A fitness trade-off between seasons causes multigenerational cycles in phenotype and population size.
Although seasonality is widespread and can cause fluctuations in the intensity and direction of natural selection, we have little information about the consequences of seasonal fitness trade-offs for population dynamics. Here we exposed populations ofDrosophila melanogasterto repeated seasonal changes in resources across 58 generations and used experimental and mathematical approaches to investigate how viability selection on body size in the non-breeding season could affect demography. We show that opposing seasonal episodes of natural selection on body size interacted with both direct and delayed density dependence to cause populations to undergo predictable multigenerational density cycles. Our results provide evidence that seasonality can set the conditions for life-history trade-offs and density dependence, which can, in turn, interact to cause multigenerational population cycles.
Department of Integrative Biology, University of Guelph, Guelph, Canada.
Gustavo S
0000-0003-0707-4128
GS
Betini
Department of Integrative Biology, University of Guelph, Guelph, Canada.
Andrew G
0000-0001-7323-2572
AG
McAdam
Department of Integrative Biology, University of Guelph, Guelph, Canada.
Cortland K
CK
Griswold
Department of Integrative Biology, University of Guelph, Guelph, Canada.
D Ryan
0000-0003-4874-1425
DR
Norris
D000818:Animals; D000073537:Biological Variation, Population; D004331:Drosophila melanogaster / Q000502:physiology*; D056084:Genetic Fitness; D008962:Models, Theoretical; D011156:Population Density; D012621:Seasons
D. melanogaster; Drosophila melanogaster; body size; density dependence; eco-evolutionary dynamics; ecology; evolutionary biology; genomics; seasonal cycle