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Optimal resource allocation to survival and reproduction in parasitic wasps foraging in fragmented habitats.

Wajnberg E, Coquillard P, Vet LE, Hoffmeister T - PLoS ONE (2012)

Bottom Line: Although the associated ecological consequences have been studied by several authors, the evolutionary effects on interacting species have received little research attention.As observed in real animal species, the model is based on the existence of a negative trade-off between survival and reproduction resulting from competitive allocation of resources to either somatic maintenance or egg production.The evolutionary consequences of these results are discussed.

View Article: PubMed Central - PubMed

Affiliation: INRA, Sophia Antipolis Cedex, France. wajnberg@sophia.inra.fr

ABSTRACT
Expansion and intensification of human land use represents the major cause of habitat fragmentation. Such fragmentation can have dramatic consequences on species richness and trophic interactions within food webs. Although the associated ecological consequences have been studied by several authors, the evolutionary effects on interacting species have received little research attention. Using a genetic algorithm, we quantified how habitat fragmentation and environmental variability affect the optimal reproductive strategies of parasitic wasps foraging for hosts. As observed in real animal species, the model is based on the existence of a negative trade-off between survival and reproduction resulting from competitive allocation of resources to either somatic maintenance or egg production. We also asked to what degree plasticity along this trade-off would be optimal, when plasticity is costly. We found that habitat fragmentation can indeed have strong effects on the reproductive strategies adopted by parasitoids. With increasing habitat fragmentation animals should invest in greater longevity with lower fecundity; yet, especially in unpredictable environments, some level of phenotypic plasticity should be selected for. Other consequences in terms of learning ability of foraging animals were also observed. The evolutionary consequences of these results are discussed.

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Effect of habitat patch quality and inter-patch travel time on the optimized values of the parameter G1.Average (±SE) optimized values for the parameter G1 defining the initial reproductive strategy on the trade-off between longevity and egg load (see Figure 1) for parasitoid females foraging for hosts in environments with different habitat patch qualities and different inter-patch travel times.
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pone-0038227-g002: Effect of habitat patch quality and inter-patch travel time on the optimized values of the parameter G1.Average (±SE) optimized values for the parameter G1 defining the initial reproductive strategy on the trade-off between longevity and egg load (see Figure 1) for parasitoid females foraging for hosts in environments with different habitat patch qualities and different inter-patch travel times.

Mentions: Parasitoid females should invest less in fecundity and more in longevity when they are foraging in habitats that are more fragmented, i.e., with smaller habitat patches and with longer travel times to reach them (effect of habitat patch quality: F6,736 = 1292.72, p<0.0001; effect of travel time: F4,736 = 106.37, p<0.0001; Fig. 2). Furthermore, the higher the probability that a female starts her life in a host-containing environment, i.e., the lower the probability of initial dispersing to a new habitat, the more the parasitoid should invest in higher fecundity with lower longevity (F4,736 = 111.01, p<0.0001; Fig. 3).


Optimal resource allocation to survival and reproduction in parasitic wasps foraging in fragmented habitats.

Wajnberg E, Coquillard P, Vet LE, Hoffmeister T - PLoS ONE (2012)

Effect of habitat patch quality and inter-patch travel time on the optimized values of the parameter G1.Average (±SE) optimized values for the parameter G1 defining the initial reproductive strategy on the trade-off between longevity and egg load (see Figure 1) for parasitoid females foraging for hosts in environments with different habitat patch qualities and different inter-patch travel times.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3368906&req=5

pone-0038227-g002: Effect of habitat patch quality and inter-patch travel time on the optimized values of the parameter G1.Average (±SE) optimized values for the parameter G1 defining the initial reproductive strategy on the trade-off between longevity and egg load (see Figure 1) for parasitoid females foraging for hosts in environments with different habitat patch qualities and different inter-patch travel times.
Mentions: Parasitoid females should invest less in fecundity and more in longevity when they are foraging in habitats that are more fragmented, i.e., with smaller habitat patches and with longer travel times to reach them (effect of habitat patch quality: F6,736 = 1292.72, p<0.0001; effect of travel time: F4,736 = 106.37, p<0.0001; Fig. 2). Furthermore, the higher the probability that a female starts her life in a host-containing environment, i.e., the lower the probability of initial dispersing to a new habitat, the more the parasitoid should invest in higher fecundity with lower longevity (F4,736 = 111.01, p<0.0001; Fig. 3).

Bottom Line: Although the associated ecological consequences have been studied by several authors, the evolutionary effects on interacting species have received little research attention.As observed in real animal species, the model is based on the existence of a negative trade-off between survival and reproduction resulting from competitive allocation of resources to either somatic maintenance or egg production.The evolutionary consequences of these results are discussed.

View Article: PubMed Central - PubMed

Affiliation: INRA, Sophia Antipolis Cedex, France. wajnberg@sophia.inra.fr

ABSTRACT
Expansion and intensification of human land use represents the major cause of habitat fragmentation. Such fragmentation can have dramatic consequences on species richness and trophic interactions within food webs. Although the associated ecological consequences have been studied by several authors, the evolutionary effects on interacting species have received little research attention. Using a genetic algorithm, we quantified how habitat fragmentation and environmental variability affect the optimal reproductive strategies of parasitic wasps foraging for hosts. As observed in real animal species, the model is based on the existence of a negative trade-off between survival and reproduction resulting from competitive allocation of resources to either somatic maintenance or egg production. We also asked to what degree plasticity along this trade-off would be optimal, when plasticity is costly. We found that habitat fragmentation can indeed have strong effects on the reproductive strategies adopted by parasitoids. With increasing habitat fragmentation animals should invest in greater longevity with lower fecundity; yet, especially in unpredictable environments, some level of phenotypic plasticity should be selected for. Other consequences in terms of learning ability of foraging animals were also observed. The evolutionary consequences of these results are discussed.

Show MeSH
Related in: MedlinePlus