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Selmoni O, Bay LK, Exposito-Alonso M, Cleves PA. Finding genes and pathways that underlie coral adaptation. Trends Genet 2024; 40:213-227. [PMID: 38320882 DOI: 10.1016/j.tig.2024.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 02/08/2024]
Abstract
Mass coral bleaching is one of the clearest threats of climate change to the persistence of marine biodiversity. Despite the negative impacts of bleaching on coral health and survival, some corals may be able to rapidly adapt to warming ocean temperatures. Thus, a significant focus in coral research is identifying the genes and pathways underlying coral heat adaptation. Here, we review state-of-the-art methods that may enable the discovery of heat-adaptive loci in corals and identify four main knowledge gaps. To fill these gaps, we describe an experimental approach combining seascape genomics with CRISPR/Cas9 gene editing to discover and validate heat-adaptive loci. Finally, we discuss how information on adaptive genotypes could be used in coral reef conservation and management strategies.
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Affiliation(s)
- Oliver Selmoni
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA; Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.
| | - Line K Bay
- Reef Recovery, Adaptation, and Restoration, Australian Institute of Marine Science; Townsville, QLD 4810, Australia
| | - Moises Exposito-Alonso
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA; Department of Biology, Stanford University, Stanford, CA 94305, USA; Department of Global Ecology, Carnegie Institution for Science, Stanford, CA 94305, USA.
| | - Phillip A Cleves
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA; Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA.
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2
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Quigley KM. Breeding and Selecting Corals Resilient to Global Warming. Annu Rev Anim Biosci 2024; 12:209-332. [PMID: 37931139 DOI: 10.1146/annurev-animal-021122-093315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023]
Abstract
Selective breeding of resilient organisms is an emerging topic in marine conservation. It can help us predict how species will adapt in the future and how we can help restore struggling populations effectively in the present. Scleractinian corals represent a potential tractable model system given their widescale phenotypic plasticity across fitness-related traits and a reproductive life history based on mass synchronized spawning. Here, I explore the justification for breeding in corals, identify underutilized pathways of acclimation, and highlight avenues for quantitative targeted breeding from the coral host and symbiont perspective. Specifically, the facilitation of enhanced heat tolerance by targeted breeding of plasticity mechanisms is underutilized. Evidence from theoretical genetics identifies potential pitfalls, including inattention to physical and genetic characteristics of the receiving environment. Three criteria for breeding emerge from this synthesis: selection from warm, variable reefs that have survived disturbance. This information will be essential to protect what we have and restore what we can.
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Affiliation(s)
- K M Quigley
- The Minderoo Foundation, Perth, Western Australia, Australia;
- James Cook University, Townsville, Queensland, Australia
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3
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Brown KT, Lenz EA, Glass BH, Kruse E, McClintock R, Drury C, Nelson CE, Putnam HM, Barott KL. Divergent bleaching and recovery trajectories in reef-building corals following a decade of successive marine heatwaves. Proc Natl Acad Sci U S A 2023; 120:e2312104120. [PMID: 38113265 PMCID: PMC10756270 DOI: 10.1073/pnas.2312104120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 11/17/2023] [Indexed: 12/21/2023] Open
Abstract
Increasingly frequent marine heatwaves are devastating coral reefs. Corals that survive these extreme events must rapidly recover if they are to withstand subsequent events, and long-term survival in the face of rising ocean temperatures may hinge on recovery capacity and acclimatory gains in heat tolerance over an individual's lifespan. To better understand coral recovery trajectories in the face of successive marine heatwaves, we monitored the responses of bleaching-susceptible and bleaching-resistant individuals of two dominant coral species in Hawai'i, Montipora capitata and Porites compressa, over a decade that included three marine heatwaves. Bleaching-susceptible colonies of P. compressa exhibited beneficial acclimatization to heat stress (i.e., less bleaching) following repeat heatwaves, becoming indistinguishable from bleaching-resistant conspecifics during the third heatwave. In contrast, bleaching-susceptible M. capitata repeatedly bleached during all successive heatwaves and exhibited seasonal bleaching and substantial mortality for up to 3 y following the third heatwave. Encouragingly, bleaching-resistant individuals of both species remained pigmented across the entire time series; however, pigmentation did not necessarily indicate physiological resilience. Specifically, M. capitata displayed incremental yet only partial recovery of symbiont density and tissue biomass across both bleaching phenotypes up to 35 mo following the third heatwave as well as considerable partial mortality. Conversely, P. compressa appeared to recover across most physiological metrics within 2 y and experienced little to no mortality. Ultimately, these results indicate that even some visually robust, bleaching-resistant corals can carry the cost of recurring heatwaves over multiple years, leading to divergent recovery trajectories that may erode coral reef resilience in the Anthropocene.
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Affiliation(s)
- Kristen T. Brown
- Department of Biology, University of Pennsylvania, Philadelphia, PA19104
| | - Elizabeth A. Lenz
- University of Hawai’i Sea Grant College Program, University of Hawai’i at Mānoa, Honolulu, HI96822
| | - Benjamin H. Glass
- Department of Biology, University of Pennsylvania, Philadelphia, PA19104
| | - Elisa Kruse
- Department of Biology, University of Pennsylvania, Philadelphia, PA19104
| | - Rayna McClintock
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography, University of Hawai’i at Mānoa, Honolulu, HI96822
| | - Crawford Drury
- Hawai’i Institute of Marine Biology, University of Hawai’i at Mānoa, Kāne‘ohe, HI96744
| | - Craig E. Nelson
- University of Hawai’i Sea Grant College Program, University of Hawai’i at Mānoa, Honolulu, HI96822
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, Department of Oceanography, University of Hawai’i at Mānoa, Honolulu, HI96822
| | - Hollie M. Putnam
- Department of Biological Sciences, University of Rhode Island, Kingston, RI02881
| | - Katie L. Barott
- Department of Biology, University of Pennsylvania, Philadelphia, PA19104
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4
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Prioux C, Tignat-Perrier R, Gervais O, Estaque T, Schull Q, Reynaud S, Béraud E, Mérigot B, Beauvieux A, Marcus MI, Richaume J, Bianchimani O, Cheminée A, Allemand D, Ferrier-Pagès C. Unveiling microbiome changes in Mediterranean octocorals during the 2022 marine heatwaves: quantifying key bacterial symbionts and potential pathogens. MICROBIOME 2023; 11:271. [PMID: 38053218 PMCID: PMC10696765 DOI: 10.1186/s40168-023-01711-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 10/27/2023] [Indexed: 12/07/2023]
Abstract
BACKGROUND Climate change has accelerated the occurrence and severity of heatwaves in the Mediterranean Sea and poses a significant threat to the octocoral species that form the foundation of marine animal forests (MAFs). As coral health intricately relies on the symbiotic relationships established between corals and microbial communities, our goal was to gain a deeper understanding of the role of bacteria in the observed tissue loss of key octocoral species following the unprecedented heatwaves in 2022. RESULTS Using amplicon sequencing and taxon-specific qPCR analyses, we unexpectedly found that the absolute abundance of the major bacterial symbionts, Spirochaetaceae (C. rubrum) and Endozoicomonas (P. clavata), remained, in most cases, unchanged between colonies with 0% and 90% tissue loss. These results suggest that the impairment of coral health was not due to the loss of the main bacterial symbionts. However, we observed a significant increase in the total abundance of bacterial opportunists, including putative pathogens such as Vibrio, which was not evident when only their relative abundance was considered. In addition, there was no clear relation between bacterial symbiont loss and the intensity of thermal stress, suggesting that factors other than temperature may have influenced the differential response of octocoral microbiomes at different sampling sites. CONCLUSIONS Our results indicate that tissue loss in octocorals is not directly caused by the decline of the main bacterial symbionts but by the proliferation of opportunistic and pathogenic bacteria. Our findings thus underscore the significance of considering both relative and absolute quantification approaches when evaluating the impact of stressors on coral microbiome as the relative quantification does not accurately depict the actual changes in the microbiome. Consequently, this research enhances our comprehension of the intricate interplay between host organisms, their microbiomes, and environmental stressors, while offering valuable insights into the ecological implications of heatwaves on marine animal forests. Video Abstract.
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Affiliation(s)
- Camille Prioux
- Collège Doctoral, Sorbonne Université, Paris, France
- Unité de Recherche sur la Biologie des Coraux Précieux CSM - CHANEL, Centre Scientifique de Monaco, 8 Quai Antoine 1er, Monaco, MC-98000 Monaco, Principality of Monaco
- Centre Scientifique de Monaco, 8 Quai Antoine 1er, Monaco, MC 98000, Principality of Monaco
| | - Romie Tignat-Perrier
- Unité de Recherche sur la Biologie des Coraux Précieux CSM - CHANEL, Centre Scientifique de Monaco, 8 Quai Antoine 1er, Monaco, MC-98000 Monaco, Principality of Monaco
- Centre Scientifique de Monaco, 8 Quai Antoine 1er, Monaco, MC 98000, Principality of Monaco
| | - Ophélie Gervais
- Unité de Recherche sur la Biologie des Coraux Précieux CSM - CHANEL, Centre Scientifique de Monaco, 8 Quai Antoine 1er, Monaco, MC-98000 Monaco, Principality of Monaco
- Centre Scientifique de Monaco, 8 Quai Antoine 1er, Monaco, MC 98000, Principality of Monaco
| | - Tristan Estaque
- Septentrion Environnement, Campus Nature Provence, Marseille, 13008, France
| | - Quentin Schull
- MARBEC, Univ. Montpellier, CNRS, IFREMER, IRD, Sète, France
| | - Stéphanie Reynaud
- Centre Scientifique de Monaco, 8 Quai Antoine 1er, Monaco, MC 98000, Principality of Monaco
| | - Eric Béraud
- Centre Scientifique de Monaco, 8 Quai Antoine 1er, Monaco, MC 98000, Principality of Monaco
| | | | | | - Maria-Isabelle Marcus
- Centre Scientifique de Monaco, 8 Quai Antoine 1er, Monaco, MC 98000, Principality of Monaco
| | - Justine Richaume
- Septentrion Environnement, Campus Nature Provence, Marseille, 13008, France
| | | | - Adrien Cheminée
- Septentrion Environnement, Campus Nature Provence, Marseille, 13008, France
| | - Denis Allemand
- Centre Scientifique de Monaco, 8 Quai Antoine 1er, Monaco, MC 98000, Principality of Monaco
| | - Christine Ferrier-Pagès
- Centre Scientifique de Monaco, 8 Quai Antoine 1er, Monaco, MC 98000, Principality of Monaco.
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Glass BH, Jones KG, Ye AC, Dworetzky AG, Barott KL. Acute heat priming promotes short-term climate resilience of early life stages in a model sea anemone. PeerJ 2023; 11:e16574. [PMID: 38077426 PMCID: PMC10704996 DOI: 10.7717/peerj.16574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 11/13/2023] [Indexed: 12/18/2023] Open
Abstract
Across diverse taxa, sublethal exposure to abiotic stressors early in life can lead to benefits such as increased stress tolerance upon repeat exposure. This phenomenon, known as hormetic priming, is largely unexplored in early life stages of marine invertebrates, which are increasingly threatened by anthropogenic climate change. To investigate this phenomenon, larvae of the sea anemone and model marine invertebrate Nematostella vectensis were exposed to control (18 °C) or elevated (24 °C, 30 °C, 35 °C, or 39 °C) temperatures for 1 h at 3 days post-fertilization (DPF), followed by return to control temperatures (18 °C). The animals were then assessed for growth, development, metabolic rates, and heat tolerance at 4, 7, and 11 DPF. Priming at intermediately elevated temperatures (24 °C, 30 °C, or 35 °C) augmented growth and development compared to controls or priming at 39 °C. Indeed, priming at 39 °C hampered developmental progression, with around 40% of larvae still in the planula stage at 11 DPF, in contrast to 0% for all other groups. Total protein content, a proxy for biomass, and respiration rates were not significantly affected by priming, suggesting metabolic resilience. Heat tolerance was quantified with acute heat stress exposures, and was significantly higher for animals primed at intermediate temperatures (24 °C, 30 °C, or 35 °C) compared to controls or those primed at 39 °C at all time points. To investigate a possible molecular mechanism for the observed changes in heat tolerance, the expression of heat shock protein 70 (HSP70) was quantified at 11 DPF. Expression of HSP70 significantly increased with increasing priming temperature, with the presence of a doublet band for larvae primed at 39 °C, suggesting persistent negative effects of priming on protein homeostasis. Interestingly, primed larvae in a second cohort cultured to 6 weeks post-fertilization continued to display hormetic growth responses, whereas benefits for heat tolerance were lost; in contrast, negative effects of short-term exposure to extreme heat stress (39 °C) persisted. These results demonstrate that some dose-dependent effects of priming waned over time while others persisted, resulting in heterogeneity in organismal performance across ontogeny following priming. Overall, these findings suggest that heat priming may augment the climate resilience of marine invertebrate early life stages via the modulation of key developmental and physiological phenotypes, while also affirming the need to limit further anthropogenic ocean warming.
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Affiliation(s)
- Benjamin H. Glass
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Katelyn G. Jones
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Angela C. Ye
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Anna G. Dworetzky
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Katie L. Barott
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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Brown KT, Genin A, Mello‐Athayde MA, Bergstrom E, Campili A, Chai A, Dove SG, Ho M, Rowell D, Sampayo EM, Radice VZ. Marine heatwaves modulate the genotypic and physiological responses of reef-building corals to subsequent heat stress. Ecol Evol 2023; 13:e10798. [PMID: 38099138 PMCID: PMC10719612 DOI: 10.1002/ece3.10798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 11/21/2023] [Indexed: 12/17/2023] Open
Abstract
Back-to-back marine heatwaves in 2016 and 2017 resulted in severe coral bleaching and mortality across the Great Barrier Reef (GBR). Encouragingly, some corals that survived these events exhibit increased bleaching resistance and may represent thermally tolerant populations that can better cope with ocean warming. Using the GBR as a natural laboratory, we investigated whether a history of minimal (Heron Island) or severe (Lizard Island) coral bleaching in 2016 and 2017 equates to stress tolerance in a successive heatwave (2020). We examined the genetic diversity, physiological performance, and trophic plasticity of juvenile (<10 cm) and adult (>25 cm) corals of two common genera (Pocillopora and Stylophora). Despite enduring greater cumulative heat stress (6.3°C week-1 vs. 5.6°C week-1), corals that experienced the third marine heatwave in 5 years (Lizard) exhibited twice as high survival and visual bleaching thresholds compared to corals that had not experienced significant bleaching in >10 years (Heron). Surprisingly, only one shared host-Symbiodiniaceae association was uncovered between locations (Stylophora pistillata-Cladocopium "C8 group") and there was no genetic overlap in Pocillopora-Cladocopium partnerships, suggesting turnover in species composition from recent marine heatwaves. Corals within the species complex Pocillopora that survived the 2016 and 2017 marine heatwaves at Lizard Island were the most resilient, exhibiting three times greater calcification rates than conspecifics at Heron Island. Further, surviving corals (Lizard) had distinct isotopic niches, lower host carbon, and greater host protein, while conspecifics that had not experienced recent bleaching (Heron) had two times greater symbiont carbon content, suggesting divergent trophic strategies that influenced survival (i.e., greater reliance on heterotrophy vs. symbiont autotrophy, respectively). Ultimately, while corals may experience less bleaching and survive repeated thermal stress events, species-specific trade-offs do occur, leaving open many questions related to the long-term health and recovery of coral reef ecosystems in the face of intensifying marine heatwaves.
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Affiliation(s)
- Kristen T. Brown
- School of Biological SciencesUniversity of QueenslandSt LuciaQueenslandAustralia
- Department of BiologyUniversity of PennsylvaniaPhiladelphiaPennsylvaniaUSA
| | - Amatzia Genin
- The Interuniversity Institute for Marine Sciences of EilatThe Hebrew University of JerusalemEilatIsrael
| | | | | | - Adriana Campili
- Australian Institute of Marine ScienceTownsville Mail CentreTownsvilleQueenslandAustralia
| | - Aaron Chai
- Faculty of Science and EngineeringSouthern Cross UniversityEast LismoreNew South WalesAustralia
| | - Sophie G. Dove
- School of Biological SciencesUniversity of QueenslandSt LuciaQueenslandAustralia
| | | | - Devin Rowell
- School of Biological SciencesUniversity of QueenslandSt LuciaQueenslandAustralia
| | - Eugenia M. Sampayo
- School of Biological SciencesUniversity of QueenslandSt LuciaQueenslandAustralia
| | - Veronica Z. Radice
- School of Biological SciencesUniversity of QueenslandSt LuciaQueenslandAustralia
- Department of Biological SciencesOld Dominion UniversityNorfolkVirginiaUSA
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Byrne M, Deaker DJ, Gibbs M, Selvakumaraswamy P, Clements M. Juvenile waiting stage crown-of-thorns sea stars are resilient in heatwave conditions that bleach and kill corals. GLOBAL CHANGE BIOLOGY 2023; 29:6493-6502. [PMID: 37849435 DOI: 10.1111/gcb.16946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 07/30/2023] [Accepted: 08/27/2023] [Indexed: 10/19/2023]
Abstract
The juveniles of predatory sea stars can remain in their recruitment-nursery habitat for some time before their ontogenetic shift to the adult habitat and diet. These small juveniles are vulnerable to a range of factors with their sensitivity amplified by climate change-driven ocean warming. We investigate the thermal tolerance of the waiting stage herbivorous juveniles of the keystone coral predator, the crown-of-thorns sea star (COTS, Acanthaster sp.), in context with the degree heating weeks (DHW) model that predicts coral bleaching and mass mortality. In temperature treatments ranging from +1 to 3°C in prolonged heatwave acclimation conditions, the juveniles exhibited ~100% survival in DHW scenarios that trigger coral bleaching (4 DHW), resulting in mass mortality of corals (8 DHW) and extreme conditions well beyond those that kill corals (12 DHW). This indicates that herbivorous juvenile COTS are far more resistant to heatwave conditions than the coral prey of the adults. The juveniles exhibited higher activity (righting) and metabolic rate after weeks in increased temperature. In separate acute temperature experiments, the upper thermal limit of the juveniles was 34-36°C. In a warming world, juvenile COTS residing in their coral rubble nursery habitat will benefit from an increase in the extent of this habitat due to coral mortality. The juveniles have potential for long-term persistence as herbivores as they wait for live coral to recover before becoming coral predators, thereby serving as a proximate source of COTS outbreaks on reefs already in a tenuous state due to climate change.
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Affiliation(s)
- Maria Byrne
- School of Life and Environmental Sciences and Marine Studies Institute, The University Sydney, Sydney, New South Wales, Australia
| | - Dione J Deaker
- School of Life and Environmental Sciences and Marine Studies Institute, The University Sydney, Sydney, New South Wales, Australia
| | - Mitchell Gibbs
- School of Life and Environmental Sciences and Marine Studies Institute, The University Sydney, Sydney, New South Wales, Australia
| | - Paulina Selvakumaraswamy
- School of Life and Environmental Sciences and Marine Studies Institute, The University Sydney, Sydney, New South Wales, Australia
| | - Matthew Clements
- School of Life and Environmental Sciences and Marine Studies Institute, The University Sydney, Sydney, New South Wales, Australia
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Dellaert Z, Putnam HM. Reconciling the variability in the biological response of marine invertebrates to climate change. J Exp Biol 2023; 226:jeb245834. [PMID: 37655544 DOI: 10.1242/jeb.245834] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
As climate change increases the rate of environmental change and the frequency and intensity of disturbance events, selective forces intensify. However, given the complicated interplay between plasticity and selection for ecological - and thus evolutionary - outcomes, understanding the proximate signals, molecular mechanisms and the role of environmental history becomes increasingly critical for eco-evolutionary forecasting. To enhance the accuracy of our forecasting, we must characterize environmental signals at a level of resolution that is relevant to the organism, such as the microhabitat it inhabits and its intracellular conditions, while also quantifying the biological responses to these signals in the appropriate cells and tissues. In this Commentary, we provide historical context to some of the long-standing challenges in global change biology that constrain our capacity for eco-evolutionary forecasting using reef-building corals as a focal model. We then describe examples of mismatches between the scales of external signals relative to the sensors and signal transduction cascades that initiate and maintain cellular responses. Studying cellular responses at this scale is crucial because these responses are the basis of acclimation to changing environmental conditions and the potential for environmental 'memory' of prior or historical conditions through molecular mechanisms. To challenge the field, we outline some unresolved questions and suggest approaches to align experimental work with an organism's perception of the environment; these aspects are discussed with respect to human interventions.
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Affiliation(s)
- Zoe Dellaert
- Department of Biological Sciences, University of Rhode Island, 120 Flagg Rd, Kingston, RI 02881, USA
| | - Hollie M Putnam
- Department of Biological Sciences, University of Rhode Island, 120 Flagg Rd, Kingston, RI 02881, USA
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