Magnitude and predictability of ph fluctuations shape plastic responses to ocean acidification

• Published in: The American Naturalist
• Main Authors: Bitter, Mark C., Kapsenberg, Lydia, Silliman, Katherine, Gattuso, Jean-Pierre, Pfister, Catherine A.
• Other Authors: National Science Foundation (US), Department of Education (US), The University of Chicago Center in Paris, Agencia Estatal de Investigación (España)
• Format: Article in Journal/Newspaper
• Language: English
• Published: University of Chicago Press 2021
• Subjects: Phenotypic plasticity; Fluctuating selection; Environmental predictability; Ocean acidification; Bivalves
• Online Access: http://hdl.handle.net/10261/239730; https://doi.org/10.1086/712930; https://doi.org/10.13039/501100011033; https://doi.org/10.13039/100000138; https://doi.org/10.13039/100000001

16 pages, 5 figures, supplemental material https://www.journals.uchicago.edu/doi/suppl/10.1086/712930.-- Data and Code Availability: All raw data and referenced supplemental files in this article have been deposited in the Dryad Digital Repository (https://doi.org/10.5061/dryad.tqjq2bvxc; Bitter et al. 2020). All code associated with statistical analyses and figure generation for this article are publicly available at GitHub (https://github.com/MarkCBitter/pHFluctuation_Plasticity) and Zenodo (https://doi.org/10.5281/zenodo.4306829; Bitter 2020) Phenotypic plasticity is expected to facilitate the persistence of natural populations as global change progresses. The attributes of fluctuating environments that favor the evolution of plasticity have received extensive theoretical investigation, yet empirical validation of these findings is still in its infancy. Here, we combine high-resolution environmental data with a laboratory-based experiment to explore the influence of habitat pH fluctuation dynamics on the plasticity of gene expression in two populations of the Mediterranean mussel, Mytilus galloprovincialis. We linked differences in the magnitude and predictability of pH fluctuations in two habitats to population-specific gene expression profiles in ambient and stressful pH treatments. Our results demonstrate population-based differentiation in gene expression plasticity, whereby mussels native to a habitat exhibiting a large magnitude of pH fluctuations with low predictability display reduced phenotypic plasticity between experimentally imposed pH treatments. This work validates recent theoretical findings on evolution in fluctuating environments, suggesting that the predictability of fluctuating selection pressures may play a predominant role in shaping the phenotypic variation observed across natural populations M.C.B. was supported by a National Science Foundation Graduate Research Fellowship Program grant (1746045) and a Department of Education grant (P200A150101). L.K. was supported by a National ...