Andites moved to islands of.  Area of highly blended races.  Civilization disrupted by flood in 15,000 B.C.  Geology.  Land trade nearly suspended during nomadic invasions ca. 2500 B.C.; sea commerce in full swing.  Onagar’s headquarters.  Protected by Gibraltar isthmus and Sicilian land bridge in early days of violet race; floods upon their collapse.  Race of.