Origin, extinction and ancient DNA of a new fossil insular viper: molecular clues of overseas immigration

• Published in: Zoological journal of the Linnean Society 2020, Vol.192 (1)
• Main Authors: Torres-Roig, Enric, Mitchell, Kieren J, Alcover, Josep Antoni, Martínez-Freiría, Fernando, Bailon, Salvador, Heiniger, Holly, Williams, Matthew, Cooper, Alan, Pons, Joan, Bover, Pere
• Format: Article
• Language: English
• Subjects: Animal biology; Archaeology and Prehistory; Biodiversity; Climatology; Earth Sciences; Environmental Sciences; Humanities and Social Sciences; Life Sciences; Paleontology; Populations and Evolution; Sciences of the Universe; Systematics, Phylogenetics and taxonomy; Vertebrate Zoology
• ISSN: 0024-4082; 1096-3642
• DOI: 10.1093/zoolinnean/zlaa094

Viperinae is a subfamily of viperid snakes whose fossil record in the Mediterranean islands is, until now, restricted to 12 palaeontological deposits on seven islands. Revision of the material excavated 30 years ago from the Middle/ Late Pleistocene-Holocene deposit of Es Pouàs [Eivissa (= Ibiza), Balearic Islands, western Mediterranean] revealed about 6000 bones of a small-sized viper across different stratigraphic levels. Its morphological characteristics are different enough to known species of Vipera to warrant the description of a new species, but the nearly complete mitochondrial genome obtained from this snake based on a sample dated to 16 130 ± 45 bp, suggested it belonged to a new insular population of Lataste's viper (Vipera latastei), Vipera latastei ebusitana subsp. nov. Phylogenetic analysis indicates that the dispersal of the ancestors of V. l. ebusitana to Eivissa, most probably from a northeast Iberian population, occurred via overwater colonization < 1.5 Mya, well after the Messinian Salinity Crisis (5.97-5.32 Mya) when land bridges allowed terrestrial colonization of the Balearic Islands by mainland faunas. The morphological differences between V. l. ebusitana and the Iberian populations suggest that it is a new dwarf taxon resulting from insular evolutionary processes, becoming extinct shortly after the first human arrival to this island about 4000 years ago. ADDITIONAL KEYWORDS: ancient DNA-extinction-invasive species-island fauna-Mediterraneanmitochondrial DNA-molecular clocks-new taxa-Quaternary-Serpentes.