Macroevolutionary variation and environmental correlates of scalation traits in Eurasian vipers (Serpentes: Viperinae)

Abstract

Understanding how phenotypic variation across species is shaped by the combination of shared evolutionary history and environmental factors is key to elucidating the processes that underlie biodiversity. In reptiles, morphological traits have traditionally been used to delimit species and make systematic inferences. Recent studies highlight the possibility that phenotypic variation, particularly in scalation traits, might instead be driven by environmental factors and therefore not reflect the phylogenetic relationships among species. In this study, we combined morphological and ecological data in a macroevolutionary framework, in order to describe the morphological variation across species of Eurasian vipers (Serpentes: Viperinae), investigate the phylogenetic structure of scalation traits and test the contribution of environmental factors in shaping morphological patterns. We found considerable variation in all examined traits, which, in most cases, agreed with the phylogenetic relationships among species, reinforcing their usefulness for taxonomic inferences. Interestingly, however, the number of ventral scales exhibited lower phylogenetic signal and a tight association with environmental factors of geographical ranges, suggesting potential adaptive or developmental sources of variation in the trait. This is the first comparative study of macroevolutionary variation in scalation traits in Eurasian vipers, validating the use of most of them for systematic inferences, but also indicating possible environmental factors that might shape phenotypic variation across species.

Lack of country-wide systematic herpetology collections in Portugal jeopardizes future research and conservation

“…The absence of new accessioned specimens does not reflect the current landscape of studies regarding Portuguese herpetofauna. In the last fifteen years, several studies addressed the phylogeography and biogeography of Portuguese herpetofauna (Ambu et al 2023, Camacho-Sanchez et al 2020, Faria et al 2021, Machado et al 2021, Marques et al 2022b, Pinho et al 2009, Rato et al 2013, 2016, Sampaio et al 2014, Santos et al 2012a, b, Vences et al 2014, its morphology and physiology (Enriquez-Urzelai et al , Kaliontzopoulou et al 2012, Lucchini et al 2020, Marques et al 2022a, Martínez-Castro et al 2021, Martínez-Gil et al 2022, Massetti et al 2017, Pinho et al 2022, the revision of long-standing taxonomic and nomenclatural problems (Arntzen 2018, Arntzen et al 2021, Ceríaco & Bauer 2018, Caeiro-Dias et al 2018, Dubois & Raffaëlli 2009, Geniez et al 2014, Sequeira et al 2019, the impact of pathogens on natural populations (De Sousa et al 2012, Rosa et al 2022, Stöhr et al 2015, Thumsová et al 2022, and even the description of new species (Dias-Rodríguez et al 2017, Geniez et al 2014, Fitze et al 2012. However, the majority of specimens used in these studies were either not deposited in Portuguese NHCs or voucher specimens were simply not collected at all and instead substituted by non-lethal methods such as a tail and/or toe clipping and photographs.…”

“…This disconnect is observed in almost all of the above cited recent studies, where the authors do not refer to the deposition of specimens in Portuguese NHCs, nor the use of the already available specimens. This is showcased, e.g., in a recent study on the phenotypic variation of Eurasian viper species, where the authors used data from photographs and museum specimens to assess its relation with macroevolutionary patterns and environmental factors (Martínez-Castro et al 2021). Despite the existence of several specimens of two of the 2022) is one of the few exceptions.…”