KIMBERLY D. KORNBACHER
THE FOUR ‘NATURAL’ HORSEMEN OF THE APOCALYPSE. Cultural development in the Central Andes cannot be interpreted without correlating the cultural record with geological and climatic change. This region is subject to many of the natural catastrophes that assail other areas of the world, but nowhere else do they occur in such profusion. The disasters range from localized avalanches, or huaycos (floods of liquid mud, usually transporting large boulders), to volcanic eruptions, earthquakes, and El Niño rainfall and drought events that bring severe devastation to vast areas of the Central Andes.
Extreme environmental events and processes have not traditionally played a prominent role in our understanding of evolution, and the process itself has generally been considered slow and gradual (Hoffman and Parsons, 1997:16). Recent studies of non-human organisms have shown, however, that catastrophic events and extreme environmental processes may intensify the effects of natural selection and cause rapid evolutionary change (e.g. Grant, 1986; Gibbs and Grant, 1987; Benton and Grant, 1996). As the number of evolutionary biologists documenting and recognising the importance of extreme environmental change in precipitating extensive evolutionary change increases, the traditional ‘slow and steady’ perspective of evolution is shifting (Gould and Eldridge, 1993; Hoffman and Parsons, 1997). Unfortunately, similar gains are lacking in studies of human prehistory. Perhaps due to our unwillingness to examine the ongoing evolution of our own species, or maybe because of the complexities involved in doing so, the findings of evolutionary biology have not been widely applied to studies of ourselves. Yet archaeologists studying cultural change over a long time scale are uniquely situated to research the nature of evolutionary responses to extreme environmental change in humans (Torrence and Grattan, this volume, Chapter