Projecting ecological and evolutionary responses to variable and changing environments is
central to anticipating and managing impacts to biodiversity and ecosystems. Current model-
ing approaches are largely phenomenological and often fail to accurately project responses
due to numerous biological processes at multiple levels of biological organization responding
to environmental variation at varied spatial and temporal scales. Limited mechanistic under-
standing of organismal responses to environmental variability and extremes also restricts
predictive capacity. We outline a strategy for identifying and modeling the key organismal
mechanisms across levels of biological organization that mediate ecological and evolutionary
responses to environmental variation. A central component of this strategy is quantifying
timescales and magnitudes of climatic variability and how organisms experience them. We
highlight recent empirical research that builds this information and suggest how to design
future experiments that can produce more generalizable principles. We discuss how to create
biologically informed projections in a feasible way by combining statistical and mechanistic
approaches. Predictions will inform both fundamental and practical questions at the interface
of ecology, evolution, and Earth science such as how organisms experience, adapt to, and
respond to environmental variation at multiple hierarchical spatial and temporal scales.
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Microbial evolutionary strategies in a dynamic ocean
Marine microbes form the base of ocean food webs and drive ocean biogeochemical cycling. Yet little is known about the ability of microbial populations to adapt as they are advected through changing conditions. Here, we investigated the interplay between physical and biological timescales using a model of adaptation and an eddy-resolving ocean circulation climate model. Two criteria were identified that relate the timing and nature of adaptation to the ratio of physical to biological timescales. Genetic adaptation was impeded in highly variable regimes by nongenetic modifications but was promoted in more stable environments. An evolutionary trade-off emerged where greater short-term nongenetic transgenerational effects (low-γ strategy) enabled rapid responses to environmental fluctuations but delayed genetic adaptation, while fewer short-term transgenerational effects (high-γ strategy) allowed faster genetic adaptation but inhibited short-term responses. Our results demonstrate that the selective pressures for organisms within a single water mass vary based on differences in generation timescales resulting in different evolutionary strategies being favored. Organisms that experience more variable environments should favor a low-γ strategy. Furthermore, faster cell division rates should be a key factor in genetic adaptation in a changing ocean. Understanding and quantifying the relationship between evolutionary and physical timescales is critical for robust predictions of future microbial dynamics.
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- Award ID(s):
- 1538525
- NSF-PAR ID:
- 10145914
- Date Published:
- Journal Name:
- Proceedings of the National Academy of Sciences
- Volume:
- 117
- Issue:
- 11
- ISSN:
- 0027-8424
- Page Range / eLocation ID:
- 5943 to 5948
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1073/pnas.1919332117
