 The tortoises then spread north to each newly created volcano, resulting in the populations living on Volcan Alcedo and then Volcan Darwin.Recent genetic evidence shows that these two populations are genetically distinct from each other and from the population living on Sierra Negra ("C. guentheri") and therefore form the species "C. vandenburghi" (Alcedo) and "C. microphyes" (Darwin).The fifth population living on the southernmost volcano ("C. vicina") is thought to have split off from the Sierra Negra population more recently and is therefore not as genetically different as the other two.