bioRxiv preprint doi: https://doi.org/10.1101/2020.12.26.424431; this version posted December 27, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 Elevational gradients do not affect thermal tolerance at local scale in 2 populations of livebearing fishes of the genus Limia (Teleostei, Poeciliidae) 3 4 Rodet Rodriguez Silva1 and Ingo Schlupp1 5 1Department of Biology, University of Oklahoma, 730 Van Vleet Oval, Norman, OK 6 73019. 7 8 Correspondence: 9 Rodet Rodriguez Silva, Department of Biology, University of Oklahoma, 730 Van Vleet 10 Oval, Norman, OK 73019 11 Email:
[email protected] 12 13 Funding information: 14 This study was supported by the National Geographic Society (WW-054R-17) and the 15 University of Oklahoma. 16 17 Abstract 18 One of the main assumptions of Janzen’s (1976) mountain passes hypothesis is that due 19 the low overlap in temperature regimes between low and high elevations in the tropics, 20 organisms living in high-altitude evolve narrow tolerance for colder temperatures while 21 low-altitude species develop narrow tolerance for warmer temperatures. Some studies 22 have questioned the generality of the assumptions and predictions of this hypothesis 23 suggesting that other factors different to temperature gradients between low and high 1 bioRxiv preprint doi: https://doi.org/10.1101/2020.12.26.424431; this version posted December 27, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder.