Over geological time, the earth’s surface and climate have changed, rearranging continental plates and oscillating between a hothouse and snowglobe. These changes have left lasting impressions on the diversity, richness, and distribution of earth’s inhabitants. Identifying evolutionary commonalities as a result of these events is one of the main aims of the field of macroevolution. It is also the main theme which unites my thesis: investigating the influence of changes to the Australian climate and landscape on the organisms which call Australia home. In this seminar, I’ll present a series of projects that discuss evolutionary trends of some of Australia’s most iconic fauna including geckos, macropod marsupials, honeyeater birds, and monitor lizards. These radiations are great for comparative studies because they provide replicated groups which have diversified under similar environmental influences. Importantly though, they differ in absolute diversity, ecology, and behavior. I’ll focus on how changes due to the isolation of the Australian plate, continental aridification, and grassland expansion have impacted the Australian fauna. Hopefully, the patterns I identify and inferences we can draw are intuitive, and help to explain why I find macroevolution and comparative studies so exciting.