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The plastic fly: the effect of sustained fluctuations in adult food supply on life-history traits.

van den Heuvel J, Zandveld J, Mulder M, Brakefield PM, Kirkwood TB, Shanley DP, Zwaan BJ - J. Evol. Biol. (2014)

Bottom Line: Remarkably, both the manner and extent to which life-history traits varied in relation to food depended on whether flies initially experienced high or low food after eclosion.We therefore conclude that the expression of life-history traits in adult life is affected not only by adult plasticity, but also by early adult life experiences.This is an important but often overlooked factor in studies of life-history evolution and may explain variation in life-history experiments.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Genetics, Wageningen University, Wageningen, The Netherlands; Evolutionary Biology Group, Leiden University, Leiden, The Netherlands; Institute for Ageing and Health, Newcastle University, Campus for Aging and Vitality, Newcastle Upon Tyne, UK.

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A schematic overview for the outcome of the two experiments. High and low food treatments are indicated by the H and L at the stem of the ‘Y’. We quantified the life-history traits survival (S) and virgin egg production (R) which are indications of how the acquired resources are allocated (by the width of the stem). In experiment 1 and 2, survival is higher at high food represented here by a broader branch towards survival. In Exp #1, no other target for allocation of resource was quantified; we represent any other resource allocation by the dashed branch. The other trait measured, weight, was higher at higher food, indicated by the ‘fat’ fly at high food and the ‘slender’ fly at low food. In Exp #2, we also quantified the number of eggs: at high food, allocation to survival was high but to egg production low, whereas the reverse was true for low food. In Exp #2, a smaller amount of the acquired resource has an unknown allocation (dashed branch). Weight was equal between high and low food in Exp #2 shown by the equal flies. In both experiments, the general scenario of differential allocation holds, but the detailed relationships between acquisition and allocation of resource varies with yoyo treatment and especially initial food level experienced in the early adult life of a fruit fly. Yoyo treatment and initial food level could have affected the details of the outcome in three ways, namely (A) by variation in acquisition, (B) by variation in allocation and (C) by a combination of acquisition and allocation. Lastly, there are differences mainly in weight between experiments.
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fig08: A schematic overview for the outcome of the two experiments. High and low food treatments are indicated by the H and L at the stem of the ‘Y’. We quantified the life-history traits survival (S) and virgin egg production (R) which are indications of how the acquired resources are allocated (by the width of the stem). In experiment 1 and 2, survival is higher at high food represented here by a broader branch towards survival. In Exp #1, no other target for allocation of resource was quantified; we represent any other resource allocation by the dashed branch. The other trait measured, weight, was higher at higher food, indicated by the ‘fat’ fly at high food and the ‘slender’ fly at low food. In Exp #2, we also quantified the number of eggs: at high food, allocation to survival was high but to egg production low, whereas the reverse was true for low food. In Exp #2, a smaller amount of the acquired resource has an unknown allocation (dashed branch). Weight was equal between high and low food in Exp #2 shown by the equal flies. In both experiments, the general scenario of differential allocation holds, but the detailed relationships between acquisition and allocation of resource varies with yoyo treatment and especially initial food level experienced in the early adult life of a fruit fly. Yoyo treatment and initial food level could have affected the details of the outcome in three ways, namely (A) by variation in acquisition, (B) by variation in allocation and (C) by a combination of acquisition and allocation. Lastly, there are differences mainly in weight between experiments.

Mentions: We examined whether adult flies kept on food that varied over time differed in life-history traits from those maintained on constant food. Figure8 gives an overview of the effects found of variation in food level on the measured traits. Survival of flies on sustained varying food was not lower than that of controls. The former showed an intermediate survival and the control flies on low food had a decreased survival compared to those on several other food treatments. This suggests that there is little, if any, cost in being variable in weight (Exp #1) or in the number of eggs produced (Exp #2). Strikingly, the lifespan was very similar across experiments when food treatments were compared. Most interestingly, in addition to evidence of adult plasticity, there was also a large effect on life-history traits throughout life of the initial food level experienced by a fly after eclosion. A similar effect of early adult experience was shown by Pearl et al. (1927) where flies were kept in bottles with various densities which affected lifespan. For instance, when a fly was transferred from a bottle in which the density was 35 flies to one of 200 at the 16th day of age, they lived longer than flies that lived under a density of 200 throughout life (Pearl et al., 1927). Our study on nutrition and Pearl et al.'s study of the effect of density, demonstrate the importance of early adult life experience.


The plastic fly: the effect of sustained fluctuations in adult food supply on life-history traits.

van den Heuvel J, Zandveld J, Mulder M, Brakefield PM, Kirkwood TB, Shanley DP, Zwaan BJ - J. Evol. Biol. (2014)

A schematic overview for the outcome of the two experiments. High and low food treatments are indicated by the H and L at the stem of the ‘Y’. We quantified the life-history traits survival (S) and virgin egg production (R) which are indications of how the acquired resources are allocated (by the width of the stem). In experiment 1 and 2, survival is higher at high food represented here by a broader branch towards survival. In Exp #1, no other target for allocation of resource was quantified; we represent any other resource allocation by the dashed branch. The other trait measured, weight, was higher at higher food, indicated by the ‘fat’ fly at high food and the ‘slender’ fly at low food. In Exp #2, we also quantified the number of eggs: at high food, allocation to survival was high but to egg production low, whereas the reverse was true for low food. In Exp #2, a smaller amount of the acquired resource has an unknown allocation (dashed branch). Weight was equal between high and low food in Exp #2 shown by the equal flies. In both experiments, the general scenario of differential allocation holds, but the detailed relationships between acquisition and allocation of resource varies with yoyo treatment and especially initial food level experienced in the early adult life of a fruit fly. Yoyo treatment and initial food level could have affected the details of the outcome in three ways, namely (A) by variation in acquisition, (B) by variation in allocation and (C) by a combination of acquisition and allocation. Lastly, there are differences mainly in weight between experiments.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263262&req=5

fig08: A schematic overview for the outcome of the two experiments. High and low food treatments are indicated by the H and L at the stem of the ‘Y’. We quantified the life-history traits survival (S) and virgin egg production (R) which are indications of how the acquired resources are allocated (by the width of the stem). In experiment 1 and 2, survival is higher at high food represented here by a broader branch towards survival. In Exp #1, no other target for allocation of resource was quantified; we represent any other resource allocation by the dashed branch. The other trait measured, weight, was higher at higher food, indicated by the ‘fat’ fly at high food and the ‘slender’ fly at low food. In Exp #2, we also quantified the number of eggs: at high food, allocation to survival was high but to egg production low, whereas the reverse was true for low food. In Exp #2, a smaller amount of the acquired resource has an unknown allocation (dashed branch). Weight was equal between high and low food in Exp #2 shown by the equal flies. In both experiments, the general scenario of differential allocation holds, but the detailed relationships between acquisition and allocation of resource varies with yoyo treatment and especially initial food level experienced in the early adult life of a fruit fly. Yoyo treatment and initial food level could have affected the details of the outcome in three ways, namely (A) by variation in acquisition, (B) by variation in allocation and (C) by a combination of acquisition and allocation. Lastly, there are differences mainly in weight between experiments.
Mentions: We examined whether adult flies kept on food that varied over time differed in life-history traits from those maintained on constant food. Figure8 gives an overview of the effects found of variation in food level on the measured traits. Survival of flies on sustained varying food was not lower than that of controls. The former showed an intermediate survival and the control flies on low food had a decreased survival compared to those on several other food treatments. This suggests that there is little, if any, cost in being variable in weight (Exp #1) or in the number of eggs produced (Exp #2). Strikingly, the lifespan was very similar across experiments when food treatments were compared. Most interestingly, in addition to evidence of adult plasticity, there was also a large effect on life-history traits throughout life of the initial food level experienced by a fly after eclosion. A similar effect of early adult experience was shown by Pearl et al. (1927) where flies were kept in bottles with various densities which affected lifespan. For instance, when a fly was transferred from a bottle in which the density was 35 flies to one of 200 at the 16th day of age, they lived longer than flies that lived under a density of 200 throughout life (Pearl et al., 1927). Our study on nutrition and Pearl et al.'s study of the effect of density, demonstrate the importance of early adult life experience.

Bottom Line: Remarkably, both the manner and extent to which life-history traits varied in relation to food depended on whether flies initially experienced high or low food after eclosion.We therefore conclude that the expression of life-history traits in adult life is affected not only by adult plasticity, but also by early adult life experiences.This is an important but often overlooked factor in studies of life-history evolution and may explain variation in life-history experiments.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Genetics, Wageningen University, Wageningen, The Netherlands; Evolutionary Biology Group, Leiden University, Leiden, The Netherlands; Institute for Ageing and Health, Newcastle University, Campus for Aging and Vitality, Newcastle Upon Tyne, UK.

Show MeSH
Related in: MedlinePlus