George Johnson in The New York Times today takes a look at the ongoing scientific debate surrounding the mysterious 13th-century disappearance of the Anasazi culture around the Four Corners. The consensus has long been that the Anasazi were done in primarily by the severe drought that gripped the Southwest in the late 1200s. Johnson notes, though, that the environmental-determinism argument has come under increasing fire and that lately archaeologists are sounding more like Mark Steyn than Jared Diamond. They emphasize that Anasazi settlements may have come under stress as a result of immigration (why didn't they just build a fence?), and subsequently lost confidence in their long-established ideological culture:
By studying changes in ceremonial architecture and pottery styles, Donna Glowacki, an archaeologist at the University of Notre Dame, is charting the rise of what may have been a new puebloan religion. ...
Though the dogma may be irrecoverable, Dr. Glowacki argues that it rapidly attracted adherents. ... Excavations indicate that the population burgeoned along with the new architecture. An influx of different pottery designs suggests immigrants from the west were moving in. Then around 1260, long before the drought, the residents began leaving the pueblo, perhaps spreading the new ideology.
Other archaeologists see evidence of an evangelical-like religion--the forerunner, perhaps, of the masked Kachina rituals, which still survive on the Hopi and Zuni reservations--appearing in the south and attracting the rebellious northerners.
The drought likely ended any hope the Anasazi had of a revival, though. Perhaps the lesson is that environmentalists and civilizational declinists should join forces to make sure we don't suffer the same fate.