Interplay between genetics, ecology and symbionts in two adaptive radiations of New Guinean rodents

Evolutionary radiations after colonization of new areas with free ecological niches are thought to be adaptive, i.e., to arise through ecological speciation. However, allopatric mechanisms may also play a role, especially in topographically diverse environments. We will study a unique system of rodents on the island of New Guinea (NG), where two time-separated radiations happened after over-sea colonizations of the island by the ancestors of NG Hydromyini (7 mya) and Rattini (1mya). Applying a multidisciplinary approach integrating genomics, ecology, parasitology and microbiology, we will characterize and compare the two NG rodent radiations. Using genome-wide sequence data, we will describe genetic patterns within and between rodent species. We will trace the co-evolutionary history of rodent symbionts (gut bacteriome, helminths) and their rodent hosts. These data, along with data on rodent ecology and geography will allow us to examine the mechanisms driving the diversification of NG rodents and compare their relative impacts on the two radiations under study.