Biophysical modeling of water economy can explain geographic gradient of body size in Anurans
Nenhuma Miniatura disponível
Data
2019
Título da Revista
ISSN da Revista
Título de Volume
Editor
Resumo
Geographical gradients of body size express climate-driven
constraints on animals, but whether they exist and what causes them
in ectotherms remains contentious. For amphibians, the water conser vation hypothesis posits that larger bodies reduce evaporative water
loss (EWL) along dehydrating gradients. To address this hypothesis
mechanistically, we build on well-established biophysical equations
of water exchange in anurans to propose a state-transition model that
predicts an increase of either body size or resistance to EWL as alter native specialization along dehydrating gradients. The model predicts
that species whose water economy is more sensitive to variation in
body size than to variation in resistance to EWL should increase in
size in response to increasing potential evapotranspiration (PET).
To evaluate the model predictions, we combine physiological measure ments of resistance to EWL with geographic data of body size for four
different anuran species. Only one species, Dendropsophus minutus,
was predicted to exhibit a positive body size–PET relationship. Results
were as predicted for all cases, with one species—Boana faber—show ing a negative relationship. Based on an empirically verified mathemat ical model, we show that clines of body size among anurans depend on
the current values of those traits and emerge as an advantage for water
conservation. Our model offers a mechanistic and compelling explana tion for the cause and variation of gradients of body size in anurans.
Descrição
Palavras-chave
Allometry, Water conservation hypothesis, Biophysical model, Macrophysiology, Ectotherms, Evaporative water loss
Citação
GOUVEIA, Sidney F. et al. Biophysical modeling of water economy can explain geographic gradient of body size in Anurans. American Naturalist, Chicago, v. 193, n. 1, p. 51-58, 2019. DOI: 10.1086/700833. Disponível em: https://www.journals.uchicago.edu/doi/10.1086/700833. Acesso em: 21 jul. 2023.