Browsing by Author "Santos, Mauro"

Now showing 1 - 7 of 7
  • No Thumbnail Available
    Item
    Climate change and chromosomal inversions in Drosophila subobscura
    (2010) Rezende Landaeta, Enrico; Balanyá, Joan; Fragata, Ines; Matos, Margarida; Rego, Carla; Rodriguez-Trelles, Francisco; Santos, Mauro; Serra, Luis
  • Thumbnail Image
    Item
    Genetic constraints for thermal coadaptation in Drosophila subobscura
    (2010) Dolgova, Olga; Rego, Carla; Calabria, Gema; Balanya, Joan; Pascual, Marta; Rezende Landaeta, Enrico; Santos, Mauro
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    Intraspecific variation of heat tolerance in a model ectotherm: The role of oxygen, cell size and body size
    (2023) Leiva, Félix P.; Santos, Mauro; Rezende Landaeta, Enrico; Verberk, Wilco C. E. P.
    Virtually all aspects of the biology of ectotherms are size-and temperature-dependent. Aerobic metabolism is often proposed to explain such relationships, with oxygen limitation setting limits to heat tolerance and constraining growth. However, experimental tests of the role of oxygen in heat tolerance have yielded mixed results, suggesting that oxygen limitation may be important only in certain contexts and on certain time scales but not others. Here, using thermal death time curves, which incorporate the intensity and duration of heat stress, we quantify the ability to survive heat stress in multiple inbred lines of Drosophila melanogaster, under normal and low oxygen conditions. The lines were selected to differ markedly in body size and cell size, as these traits have been hypothesised to shape thermal tolerance via their effects on oxygen supply and demand. Low oxygen condition markedly reduced survival time across inbred lines, especially when flies were exposed to prolonged, mild heat stress. Variations in heat tolerance among lines were partly related to cell size and body size differences, especially under chronic exposure to high temperatures, under hypoxia and in flies that exhibit larger cell size, supporting the idea that differences in cell size affect the oxygen supply and demand via differences in surface area to volume ratio. Because differences in heat tolerance were manifested at different timescales, our results underscore the need to close the gap between responses to acute timescales, typically employed in laboratory studies, and chronic timescales, which are ecologically more relevant.
  • Thumbnail Image
    Item
    Making sense of heat tolerance estimates in ectotherms: Lessons from Drosophila
    (2011) Santos, Mauro; Castañeda, Luis E.; Rezende Landaeta, Enrico
  • No Thumbnail Available
    Item
    Temperature adaptation and its impact on the shape of performance curves in Drosophila populations
    (2023) Alruiz, Jose M.; Peralta-Maraver, Ignacio; Bozinovic, Francisco; Santos, Mauro; Rezende, Enrico L.
    Understanding how species adapt to different temperatures is crucial to predict their response to global warming, and thermal performance curves (TPCs) have been employed recurrently to study this topic. Nevertheless, fundamental questions regarding how thermodynamic constraints and evolution interact to shape TPCs in lineages inhabiting different environments remain unanswered. Here, we study Drosophila simulans along a latitudinal gradient spanning 3000 km to test opposing hypotheses based on thermodynamic constrains (hotter-is-better) versus biochemical adaptation (jack-of-all-temperatures) as primary determinants of TPCs variation across populations. We compare thermal responses in metabolic rate and the egg-to-adult survival as descriptors of organismal performance and fitness, respectively, and show that different descriptors of TPCs vary in tandem with mean environmental temperatures, providing strong support to hotter-is-better. Thermodynamic constraints also resulted in a strong negative association between maximum performance and thermal breadth. Lastly, we show that descriptors of TPCs for metabolism and egg-to-adult survival are highly correlated, providing evidence of co-adaptation, and that curves for egg-to-adult survival are systematically narrower and displaced toward lower temperatures. Taken together, our results support the pervasive role of thermodynamics constraining thermal responses in Drosophila populations along a latitudinal gradient, that are only partly compensated by evolutionary adaptation.
  • Thumbnail Image
    Item
    Thermal tolerance in Drosophila : Repercussions for distribution, community coexistence and responses to climate change
    (2022) Alruiz, José M. ; Peralta‐Maraver, Ignacio ; Bozinovic, Francisco ; Santos, Mauro ; Enrico L. Rezende
    Here we combined controlled experiments and field surveys to determine if estimates of heat tolerance predict distributional ranges and phenology of different Drosophila species in southern South America. We contrasted thermal death time curves, which consider both magnitude and duration of the challenge to estimate heat tolerance, against the thermal range where populations are viable based on field surveys in an 8-year longitudinal study. We observed a strong correspondence of the physiological limits, the thermal niche for population growth, and the geographic ranges across studied species, which suggests that the thermal biology of different species provides a common currency to understand how species will respond to warming temperatures both at a local level and throughout their distribution range. Our approach represents a novel analytical toolbox to anticipate how natural communities of ectothermic organisms will respond to global warming.