- Settlement systems in the Negev, Israel's southern desert, over the past 15,000 years show cycles of demographic rise and decline. Examining site frequency graphs based on systematic survey of 100 km2 grids in different areas and at different geographic scales, these demographic cycles should be tied to patterns of geographic expansions and contractions deriving from different culture-geographic sources. Together this variability suggests instabilities in basic social geographic structures, undoubtedly to be tied at some fundamental level to the difficulties of subsistence in the environmentally harsh desert. On the other hand, if the general pattern of cycles or fluctuations should be tied to some essential property of desert adaptation, the specific incidents of expansion and florescence followed by contraction and decline should be tied to historically particularistic episodes of climatic fluctuation, cumulative technological change, internal social and demographic trends, and inputs from societies on the desert periphery, ostensibly the sedentary core zones. Finally, if these patterns are examined at larger chronological and geographical scales, clear patterns of long-term continuity emerge, belying the idea of essential cultural instability.