Evolutionary Optimality Applied to Drosophila Experiments: Hypothesis of Constrained Reproductive Efficiency

Novoseltsev, V. N.; Arking, Robert; Novoseltseva, Janna; Yashin, Anatoli I.

doi:10.1111/j.0014-3820.2002.tb01427.x

Cited by 23 publications

(7 citation statements)

References 64 publications

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“…In general, the allocation of more effort to the acquisition of energy results in a decrease in oviposition activity. This change in the rate of oviposition as a function of the age of the individual is frequently observed in insects (Partridge et al 1987, Boggs 1997, Novoseltsev et al 2002. These changes may be attributed, at least in our case, to the exhaustion of capital reserves (Giron and Casas 2003).…”

Section: Assumptions Of the Modelsupporting

confidence: 69%

Stochasticity and controllability of nutrient sources in foraging: host‐feeding and egg resorption in parasitoids

Richard

Casas

2009

Ecological Monographs

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Abstract. The trade-off between current and future reproduction has led many organisms experiencing stochastic reproductive opportunities to be flexible in their resource acquisition and allocation rules. Many parasitoid wasps display flexibility in choosing to host-feed or oviposit on a host and possess an ovarian system enabling nutrient reallocation through egg resorption.The aim of this work is to assess the complementary adaptive values of host-feeding and egg resorption as functions of host density in a synovigenic (maturing eggs throughout its adult life) parasitoid, Eupelmus vuilleti (Hymenoptera: Eupelmidae), for which there is a uniquely large base of relevant knowledge. We developed a series of models of increasing complexity, starting from a simple analytical model without egg resorption and moving on to data-rich stochastic dynamic programming models (SDP), without and with resorption.The analytical model enabled the characterization of two, long-and short-term, foraging strategies which determine host usage. Oviposition is favored at low host densities (leading to the short-term strategy), while host-feeding is favored at high host densities (leading to the long-term strategy). The change of strategy occurs abruptly at intermediate host densities. The SPD models not only confirmed these predictions, but also identified smaller regions of decisions driven by day/night cycles and approaching death and predicted major shifts in daily activity patterns according to the chosen strategy. The fitness gain due to resorption is highest at intermediate host densities, where females adopt the riskier but more profitable long-term strategy. Such a result contrasts with the generally held view, which assumes highest gains at the lowest host densities. A counterintuitive result is the higher prevalence of host-feeding associated with the ability to resorb eggs.Considering egg resorption as a last-resort strategy is underestimating its adaptive value, which is best understood with reference to other sources of nutrients. Its deterministic and controllable nature acts as insurance to forage and oviposit at low host densities, despite irregular food availability and potential death through starvation. Thus timing, not so much overall energy gain, matters in egg resorption. The approach can be extended to other situations, and we highlight an unexpected analogy of our results with the hoarding behavior of vertebrates.

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Section: Assumptions Of the Modelsupporting

confidence: 69%

Stochasticity and controllability of nutrient sources in foraging: host‐feeding and egg resorption in parasitoids

Richard

Casas

2009

Ecological Monographs

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“…In D. melanogaster, egg output increases during the first 2-4 days post emergence and remains high for the next 20 days, and thereafter declines gradually (Rose, 1984;Novoseltsev et al, 2002). Our populations, which were maintained on a discrete generation cycle, where egg collection occurred on day 11, showed higher fecundity on day 11 compared with day 4 (Fig.…”

Section: Reproductive Outputmentioning

confidence: 64%

Correlated changes in life history traits in response to selection for faster pre-adult development in the fruit fly Drosophila melanogaster

Yadav

Sharma

2014

Journal of Experimental Biology

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Insects including the fruit fly Drosophila melanogaster are under intense pressure to develop rapidly because they inhabit ephemeral habitats. We have previously shown that when selection for faster development was artificially imposed on D. melanogaster in the laboratory, reduction of pre-adult development time and shortening of the clock period occurs, suggesting a role for circadian clocks in the regulation of life history traits. Circadian clocks in D. melanogaster have also been implicated in the control of metabolic pathways, ageing processes, oxidative stress and defense responses to exogenous stressors. In order to rigorously examine correlations between pre-adult development time and other life history traits, we assayed pre-adult survivorship, starvation and desiccation resistance, body size and body weight, fecundity and adult lifespan in faster developing populations of D. melanogaster. The results revealed that selection for faster pre-adult development significantly reduced several adult fitness traits in the faster developing flies without affecting pre-adult survivorship. Although overall fecundity of faster developing flies was reduced, their egg output per unit body weight was significantly higher than that of controls, indicating that reduction in adult lifespan might be due to disproportionate investment in reproduction. Thus our results suggest that selection for faster preadult development in D. melanogaster yields flies with higher reproductive fitness. Because these flies also have shorter clock periods, our results can be taken to suggest that pre-adult development time and circadian clock period are correlated with various adult life history traits in D. melanogaster, implying that circadian clocks may have adaptive significance.

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“…This anomaly has been established for dogs for some time (Michell, 1999;Li et al, 1996;Patronek et al, 1997;Egenvall et al, 2000). In contrast to these data, however, several studies on different strains of Drosophila (Promislow and Haselkorn, 2002;Novoseltsev et al, 2002;Van Voorhies et al, 2003) show no relationship between energy expenditures and lifespan.…”

Section: (I) Studies Of Transgenic and Natural Mutant Animalsmentioning

confidence: 73%

Body size, energy metabolism and lifespan

Speakman

2005

Journal of Experimental Biology

731

637

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Bigger animals live longer. The scaling exponent for the relationship between lifespan and body mass is between 0.15 and 0.3. Bigger animals also expend more energy, and the scaling exponent for the relationship of resting metabolic rate (RMR) to body mass lies somewhere between 0.66 and 0.8. Mass-specific RMR therefore scales with a corresponding exponent between -0.2 and -0.33. Because the exponents for mass-specific RMR are close to the exponents for lifespan, but have opposite signs, their product (the mass-specific expenditure of energy per lifespan) is independent of body mass (exponent between -0.08 and 0.08). This means that across species a gram of tissue on average expends about the same amount of energy before it dies regardless of whether that tissue is located in a shrew, a cow, an elephant or a whale. This fact led to the notion that ageing and lifespan are processes regulated by energy metabolism rates and that elevating metabolism will be associated with premature mortalitythe rate of living theory.The free-radical theory of ageing provides a potential mechanism that links metabolism to ageing phenomena, since oxygen free radicals are formed as a by-product of oxidative phosphorylation. Despite this potential synergy in these theoretical approaches, the free-radical theory has grown in stature while the rate of living theory has fallen into disrepute. This is primarily because comparisons made across classes (for example, between birds and mammals) do not conform to the expectations, and even within classes there is substantial interspecific variability in the mass-specific expenditure of energy per lifespan. Using interspecific data to test the rate of living hypothesis is, however, confused by several major problems. For example, appeals that the resultant lifetime expenditure of energy per gram of tissue is 'too variable' depend on the biological significance rather than the statistical significance of the variation observed. Moreover, maximum lifespan is not a good marker of ageing and RMR is not a good measure of total energy metabolism. Analysis of residual lifespan against residual RMR reveals no significant relationship. However, this is still based on RMR.A novel comparison using daily energy expenditure (DEE), rather than BMR, suggests that lifetime expenditure of energy per gram of tissue is NOT independent of body mass, and that tissue in smaller animals expends more energy before expiring than tissue in larger animals. Some of the residual variation in this relationship in mammals is explained by ambient temperature. In addition there is a significant negative relationship between residual lifespan and residual daily energy expenditure in mammals. A potentially much better model to explore the links of body size, metabolism and ageing is to examine the intraspecific links. These studies have generated some data that support the original rate of living theory and other data that conflict. In particular several studies have shown that manipulating animals to expend more or less energy ...

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Evolutionary Optimality Applied to Drosophila Experiments: Hypothesis of Constrained Reproductive Efficiency

Cited by 23 publications

References 64 publications

Stochasticity and controllability of nutrient sources in foraging: host‐feeding and egg resorption in parasitoids

Stochasticity and controllability of nutrient sources in foraging: host‐feeding and egg resorption in parasitoids

Correlated changes in life history traits in response to selection for faster pre-adult development in the fruit fly Drosophila melanogaster

Body size, energy metabolism and lifespan

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