HOSTILE · Ecological genomics of vertebrates across environmentally hostile naturally fragmented paleosurfaces

Long-term population persistence in fragmented landscapes is of interest to evolutionary and conservation biologists. Although the causes of population fragmentation and their effects on genetic structure have been investigated in post-Pleistocene “nutrient-rich” landscapes, pre-Pleistocene nutrient-poor landscapes (paleosurfaces) have seldom been considered by population geneticists. The biotic assemblages of paleosurfaces differ fundamentally in their traits from biotas evolving in post-Pleistocene landscapes. It has been hypothesized that they display more complex population dynamics due to the persistence of old lineages, refugial phenomena, inbreeding, adaptations to resource-limited, highly competitive environments, and high levels of resilience to lower evolutionary potential. In this context, the Pantepui region in the western Guiana Shield is of particular interest as it harbours numerous isolated Precambrian sandstone tabletop mountains (tepuis) reaching up to 3000m and is renowned for its floral and faunal endemism. The “Lost Worlds” of tepui summits face particularly hostile, challenging environmental conditions, and their characteristic vegetation grows on highly acidic, oligotrophic soils. My overarching objective is to determine the extent to which the genetic structure, phenotypic traits, and, ultimately, the evolutionary trajectories of vertebrates are impacted by these environmentally hostile, naturally fragmented, paleosurfaces. I will apply state of the art population genomics and imaging technologies (histology, micro CT scanning) integrated with systems-level ecological data to three tepui summit endemic amphibian and reptile taxa distributed across the summits of four neighbouring isolated tepuis. This will yield new insights into the ecological genomics of this extremely hostile environment, and a basis for addressing fundamental questions by comparing and contrasting with other better known species and their less hostile environments.