Comparative phylogeography of two widespread geckos from the typically narrow-ranging Pachydactylus group in Southern Africa

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Description: Unlike other members of their speciose radiation, Chondrodactylus turneri , a large-bodied, rupicolous climbing gecko, and Pachydactylus punctatus , a typically small-bodied, terrestrial gecko, are broadly distributed, with ranges spanning nearly the width of the Southern African subcontinent and including a variety of ecological and topographical regions. Additionally, both species present complex taxonomic histories with numerous subspecies designations, suggesting possible cryptic speciation across their broad ranges. To evaluate whether C. turneri and P. punctatus are truly widespread, single species or if their anomalous distributions are artifacts of current taxonomy, this study used mitochondrial (ND2) and nuclear (RAG1) sequence data from individuals throughout the ranges of these two focal species and their closest relatives. Reconstructed phylogenetic trees revealed clear and often congruent substructure, including diverse North to South structuring in Namibia and strong East to West structuring across the Southern African subcontinent (albeit with a sampling gap in the Kalahari). Deep divergences between putative conspecifics are as great as those between some recognized sister species pairs in Pachydactylus , reflecting insufficient taxonomic subdivision in C. turneri and P. punctatus as presently construed. Formal revision is anticipated to designate, minimally, one new Chondrodactylus and one new Pachydactylus species in the Kaokoveld region of endemism in southwestern Angola and northwestern Namibia, the likely geographic center from which the broad-ranging groups expanded, and several older names will be resurrected from synonymy.
Language: English
Format: Degree Work