especially in systems in which controlled quantitative genetics are not possible.

scholarly journals Mapping the adaptive landscape of a major agricultural pathogen reveals evolutionary constraints across heterogeneous environments

2021 ◽  
Author(s):  
Anik Dutta ◽  
Fanny E. Hartmann ◽  
Carolina Sardinha Francisco ◽  
Bruce A. McDonald ◽  
Daniel Croll
Keyword(s):  
Life History ◽  
Large Scale ◽  
Life History Traits ◽  
Genetic Correlations ◽  
Stress Factors ◽  
Life History Trait ◽  
Adaptive Landscape ◽  
Heterogeneous Environments ◽  
Growth Responses ◽  
Trade Offs

AbstractThe adaptive potential of pathogens in novel or heterogeneous environments underpins the risk of disease epidemics. Antagonistic pleiotropy or differential resource allocation among life-history traits can constrain pathogen adaptation. However, we lack understanding of how the genetic architecture of individual traits can generate trade-offs. Here, we report a large-scale study based on 145 global strains of the fungal wheat pathogen Zymoseptoria tritici from four continents. We measured 50 life-history traits, including virulence and reproduction on 12 different wheat hosts and growth responses to several abiotic stressors. To elucidate the genetic basis of adaptation, we used genome-wide association mapping coupled with genetic correlation analyses. We show that most traits are governed by polygenic architectures and are highly heritable suggesting that adaptation proceeds mainly through allele frequency shifts at many loci. We identified negative genetic correlations among traits related to host colonization and survival in stressful environments. Such genetic constraints indicate that pleiotropic effects could limit the pathogen’s ability to cause host damage. In contrast, adaptation to abiotic stress factors was likely facilitated by synergistic pleiotropy. Our study illustrates how comprehensive mapping of life-history trait architectures across diverse environments allows to predict evolutionary trajectories of pathogens confronted with environmental perturbations.

scholarly journals Adaptive Maternal Investment in the Wild? Links between Maternal Growth Trajectory and Offspring Size, Growth, and Survival in Contrasting Environments

2020 ◽  
Vol 195 (4) ◽  
pp. 678-690
Author(s):  
Tim Burton ◽  
Njal Rollinson ◽  
Simon McKelvey ◽  
David C. Stewart ◽  
John D. Armstrong ◽  
...  
Keyword(s):  
Maternal Investment ◽  
Growth Trajectory ◽  
Offspring Size ◽  
Growth And Survival ◽  
Size Growth ◽  
In The Wild

scholarly journals Why does offspring size affect performance? Integrating metabolic scaling with life-history theory

2015 ◽  
Vol 282 (1819) ◽  
pp. 20151946 ◽  
Author(s):  
Amanda K. Pettersen ◽  
Craig R. White ◽  
Dustin J. Marshall
Keyword(s):  
Life History ◽  
Life History Theory ◽  
Maternal Investment ◽  
Offspring Size ◽  
Metabolic Efficiency ◽  
Metabolic Scaling ◽  
And Performance ◽  
The Relationship ◽  
General Explanation ◽  
Better Than

Within species, larger offspring typically outperform smaller offspring. While the relationship between offspring size and performance is ubiquitous, the cause of this relationship remains elusive. By linking metabolic and life-history theory, we provide a general explanation for why larger offspring perform better than smaller offspring. Using high-throughput respirometry arrays, we link metabolic rate to offspring size in two species of marine bryozoan. We found that metabolism scales allometrically with offspring size in both species: while larger offspring use absolutely more energy than smaller offspring, larger offspring use proportionally less of their maternally derived energy throughout the dependent, non-feeding phase. The increased metabolic efficiency of larger offspring while dependent on maternal investment may explain offspring size effects—larger offspring reach nutritional independence (feed for themselves) with a higher proportion of energy relative to structure than smaller offspring. These findings offer a potentially universal explanation for why larger offspring tend to perform better than smaller offspring but studies on other taxa are needed.

Effect of body size, age and timing of breeding on clutch and egg size of female Eastern Gray Treefrogs, Hyla versicolor

2021 ◽  
pp. 1-11
Author(s):  
Gerlinde Höbel ◽  
Robb Kolodziej ◽  
Dustin Nelson ◽  
Christopher White
Keyword(s):  
Life History ◽  
Egg Size ◽  
Life History Theory ◽  
Reproductive Investment ◽  
Ecological Factors ◽  
Hyla Versicolor ◽  
Growth And Survival ◽  
Factors Affecting ◽  
Trade Offs ◽  
Gray Treefrogs

Abstract Information on how organisms allocate resources to reproduction is critical for understanding population dynamics. We collected clutch size (fecundity) and egg size data of female Eastern Gray Treefrogs, Hyla versicolor, and examined whether observed patterns of resource allocation are best explained by expectations arising from life history theory or by expected survival and growth benefits of breeding earlier. Female Hyla versicolor showed high between-individual variation in clutch and egg size. We did not observe maternal allocation trade-offs (size vs number; growth vs reproduction) predicted from life history theory, which we attribute to the large between-female variation in resource availability, and the low survival and post-maturity growth rate observed in the study population. Rather, clutches are larger at the beginning of the breeding season, and this variation in reproductive investment aligns with seasonal variation in ecological factors affecting offspring growth and survival.

scholarly journals Longevity and ageing: appraising the evolutionary consequences of growing old

2005 ◽  
Vol 361 (1465) ◽  
pp. 119-135 ◽  
Author(s):  
Michael B Bonsall
Keyword(s):  
Life History ◽  
Biological Diversity ◽  
Species Coexistence ◽  
Life History Strategies ◽  
Life History Trait ◽  
Future Research ◽  
Ecological Processes ◽  
Physiological Processes ◽  
Trade Offs ◽  
Evolutionary Consequences

Senescence or ageing is an increase in mortality and/or decline in fertility with increasing age. Evolutionary theories predict that ageing or longevity evolves in response to patterns of extrinsic mortality or intrinsic damage. If ageing is viewed as the outcome of the processes of behaviour, growth and reproduction then it should be possible to predict mortality rate. Recent developments have shown that it is now possible to integrate these ecological and physiological processes and predict the shape of mortality trajectories. By drawing on the key exciting developments in the cellular, physiological and ecological process of longevity the evolutionary consequences of ageing are reviewed. In presenting these ideas an evolutionary demographic framework is used to argue how trade-offs in life-history strategies are important in the maintenance of variation in longevity within and between species. Evolutionary processes associated with longevity have an important role in explaining levels of biological diversity and speciation. In particular, the effects of life-history trait trade-offs in maintaining and promoting species diversity are explored. Such trade-offs can alleviate the effects of intense competition between species and promote species coexistence and diversification. These results have important implications for understanding a number of core ecological processes such as how species are divided among niches, how closely related species co-occur and the rules by which species assemble into food-webs. Theoretical work reveals that the proximate physiological processes are as important as the ecological factors in explaining the variation in the evolution of longevity. Possible future research challenges integrating work on the evolution and mechanisms of growing old are briefly discussed.

Parental crowding influences life-history traits inLocusta migratoriafemales

2009 ◽  
Vol 100 (1) ◽  
pp. 9-17 ◽  
Author(s):  
M.-P. Chapuis ◽  
L. Crespin ◽  
A. Estoup ◽  
A. Augé-Sabatier ◽  
A. Foucart ◽  
...  
Keyword(s):  
Life History ◽  
Parental Influence ◽  
Life History Traits ◽  
Locusta Migratoria ◽  
Developmental Time ◽  
Life History Trait ◽  
Offspring Size ◽  
Potential Implication ◽  
Generational Effects ◽  
History Of

AbstractParental environments could play an important role in controlling insect outbreaks, provided they influence changes in physiological, developmental or behavioural life-history traits related to fluctuations in population density. However, the potential implication of parental influence in density-related changes in life-history traits remains unclear in many insects that exhibit fluctuating population dynamics, particularly locusts. In this study, we report a laboratory experiment, which enabled us to characterize the life-history trait modifications induced by parental crowding of female individuals from a frequently outbreaking population ofLocusta migratoria(Linnaeus) (Orthoptera: Acrididae). We found that a rearing history of crowding led to reduced female oviposition times and increased offspring size but did not affect the developmental time, survival, fecundity, and the sex-ratio and the number of offspring. Because all studied females were raised in a common environment (isolation conditions), these observed reproductive differences are due to trans-generational effects induced by density. We discuss the ecological and evolutionary implications of the observed density-dependent parental effects on the life-history ofL. migratoria.

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