title: Impacts of dispersal on rapid adaptation and dynamic stability of Daphnia in fluctuating environments.
abstract: Prior ecological research has shown that spatial processes can enhance the temporal stability of populations in fluctuating environments. Less explored is the effect of dispersal on rapid adaptation and its concomitant impact on population dynamics. For asexually reproducing populations, theory predicts that dispersal in fluctuating environments can facilitate asynchrony among clones and enhance stability by reducing temporal variability of total population abundance. This effect is predicted when clones exhibit heritable variation in environmental optima and when fluctuations occur asynchronously among patches. We tested this in the field using artificial ponds and metapopulations composed of a diverse assemblage of Daphnia pulex clones. We directly manipulated dispersal presence/absence and environmental fluctuations in the form of nutrient pulses. Consistent with predictions, dispersal enhanced temporal asynchrony among clones in the presence of nutrient pulses; this in turn stabilized population dynamics. This effect only emerged when patches experienced spatially asynchronous nutrient pulses (dispersal had no effect when patches were synchronously pulsed). Clonal asynchrony was driven by strong positive selection for a single clone that exhibited a performance advantage under conditions of low resource availability. Our work highlights the importance of dispersal as a driver of eco-evolutionary dynamics and population stability in variable environments.
authors.affiliation: Department of Biological Sciences, Wayne State University, Biological Sciences Building, 5047 Gullen Mall, Detroit, MI 48202, USA csteiner@wayne.edu.
authors.forename: Christopher F
authors.initials: CF
authors.lastname: Steiner
authors.affiliation: Department of Biological Sciences, Wayne State University, Biological Sciences Building, 5047 Gullen Mall, Detroit, MI 48202, USA.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Stockwell
authors.affiliation: Department of Biological Sciences, Wayne State University, Biological Sciences Building, 5047 Gullen Mall, Detroit, MI 48202, USA.
authors.forename: Monica
authors.initials: M
authors.lastname: Tadros
authors.affiliation: Department of Biological Sciences, Wayne State University, Biological Sciences Building, 5047 Gullen Mall, Detroit, MI 48202, USA.
authors.forename: Laith
authors.initials: L
authors.lastname: Shaman
authors.affiliation: Department of Biological Sciences, Wayne State University, Biological Sciences Building, 5047 Gullen Mall, Detroit, MI 48202, USA.
authors.forename: Komal
authors.initials: K
authors.lastname: Patel
authors.affiliation: Department of Biological Sciences, Wayne State University, Biological Sciences Building, 5047 Gullen Mall, Detroit, MI 48202, USA.
authors.forename: Laila
authors.initials: L
authors.lastname: Khraizat
mesh_terms: D000220:Adaptation, Biological; D063147:Animal Distribution; D000818:Animals; D003621:Daphnia / Q000235:genetics / Q000502:physiology*; D061005:Ponds; D011157:Population Dynamics; D012621:Seasons; D012641:Selection, Genetic
keywords: compensatory dynamics; dispersal; eco-evolutionary dynamics; fluctuating selection; metapopulation; stability