The Mediterranean Sea forms of the hub of three great continental masses, Africa, Europe, and Asia, and thus figures prominently in discussions of human origins, population expansions, and culture change. The Mediterranean Basin provides a crucial laboratory for this kind of research on account of its unique ecology, with many endemic taxa enriched over time by periodic incursions of species from adjacent Afro-Arabian, Irano-Turanian, and Pontic biogeographic regions. Some of the earliest evidence for resource intensification among humans occurs in the eastern end of the basin during the Late Pleistocene.
Dr. Stiner's NSF-funded research examines variation in human subsistence and animal community structure across the Mediterranean Basin from 400,000+ to 8,000 years ago in four distinct ecogeographic quadrants. The project is principally a zooarchaeological study, but it includes stable carbon, oxygen and nitrogen isotope analyses of key ungulate taxa in order to track gross variation in vegetation structure, humidity, and temperature through space and time. The proposed research raises questions about Paleolithic subsistence and society in the Mediterranean Basin at larger temporal and spatial scales than could be addressed previously. At issue are the geography and chronology of key transitions in human predatory niches across distinct areas of the region, particularly in terms of prey age selection, dietary breadth, and the intensity of carcass processing efforts. If variation in the prey species hunted by hunters cannot be explained by climate-driving changes in animal community structure, it likely indicates changes in human predatory niche. The research undertakes comparisons of prey species abundance and associations in archaeofaunas across Mediterranean regions and through time, using established criteria for categorizing prey. Predator-prey simulation modeling provides specific expectations in the investigation of hunting pressure and sustainability that can be related changes in human population densities. Climate-driven restructuring of animal communities will be evaluated from independent stable isotope data obtained from tooth enamel carbonate and bone collagen, and from age/size distortion in the population structures of slow-growing small animals and ungulates.
Most enlightening with respect to human subsistence evolution are "niche boundary shifts" and how these transitions cluster in time. Prior research has shown, for example, that the development of the large game hunting niche as defined by prime-age-dominant mortality patterns dates to the onset of the Middle Paleolithic period or before. Far more difficult to explain are the downward shifts in trophic level that characterized later humans. The focus on meat exploitation is an obvious necessity for any zooarchaeological project, but there is more reason for it than just this. Meat is one of the very few sources of complete protein in nature, and its rarity sharpens humans' interest in obtaining it in large packages. Large animals are available sporadically, although sharing can help to remedy the unevenness in the supply. The optimal rate of meat consumption is in small but regular doses, however, and small game can represent reliable, continuous sources in some circumstances. Any subsistence behaviors that enhance the predictability of critical nutrients-such as increasing the nutritional yield and/or more efficient harvesting of resilient (very productive) small game-can improve childhood survivorship and thereby swell a population without a change in birthrate. The human "footprint" on Late Pleistocene ecosystems is difficult to deny in many world regions yet it has been equally difficult to separate from independent paleoenvironmental changes. Distinguishing these effects can only be accomplished through careful control of the key variables. Towards this end, geography is held constant in four study areas of the Mediterranean Basin in order to make sense of variation in Paleolithic game use. The project responds to unique opportunities to close significant gaps in each Mediterranean archaeofaunal series and to understand the causes of subsistence change there. The scale at which this research integrates zooarchaeological and stable isotope data has never before been attempted and will provide valuable reference points for scholars of human dietary change in the Paleolithic and for wild species that eventually came under domestication.
The outcomes of the research are relevant to global questions about the relation between human demography, predatory niche, and animal community changes. The new assemblages targeted by this study will also greatly enhance the value of existing large data sets and help clarify the timing and geographic centers of rapid population growth during the later Pleistocene. To date, most information on human population history has been obtained from comparisons of modern human genetic diversity, which on the whole suggest several demographic pulses originating from western Asia and/or Africa. Time is the most difficult variable to control in these studies, because the biological clocks inferred from gene mutation rates are notoriously inaccurate. By contrast, human demographic pulses evidenced by the zooarchaeological record can be dated by radiometric techniques and their geographic positions compared.
The research program fosters international collaboration in four host countries, where Stiner and students will work directly with local archaeologists and other scientists. A significant proportion of this grant will fund cost-effective graduate student research in the context of cross-disciplinary science. The research also addresses a larger need for integrative approaches with an evolutionary time depth for documenting the long-term place of people in ecosystems, a plea underscored recently by the scientists hosted by the NSF-funded Santa Fe Institute conference in May 2003 on "The Robustness of Coupled Natural and Human Systems".
