Critical perspectives on historical collapse.

Historical collapse of ancient states or civilizations has raised new awareness about its possible relevance to current issues of sustainability, in the context of global change. This Special Feature examines 12 case studies of societies under stress, of which seven suffered severe transformation. Outcomes were complex and unpredictable.

Collapse, environment, and society.

Historical collapse of ancient states poses intriguing social-ecological questions, as well as potential applications to global change and contemporary strategies for sustainability. Five Old World case studies are developed to identify interactive inputs, triggers, and feedbacks in devolution. Collapse is multicausal and rarely abrupt.

Dating and context of rock engravings in southern Africa.

Rock art is seldom recovered from sealed archeological contexts and is therefore difficult to date or integrate with other artifactual assemblages. South African engravings, found on low rocks at open-air sites, exemplify the problem. Multiscale spatial study of technique, thematic variation, faunal content, geoarcheological paterning, settlement history, and ethno-archeological setting provides coherent information on environment, time, and group identity.