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