Frank E. Zachos studied biology, history of science and philosophy and is presently Head of the Mammal Collection at the Natural History Museum Vienna and affiliated professor at the Department of Genetics at the University of the Free State in Bloemfontein, South Africa. His biological research focuses on the intraspecific biodiversity, population genetics, biogeography and conservation of mammals and birds. His main theoretical interests comprise species concepts and the species problem, the foundations of taxonomy and systematics and the history and philosophy of evolutionary biology.