Brett's hypothesis[1][2] also known as the heat-invariant hypothesis[3][4] or Brett's heat-invariant hypothesis[5] proposes that upper thermal tolerance limits are less variable geographically than lower thermal tolerance limits. This hypothesis was originally proposed for fish[1] but lately has been supported by studies with reptiles,[6] amphibians,[5] and aquatic insects.[7] Three different mechanisms are proposed for the existence of this large-scale pattern of thermal tolerance limits variation:
- A constrained evolutionary potential of upper thermal tolerance limits
- The buffering effects of thermoregulatory behaviour has greater potential to face heat rather than cold stress
- Resolution of thermal data used
Global versus local scales in Brett's hypothesis edit
While Brett's hypothesis has been strongly supported at global scales, heat tolerance seems to respond differently to smaller-scale climatic and habitat factors. For instance, lizards from the Iberian Peninsula[8] show higher variation in upper thermal tolerance limits than in lower thermal tolerance limits. Similar results are found in adult frogs,[5] tadpoles, and dragonfly larvae[7] at local scales.
References edit
- ^ a b Brett, J. R. (June 1956). "Some Principles in the Thermal Requirements of Fishes". The Quarterly Review of Biology. 31 (2): 75–87. doi:10.1086/401257. S2CID 84155127 – via The University of Chicago Press Journals.
- ^ Gaston, Kevin J.; Chown, Steven L.; Calosi, Piero; Bernardo, Joseph; Bilton, David T.; Clarke, Andrew; Clusella-Trullas, Susana; Ghalambor, Cameron K.; Konarzewski, Marek; Peck, Lloyd S.; Porter, Warren P.; Pörtner, Hans O.; Rezende, Enrico L.; Schulte, Patricia M.; Spicer, John I.; Stillman, Jonathon H.; Terblanche, John S.; van Kleunen, Mark (November 2009). McPeek, Mark A. (ed.). "Macrophysiology: A Conceptual Reunification". The American Naturalist. 174 (5): 595–612. doi:10.1086/605982. hdl:10019.1/119921. PMID 19788354. S2CID 6239591 – via The University of Chicago Press Journals.
- ^ Araújo, Miguel B.; Ferri-Yáñez, Francisco; Bozinovic, Francisco; Marquet, Pablo A.; Valladares, Fernando; Chown, Steven L. (September 2013). "Heat freezes niche evolution". Ecology Letters. 16 (9): 1206–1219. doi:10.1111/ele.12155. hdl:10261/125474. ISSN 1461-0248. PMID 23869696.
- ^ Bozinovic, Francisco; Orellana, María J. M.; Martel, Sebastián I.; Bogdanovich, José M. (December 2014). "Testing the heat-invariant and cold-variability tolerance hypotheses across geographic gradients". Comparative Biochemistry and Physiology A. 178: 46–50. doi:10.1016/j.cbpa.2014.08.009. PMID 25152532.
- ^ a b c Pintanel, Pol; Tejedo, Miguel; Ron, Santiago R.; Llorente, Gustavo A.; Merino-Viteri, Andrés (July 24, 2019). "Elevational and microclimatic drivers of thermal tolerance in Andean Pristimantis frogs". Journal of Biogeography. 46 (8): 1664–1675. doi:10.1111/jbi.13596. S2CID 181476379.
- ^ Muñoz, Martha M.; Stimola, Maureen A.; Algar, Adam C.; Conover, Asa; Rodriguez, Anthony J.; Landestoy, Miguel A.; Bakken, George S.; Losos, Jonathan B. (January 15, 2014). "Evolutionary stasis and lability in thermal physiology in a group of tropical lizards". Proceedings of the Royal Society B. 281 (1778). doi:10.1098/rspb.2013.2433. eISSN 1471-2954. ISSN 0962-8452. PMC 3906933. PMID 24430845 – via The Royal Society.
- ^ a b Pintanel, Pol; Tejedo, Miguel; Salinas-Ivanenko, Sofia; Jervis, Phillip; Merino-Viteri, Andrés (August 2021). "Predators like it hot: Thermal mismatch in a predator-prey system across an elevational tropical gradient". Journal of Animal Ecology. 90 (8): 1985–1995. doi:10.1111/1365-2656.13516. PMID 33942306. S2CID 233720734.
- ^ Herrando-Pérez, Salvador; Monasterio, Camila; Beukema, Wouter; Gomes, Verónica; Ferri-Yáñez, Francisco; Vieites, David R.; Buckley, Lauren B.; Araújo, Miguel B. (December 10, 2019). "Heat tolerance is more variable than cold tolerance across species of Iberian lizards after controlling for intraspecific variation". Functional Ecology. 34 (3): 631–645. doi:10.1111/1365-2435.13507. hdl:10174/34934. S2CID 214359887.