Thermal melanism explains macroevolutionary variation of dorsal pigmentation in Eurasian vipers
Abstract Colouration may endorse thermoregulatory and antipredatory functions in snakes. The thermal melanism hypothesis predicts that dark-coloured individuals are ecologically favoured in cool climates. However, the loss of aposematic and cryptic colourations may imply high predation for melanisti...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2020-09-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-020-72871-1 |
| _version_ | 1818572999191691264 |
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| author | Fernando Martínez-Freiría Ken S. Toyama Inês Freitas Antigoni Kaliontzopoulou |
| author_facet | Fernando Martínez-Freiría Ken S. Toyama Inês Freitas Antigoni Kaliontzopoulou |
| author_sort | Fernando Martínez-Freiría |
| collection | DOAJ |
| description | Abstract Colouration may endorse thermoregulatory and antipredatory functions in snakes. The thermal melanism hypothesis predicts that dark-coloured individuals are ecologically favoured in cool climates. However, the loss of aposematic and cryptic colourations may imply high predation for melanistic snakes. Here, we used the monophyletic group of Eurasian vipers (subfamily Viperinae) to test whether an increase in the extent of dark area inside the characteristic zigzag dorsal pattern is associated to colder environments. We measured two colouration traits in zigzag-patterned individuals (number of dorsal marks and weighted pigmentation index) and used a phylogenetic comparative approach to explore macroevolutionary patterns of dorsal pigmentation and test whether its extent is associated to ecogeographic characteristics of lineages’ ranges. Phylogenetically-naïve and phylogenetically-informed analyses yielded a significant association between the degree of pigmentation of the zigzag pattern and environmental variables such as solar radiation, elevation and latitude. The degree of pigmentation of the zigzag pattern is highlighted as an adaptive trait that matches range attributes mirroring cold environments irrespective of the phylogeny. These results constitute the first large-scale evidence supporting the thermal melanism hypothesis in snakes, opening new avenues of inquiry for the mechanisms that shape the evolution of colour phenotypes. |
| first_indexed | 2024-12-15T00:05:14Z |
| format | Article |
| id | doaj.art-f0a24b2822c145fc8811880ca1501b3f |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-12-15T00:05:14Z |
| publishDate | 2020-09-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-f0a24b2822c145fc8811880ca1501b3f2022-12-21T22:42:45ZengNature PortfolioScientific Reports2045-23222020-09-0110111010.1038/s41598-020-72871-1Thermal melanism explains macroevolutionary variation of dorsal pigmentation in Eurasian vipersFernando Martínez-Freiría0Ken S. Toyama1Inês Freitas2Antigoni Kaliontzopoulou3CIBIO/InBIO, Research Center in Biodiversity and Genetic Resources of the University of PortoDepartment of Ecology and Evolutionary Biology, University of TorontoCIBIO/InBIO, Research Center in Biodiversity and Genetic Resources of the University of PortoCIBIO/InBIO, Research Center in Biodiversity and Genetic Resources of the University of PortoAbstract Colouration may endorse thermoregulatory and antipredatory functions in snakes. The thermal melanism hypothesis predicts that dark-coloured individuals are ecologically favoured in cool climates. However, the loss of aposematic and cryptic colourations may imply high predation for melanistic snakes. Here, we used the monophyletic group of Eurasian vipers (subfamily Viperinae) to test whether an increase in the extent of dark area inside the characteristic zigzag dorsal pattern is associated to colder environments. We measured two colouration traits in zigzag-patterned individuals (number of dorsal marks and weighted pigmentation index) and used a phylogenetic comparative approach to explore macroevolutionary patterns of dorsal pigmentation and test whether its extent is associated to ecogeographic characteristics of lineages’ ranges. Phylogenetically-naïve and phylogenetically-informed analyses yielded a significant association between the degree of pigmentation of the zigzag pattern and environmental variables such as solar radiation, elevation and latitude. The degree of pigmentation of the zigzag pattern is highlighted as an adaptive trait that matches range attributes mirroring cold environments irrespective of the phylogeny. These results constitute the first large-scale evidence supporting the thermal melanism hypothesis in snakes, opening new avenues of inquiry for the mechanisms that shape the evolution of colour phenotypes.https://doi.org/10.1038/s41598-020-72871-1 |
| spellingShingle | Fernando Martínez-Freiría Ken S. Toyama Inês Freitas Antigoni Kaliontzopoulou Thermal melanism explains macroevolutionary variation of dorsal pigmentation in Eurasian vipers Scientific Reports |
| title | Thermal melanism explains macroevolutionary variation of dorsal pigmentation in Eurasian vipers |
| title_full | Thermal melanism explains macroevolutionary variation of dorsal pigmentation in Eurasian vipers |
| title_fullStr | Thermal melanism explains macroevolutionary variation of dorsal pigmentation in Eurasian vipers |
| title_full_unstemmed | Thermal melanism explains macroevolutionary variation of dorsal pigmentation in Eurasian vipers |
| title_short | Thermal melanism explains macroevolutionary variation of dorsal pigmentation in Eurasian vipers |
| title_sort | thermal melanism explains macroevolutionary variation of dorsal pigmentation in eurasian vipers |
| url | https://doi.org/10.1038/s41598-020-72871-1 |
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