Across the Gobi Desert: impact of landscape features on the phylogeography and release calls of the Mongolian Toad Strauchbufo raddei in East Asia
Landscape structures drive biogeographic patterns and population connectivity of animals distributed across diverse biotopes. Here, we provide new fresh insights on the genetic structurephylogeography of the widespread Mongolian Toad, Strauchbufo raddei on diverse landscapes of East Asia. We then refine its phylogeographyreconstructed the biogeography of S. raddei throughout Eastnortheast Asia (n N = 299; assembled up to 2,613 bp of concatenated CR-COI-16S-12S fragments) using fossil-based molecular dating and genetic connectivity assessments. In addition, we refined our analyses and address phylogenetic andpast population dynamics and geographic variations in release calls for the clades occurring in the steppes of northern Mongolia and the Amur River basin (n N = 147). Our results support recovereda dual origintwo separate ancestors of S. raddei across East Asia, and estimated asupported a basal split Mid-Miocene split between the northeastern and southern cladeslineages in Middle Miocene (c. 9.48 – 13.77 Mya). Ancestral range estimates suggest a the earliest radiation of thewithin northeastern lineage, likely followed by dispersal andattributes to the aridity-induced vicariance and dispersal from the central Asian steppes (Late Miocene; c. 7.89 [5.25-11.50] Mya). The southern lineage emerged subsequently from glacial refugium, c. 6.84 [3.48-2.63] Mya, expanding northward from the to thewestern margin of the Hentiyn Mountains, crossing of, and most likely across the Gobi Desert and Mongolia, c. 2.60 (1.15-3.72) Mya. Despite effective genetic barrier found in pre-Tibetan Plateau clade, The the trajectory of migrationhaplotype network however highlighted the presence of effective gene flow cross-landscapes, notably among central and northeastern Chinese clades occupied the habitats defined as steppe, river basin and canyon. Significant variation in release calls between the two mainnorthern Mongolia and Amur River Basin lineages clades reflected the a geographic isolation, and the supporting the northern refugia and post-glacial expansion of southern lineage into northwestern Mongolia, . likely linking the variations in release with the evolutionaryInterestingly, our finding indicates release calls can reflect to historical factor linked to phylogeography history of the clade.