Using Nuclear Introns to Infer the Evolutionary History of the Understudied Australian Red Robins

Abstract

The Australasian red robins (genus Petroica) are commonly used as a textbook example of island speciation due to the radiation of the species outward from the Australian mainland (Mayr, Animal Species and Evolution, 1950). Although their common name sounds familiar, the Australian Robins are a distinct group not at all closely related to our American Robin. Traditionally, the evolutionary relationships within the genus have grouped the mainland Scarlet Robin (Petroica boodang) with the Pacific Robin (Petroica multicolor) which is found on nearby islands, such as Solomons Island, Vanuatu, Fiji, and Norfolk Island. However, recent molecular based phylogenies suggest this traditional view to be flawed. A mitochondrial DNA study by Christidis et al. (2011) puts the Scarlet Robin with the Flame and Pink Robins instead of with the Pacific Robin. In previous studies by the Omland lab, mitochondrial gene trees have been shown to be problematic in inferring species trees (Jacobsen and Omland, 2011). Therefore, here we test the validity of the traditional and mitochondrial phylogenies using nuclear DNA to infer a species tree of the Petroica genus.