Investigation into the Role of Chance and Error in the Diversification of Host Races in Parasitic Cuckoos

Obligate brood parasitism in cuckoos has long been a model for coevolution, resulting in host races defined by egg mimicry. Extensive research has challenged this simple host-parasite narrative, especially how host races are maintained without speciation. Previous empirical research used molecular ecology methods to address to several of these emerging questions, yet results have been mixed and ignored the potential impact of neutral and stochastic processes on population structure and host use. Here, I used simulation to understand how drift and error in host switching shape patterns of genetic differentiation under different selection paradigms. These simulations assumed that both sexes exhibit host preference and contribute to egg mimicry. I provide evidence that drift and discordance in host preference alone can generate patterns of genetic variation observed in the field. While natural selection undoubtedly shaped cuckoo populations, this work highlights how stochastic processes can lead to patterns both similar and dissimilar to those predicted by the host-parasite narrative.Master of Scienc