Tight Entrance Cave (TEC) in southwestern Australia provides a Pleistocene sequence documenting the extinction of 14 large mammal species. This record has been interpreted as indicating that extinctions did not occur during or before the penultimate glacial maximum (PGM) and that humans played a primary role in the extinctions. However, it remains possible that the majority of extinct megafauna persisted no later than the PGM. The TEC extinctions correspond with vegetation change, a cooling/drying trend, increased biomass burning, and increasingly unstable small mammal communities. The initiation of these trends predates human arrival on the continent and implies environmentally mediated extinctions.

To promote a dialogue between competing but potentially compatible approaches in American archaeology, Schiffer (1996) examined the relationships between two distinct research programs: "behavioral" archaeology and evolutionary archaeology. An approach grounded in evolutionary ecology was not included in that analysis. In this paper, we reply to Schiffer's call for dialogue by outlining the relationships, as we see them, between evolutionary ecology, selectionist archaeology, and behavioral archaeology. We conclude that evolutionary ecology holds the greatest promise as a scientific approach for the investigation of important problems in human behavioral evolution.

A characteristic feature of human subsistence as the last glaciation ended was the turn towards new food sources, in a ‘broad spectrum’ transformation. Australia took an unusual course, and the trajectory in its arid zone is especially striking. What were the broad spectrum diets in arid Austalia? Why did they arise so late? Did they arise late?

In this concluding discussion the editors explore and summarize issues in the human story of the book's Transitions.

Ethnoarchaeological research has shown that the assumptions formerly guiding the investigation of hunter-gatherer site structure are invalid, at least as general rules. Further research is now required to identify the determinants of site structure and assess their effect. Here I describe those aspects of Alyawara behavior that shape site structure at residential base camps. I then compare certain features of the Alyawara case with those of the !Kung and the Nunamiut. I tentatively infer that most of the variability in site structure in these cases is a function of differences in the degree of reliance on food storage, seasonal variation in weather, household population size, and the length of time activity areas are in use. Predator pressure and the relative importance of interhousehold food sharing may also be involved. The apparent importance of food storage suggests that variation in site structure may parallel Binford's (1980) forager-collector continuum. Further research is required to determine if this is so, and whether other aspects of behavior also affect site structure. These observations have important implications for the conduct of archaeological research, especially for the spatial scales at which analyses of site structure are undertaken, and for the sizes of refuse items considered in such analyses.

In recent years research has been directed to looking for the origins of agriculture and to finding the causes of the transition from hunting and gathering to food production and the domestication of plants and animals. From these studies it has become apparent first, that the transition occurred several times and in several places in prehistory; secondly, that the mechanisms underlying the transition are quite complex; and thirdly that the transition occurred in some regions but not in others, in spite of the prevalence of similar environmental conditions and patterns of exploitation.