On the state of prey

The question of human origins is a source of endless fascination. When did we evolve? In what parts of the world? And what were the stages and processes by which we changed from ape-like creatures to creatures of our present attainments?

At times one question may take precedence over others, and with the development of new techniques in molecular biology it has been the where and when of human evolution that has assumed transitory significance over the past ten years. Our species, Homo sapiens, is now known to have originated 200,000 to 300,000 years ago somewhere in Africa, it is generally accepted, and many books and papers have been published over the past ten years supporting (sometimes countering) these assertions.

So, we know where and when humans evolved, but there is much more to human evolution than that, such as what did early humans do, how did they do it, even what were they like? It is these questions, and others just as interesting that Mary Stiner approaches in the oddly named Honor Among Thieves.

The subhead, however, is more explicit - A Zooarchaeological Study of Neandertal Ecology - and immediately brings out two important points. First, that this is a book not so much on Neandertals themselves as on the context, the background, in which they lived, and second, that this will be a scientific treatise, not a popular account, thus a difficult read, although rigorously argued, full of information and with many insights into ecological issues affecting human evolution.

Stiner's work is based on her studies of cave fauna associated with Neandertal fossils from Italian caves. Neandertals were prehistoric humans closely related to ourselves, regarded by some as the same species and by others as a separate species. They lived in much of the southern and central parts of Europe from about 350,000 to about 30,000 years ago.

The animal remains in the caves were in some cases brought there by the Neandertals themselves and in others by different carnivorous species, and it is the comparison of Neandertal predation as a means of food procurement with that of other predators that provides the basis of conclusions about what Neandertals did and about their way of life.

Animal exploitation was clearly an important aspect of Neandertal life. Very early in the course of human evolution, between four and two million years ago, human ancestors probably were mainly vegetarian, and when found in caves they arrived there as prey rather than as predator; but with the emergence of the genus Homo, the eating of meat came to assume an ever increasing significance. Prehistoric humans, however, lacked the sophisticated killing power we possess today, and their means of catching and processing animal products were little different from those of contemporaneous non-human carnivores. On this basis, Stiner is able to treat Neandertals as just another species of carnivore, and in making comparisons between human and non-human predatory techniques she has been able to reconstruct many facets of Neandertal behavioural ecology.

Extremely varied methods of analysis have been used. First, animal assemblages brought to caves by humans are distinguished from those resulting from non-human activity. This is done by examining patterns of bone damage: for example, chewing marks indicate carnivore action whereas butchery marks made by stone tools point to human action. Comparisons are made with carnivores such as hyaenas and wolves based on ecological niche theory (to which there is a brief but very sound introduction). Like these carnivores, Neandertals were competent hunters of large and small animals, including marine shellfish on occasion, and the range of species eaten by Neandertals was similar to those eaten by similar-sized carnivores.

Once it is possible to identify certain animal assemblages as having been brought to the cave by humans, the attempt can be made to identify food procurement strategies. By examining the parts of the body of their prey brought to caves by Neandertals, differences in consumption strategies are shown both from other predators and from later Upper Palaeolithic human populations.

The selection of prey is further refined by examining the population structure of the prey remains, for example whether young or old, male or female. Prey selection in these terms sets the limits on the foraging strategies of the Neandertals, and this is fundamental to determining the niche space occupied by them, that is what they did and how they did it in the Mediterranean environments in which they lived during the Upper Pleistocene. Some groups of Neandertals practiced scavenging more than hunting, and, at least initially, hunting was directed more towards small or immature prey. However, a trend towards hunting of adult animals becomes apparent in later Neandertals, with probably greater emphasis on hunting by ambush, and this trend may have continued with the appearance of modern humans.

At this stage of the book, much has been achieved in terms of reconstructing a Neandertal way of life, and many people would have left it at that. Stiner recognises, however, that there is more to it than simply identifying feeding strategies, and she considers the next logical step: the investigation of the population structure of the Neandertals themselves. Unfortunately, sample sizes are simply too small to do this directly and instead Stiner makes a valiant attempt to approach this issue by considering the denning (space occupying) behaviour of carnivores generally. Neandertals appear to have occupied some of the caves on a seasonal basis, and this may be related to differences in hunting and scavenging strategies between Neandertal populations occupying different caves.

For almost the entire book, Neandertals are considered on a par with other predators. This is a refreshing way of looking at things, and much of the success of the results depends on this approach. In the penultimate chapter, however, account is taken of the significant human attributes of tool use and culture. It is found that changes in aspects of tool technology varied with changes in prey patterns, and thus they document an apparently direct response of the Neandertals to the world around them. It is perhaps the most exciting conclusion of this book, for although we know that today humans can respond technologically and culturally to changing pressures, whether imposed from without (by, for example, climatic change) or from within as a result of population growth, the ability of pre-human populations to respond similarly has never before been demonstrated.

Peter Andrews is head of the Human Origins Research Programme, Natural History Museum, London.