 It is thought to be derived from a different colonization event than the others.A colonization from the island of Santiago apparently gave rise to the Volcan Wolf species ("C. becki") while the four southern populations are believed to be descended from a second colonization from the more southerly island of Santa Cruz.Tortoises from Santa Cruz are thought to have first colonized the Sierra Negra volcano, which was the first of the island's volcanoes to form.