Phenotypic plasticity allows the Mediterranean parsley frog Pelodytes punctatus to exploit two temporal niches under continuous gene flow.
Environmental changes, such as climate change, lead to the opening of new niches. In such situations, species that adapt to new niches can survive and/or expand their ranges. However, gene flow can hamper genetic adaptation to new environments. Alternatively, recent models have highlighted the importance of phenotypic plasticity in tracking environmental change. Here, we investigate whether phenotypic plasticity or genetic evolution (or both) allows an amphibian species to exploit two divergent climatic niches. In the Mediterranean region, the parsley frog Pelodytes punctatus breeds both in spring, as do most other species, and in autumn, a temporal niche not exploited by most other species, but which may become increasingly important with global warming. Conditions of development are dramatically different between the two seasons and deeply impact tadpole life-history traits. To determine whether these temporal niches are exploited by two genetically differentiated subpopulations, or whether the bimodal phenology arises in a panmictic population displaying plastic life-history traits, we use two complementary approaches. We measure both molecular genetic differentiation and quantitative-trait differentiation between spring and autumn cohorts, using microsatellites and common garden experiments, respectively. Seasonal cohorts were not genetically differentiated and differences in tadpole life history between cohorts were not maintained in laboratory conditions. We conclude that phenotypic plasticity, rather than genetic adaptation, allows Parsley frog to exploit two contrasting temporal niches.
Centre d'Ecologie Fonctionnelle et Evolutive, UMR 5175 CNRS, 1919 route de Mende, 34293 Montpellier Cedex 5, France. helene.jourdan@unil.ch
Helene
H
Jourdan-Pineau
Patrice
P
David
Pierre-Andre
PA
Crochet
D000818:Animals; D001001:Anura / Q000235:genetics* / Q000502:physiology; D017753:Ecosystem; D051456:Gene Flow; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D007814:Larva / Q000235:genetics / Q000502:physiology; D019083:Mediterranean Region; D010641:Phenotype; D012621:Seasons; D017422:Sequence Analysis, DNA