Insights into the evolutionary and demographic history of the extant endemic rodents of the Galápagos Islands

Research reveals that the extant endemic rodents of the Galápagos Islands originated from two distinct colonization events, with the ancestor of Nesoryzomys arriving during the Pliocene and Aegialomys during the middle Pleistocene. Phylogenetic analysis using mitochondrial DNA (mtDNA) D-loop region confirmed monophyly in all four surviving species: Aegialomys galapagoensis, Nesoryzomys narboroughi, N. swarthi, and N. fernandinae. The study also found that populations on each island exhibit high genetic diversity with signs of recent expansion, though conservation status requires further assessment. These findings suggest a complex evolutionary history for Galápagos rodents, emphasizing the need for ongoing monitoring and future research using genome-wide markers to deepen understanding of their origins and relationships.

Castañeda-Rico, S., Johnson, S. A., Clement, S. A., Dowler, R. C., Maldonado, J. E., & Edwards, C. W. (2019). Insights into the evolutionary and demographic history of the extant endemic rodents of the Galápagos Islands. Therya, 10(3), 213–228. https://doi.org/10.12933/therya-19-873