Complex sentence: He studied sociology at the University of Havana, under Fernando Ortiz, the pioneer of Cuban anthropology, whose studies of Afro-Cuban cultures influenced many of the themes, both literary and scholarly, of Barnet.
Split into simpler sentences: He studied sociology at the University of Havana, under Fernando Ortiz, the pioneer of Cuban anthropology. Fernando Ortíz's studies of Afro-Cuban cultures influenced many of the themes, both literary and scholarly, of Barnet.