Stiner, M. 2002. Carnivory, coevolution, and the geographic spread of the genus Homo
Journal of Archaeological Research 10(1): 1-63
By taking a different approach to hominin interactions with their environment by focusing on changes evident through zooarchaeological analyses in predation niches, Stiner focuses on three niche boundary shifts in Eurasia:
(1) Generalised, indiscriminatory scavenging to increasingly targeting ungulates, ultimately resulting in a new carnivore predation pattern: that of targeting prime adults,
(2) Increased population densities, with targeting of small game animals, and
(3) Increasingly sophisticated technology enabling more organisms to be exploited for consumption and processing.
Stiner wisely avoids the temptation to link her subject matter with a discussion over hominin taxonomy, preferring instead to write: "Hominid taxonomic terms are avoided as much as possible, since most of the evidence for carnivory does not occur in the same sedimentary contexts as classifiable hominid skeletal remains. Suffice it to say, Middle Pleistocene and later hominid populations should have had high dispersal capabilities just to keep themselves in food and thus considerable opportunity to exchange genes."
Stiner's first step was to examine the uniqueness of hominin predation through an overview of nonhuman primates and other carnivores. Baboons and chimpanzees rarely take prey larger than their own body size and are less well equipped to process the carcass as efficiency as wolves or hyenas. Hominins transported their food from the kill site to areas they could more easily defend and process the carcass.
Although the evidence for occupation of Eurasia prior to 500 kya is scarce by comparison with later periods, movement into those areas from Africa would have been facilitated by the hominins' ability to obtain meat as access to plant foods would have been seasonal. Stiner subsequently provides an overview of these early settlements whilst introducing the element of fire, the importance of which she expands upon later: "Fire was almost certainly a part of late Lower Paleolithic technology and may have enhanced hominids' ability to survive Eurasian winters. Oddly, solid cases for controlled use of fire before 25 kya in Eurasia are very few, although fire features as old as 350 kya may exist at Vertesszollos...It is strange that traces of fire are common in archaeological records only by the Middle Paleolithic, becoming a regular part of Middle and Upper Paleolithic peoples' lives thereafter."
After reviewing the evidence concerning the earliest occupations of Eurasia, Stiner begins to focus more tightly on the subject matter of her paper: examining first the relationship between artifacts and faunal remains at various sites. The Lower Palaeolithic and early Middle Palaeolithic sites in Italy, Israel and Turkey are notable for the lack of direct evidence of association between bone accumulations and hominin agencies responsible. Also, the body size of the megafauna found at the majority of these sites are outside the limits seen to be most exploited by modern hunter-gatherers.
This scenario changes after 250 kya in the late Middle Palaeolithic, and Stiner draws attention to increased encephalization around the same time. Cave sites are in prominence, by contrast with "earlier sites...most of which occur in open fluvial, lacustrine, or marsh deposits", with occupational debris from both hominins and carnivores. It is also around this timeframe that emphasis on megafaunal remains decreases and ungulate remains become more prominent. Hayonim Cave, Israel, is dated to c. 170kya and has remains of hunted mountain gazelle, Bos primigenius and fallow deer. Apart from the greater emphasis on hunting prime adult adults, there are other factors which demonstrate the hominins had solid access to large game: comparatively complete body part representation, and percussion fractures and cut marks visible on the faunal bones.
Whilst the age range of animals hunted became more reflective of animals taken by modern hunter-gatherers, this must not be extrapolated to infer that these Middle Palaeolithic hominins followed a modern hunting pattern, as small prey captured "was largely confined to "gatherable marine mollusks, tortoises, legless lizards, and ostrich eggs".
The faunal exploitation is divided into three trends: (1) niche diversification among ungulate predators, (2) small-game use and paleodemography, and (3) Palaeolithic technology and the mother of invention.
Chimpanzees regularly crack nuts using stones and it has been hypothesised that early hominin use of stone as hammers to obtain bone marrow through breaking open the medullary cavities is an extension of similar early usage. At first this would have been part and parcel of scavenging faunal remains, with transport of carcass parts evidence in the faunal record as long ago as 2.5 mya. Thus, combined with later differential preference from prime-age adults, hominin predatory activities differed to a great extent from other carnivore predation patterns and was ecologically without precedent in a strategy which may have resulted in net gains of available game fat for consumption.
Stiner makes a valuable insight when she states: "Selective hunting of prime adult ungulate prey by early humans may inadvertently have set the stage for the coevolutionary relationship we call domestication (the third relationship), although it is not an automatic outcome of human hunting behaviour."
The value of examining the hunting and gathering of small game is that it draws attention to the affects of population densities upon the local ecological systems, and it is here that dramatic changes can be observed in the composition of categories from the Middle Palaeolithic to Epipalaeolithic periods. The average size of tortoises and mollusks taken during the Middle Palaeolithic was large, and whilst these animals remain relatively unexploited their populations continue to exist at high densities due to their slow rate of maturation. High rates of exploitation, by contrast, disrupt their maturation cycle which can be seen in the faunal record through decreases in body size in the hominin occupational sites. Dates for increased harvesting range from 44 kya in Israel to 23 kya at the Italian site of Riparo Mochi. Additional evidence that this trend is due to hominin activities is the lack of correlation with global climatic shifts and the increased importance in diets of faster maturing animals such as hares, rabbits and partridges. These latter, fast moving animals would have required the use of more sophisticated equipment such as snares and traps in order to be captured. These findings lend support to Kent Flannery's hypothesis of a "Broad Spectrum Revolution" with increasing population densities and heightened faunal exploitations. These economic factors in turn would have impacted upon the hominins' social adaptations.
Aside from the odd example of wooden spears from the Middle Palaeolithic, stone-tipped weapons are rare with bone working and bone-tipped weapons appearing in later archaeological records. When considering that the focus on prime-age hunting essentially predates these technological changes, it is evident that technological change cannot in itself be conclusively linked to changes in predation patterns and social co-operation on hunts was essential. These technological improvements would have reduced the amount of time required by hominins in obtaining their prey, which in turn may have lead to increased resource pooling, specialisation tasks and wider social networks of interaction. During the Upper Palaeolithic, population densities and social complexity rose appreciably. Two manifestations of this can be seen in the increased variability of stone tool assemblages as visual marking displays, and in large amounts of personal ornaments. The effect of this pooling would have been to disperse risks in time of ecological crises over wider areas and thereby ensure greater co-operation between neighbouring and distant groups and survival rates.
Magdalenian Epipalaeolithic sites display evidence of further increased sophistication in exploiting carcasses by means of heat-in-liquid techniques for greater extraction of protein and fat via lined pits. Quoting again from Stiner, as the phrasing used cannot be improved upon nor can the essence be captured any other way as eloquently, "still other late specializations in large-game used fostered the productivity of preferred food species and, simultaneously, depressed the productivity of competitors (also true for certain plants). These behaviours include the deliberate torching of range lands to alter vegetal structure and optimize green growth for large herbivores an, more recently, animal domestication. The latter is first indicated by anomalous geographic distributions and radical restructuring of ungulate species profiles in the early Neolithic of western Asia after 10 kya."
The above can best be summarised as comprising eight niche dimensions:
1. Trophic level
2. Consumption efficiency
3. Energy retention efficiency
4. Prey capture efficiency
5. Ungulate age/sex selectivity
6. number foraged substrates
7. Prey type evenness
8. Type of competition
Over time, qualitative changes occurred within these niches by hominins, indicating greater dimensionality and ultimately leading to the Neolithic in Eurasia.