Hunters or Scavengers: Meat-Obtaining Techniques of Early Hominids

Searching for behavioral and social traits of humanity's ancestors, we attempt to glimpse into what made prehistoric hominids develop into humans as we know them. Contemporary human undertakings supposedly have a millennia-old cause that lies in the way of life of pre-human ancestors and early humans. Despite the fact scientists are supposed to be objective, more often than not they are influenced in their work and their theories by prevailing social views. One reason for this is the readiness with which scientific ideas are accepted if they support the dominant sociopolitical trends of a particular human culture. For example, it was much 'safer' to claim that human intelligence sprung from the hunting experiences of prehistoric men and ignore women's role in species development by anthropologists in the patriarchal societies of Europe and the United States in the middle of the 20th century. With steady rise of feminism and various movements for gender equality, however, the theories that support the development of humankind through gathering and scavenging techniques and increased role of females in the process are beginning to come to the fore of the science of human ancestry. The most notable fact, however, is that both the supporters of hunting and scavenging theories are using the same fossil data to support their claims, only interpreting it differently. This work will examine a gradual change in interpretation of scientific data available to anthropologists to accommodate the changing social and political values of a contemporary culture, namely that of the United States.

Numerous scientific publications claimed that humans owe the development of their intelligence to the evolutional pressure of successful group hunting. In the words of Washburn and Lancaster, "the biology, psychology, and customs that separate us from apes - all these we owe to the hunters of time past" (cited in Slocum, 1975:37). Supporters of the pre-human hunter theory attributed the development of language and better social interaction to the necessity of early hominids for hunting. They pointed at the fossil sites where animal bones carried the marks of stone tools on them as evidence of humans hunting for their meat (cited in Slocum, 1975:39). Scientists also argued the increased period of infant dependency forced females to remain behind and tend for their young while males hunted and brought the kill back to the 'home base' to share. Therefore, the assumption has been created that the monogamous family units, where a male cared for and supplied his mate and offspring, represented the "selective trait that reduced competition for food" (Lovejoy, 1981:343). All these findings were readily accepted since they fitted well into a male-dominated sociopolitical structure with its notion of 'man-the-breadwinner' and that of a nuclear family being the accepted norm.

Those in support of the man-the-hunter theory cited the shift in early humans' diet from mostly vegetarian to a more significant meat intake as the basis for their conclusions. According to some researchers, the increasingly dry climate forced hominids to more actively pursue prey as a possible food source. They argued that the increase in body and brain size was not possible without meat, a rich source of nutrition, becoming the main part of hominids' diet (cited in Slocum, 1975:44).

The important part of the argument is the definition of hunting. Pat Shipman classified hunting as "the intentional killing of animals larger than 5 kg by hominids using tools and weapons" (1986:28). Since other researchers presented no other clear definition, this paper will accept Shipman's definition as universal.

Because there is a considerable difference between the more modern hominids, such as Homo erectus, and species farther removed from modern humans, such as Australopithecus, both in physical characteristics and in brain size, there is a need to establish which of the human ancestors will come under discussion in this work. According to fossil finds, Homo erectus were the first species of hominids known to science that implemented considerable amount of meat in their diet (Campbell and Loy, 1996:361). It is sensible then to use Homo erectus as the subject for comparison of hunting and scavenging theories. The choice is further justified by the fact that more accurate fossil data of Homo erectus is available than that of Australopithecus.

The Olorgesailie site in northern Kenya was cited as one of the 'proofs' that early humans actively hunted for the meat part of their diet. In this location, scientists uncovered remains of at least 90 representatives of an extinct species of gelada baboon, Theropithecus oswaldi, mixed with over 4,700 stone tools presumably used by early humans (Campbell and Loy, 1996:349). Many anthropologists interpreted this unusual concentration as a site where early humans hunted, probably by way of drive and ambush, and killed and butchered a large band of primates. The enormous number of slaughtered animals 'apparently' pointed only at one possible scenario: A large band, or perhaps even a number of bands of hominids having a successful communal hunt.

What the proponents of the man-the-hunter theory fail to see, or simply choose to ignore, is the fact that the fossil evidence they use to support their findings is inconclusive. In the case of Olorgesailie site, there are several inconsistencies between the actual fossil remains and conclusions that have been drawn from them to support evolution via hunting. First, as was pointed out by Glynn Isaac, the Olorgesailie was most likely a secondary archaeological site, meaning that the bones and the stone tools present there were moved by natural forces, namely a river. According to Isaac, there is a possibility the early humans systematically butchered, and even occasionally hunted, these monkeys, but not by was of organized hunting on a scale the size of the site suggested. Afterwards, the river washed the remains of the prey, as well as tools used to dismember it, downstream where they were redeposited in one spot, creating an unusual concentration (1978:101).

Scientists who proposed the theory of early hominids scavenging for their meat were ignored at the time, especially considering the fact that the evidence they presented was frequently based on the same fossils that the proponents of the hunting theory used. But as time progressed, and the tension created by the Cold War declined, the aggressive tendencies of early humans were finally opened for reevaluation. The rise of feminism, in turn, challenged the notion of women being inferior to men, as well as the presumed infallibility of the nuclear family model. These changes in human social and political views allowed 'man-the-scavenger' theory to be examined in a more favorable light.

The proponents of the new theory took to examining the available sites with more scrutiny, challenging one aspect of man-the-hunter theory after another. After such examination, it became clear that the tool marks on many animal bones found at Olduvai Gorge, Lake Turkana, and other African sites were mostly superimposed over the teeth marks of large carnivores (Shipman, 1985:33). The discovery served as good evidence that "at least some of the hominids' meat-eating was the result of scavenging in competition with carnivores rather than direct hunting (Shipman, 1985:41). The breakage patterns of the animal bones were also examined. This suggested that Homo erectus did not scavenge the carcasses exclusively for meat. Many bones were smashed apart, presumably in attempt to obtain highly nutritious bone marrow. Other bones show the cut marks from stone tools in areas where no significant amount of meat could be obtained, such as lower leg bones (Binford, 1981:294). Robert Leakey suggested that hominids used to forage carcasses for limb tendons, possibly in order to construct slings or carrying bags to assist them in the process of food gathering (cited in Binford, 1985:297).

The next point that was challenged by supporters of the scavenging theory was the tools the early hominids used in order to dismember animal carcasses. Stone and bone artifacts present at the sites appeared to be insufficiently developed to support a vigorous collective hunting of large prey. According to Erik Trinkaus, "archaeological records support the view of archaic humans as gatherers and scavengers - tools are mostly scrapers, bone tools are barely modified from natural form, effective projectiles have not been identified" (1987:125). Owen Lovejoy, whose theory of early development of monogamous family units and labor segregation by gender among early humans actually supports the conservative views of human development, stated that hunting tools could not have preceded processing tools. According to Lovejoy, "progressive development of advanced stone tools from rudimentary weapons is unlikely" (1981:346).

Another important aspect of the hunting theory is the home-base hypothesis, according to which archaic men set up a 'camp' where women, children, and sick awaited the return of the hunters, protected from predators by adult males who were chosen not to participate in the hunt. Sites with heavy concentrations of processed animal bones and stone tools were presented by scientists favoring the hunting theory as proof of actual existence of these bases (Lovejoy, 1981:344).

Scientists supporting the scavenging theory challenged this view by showing the early humans did not possess the traits that the supporters of the hunting hypothesis claimed were necessary for successful hunting, such as language. While Homo erectus were sufficiently developed physically to attempt to hunt down prey, the slow growth of brain in relation to skeleton, as well as the lower jaw and larynx structure that did not allow for the development of cognitive language makes it improbable that these early humans practiced organized hunting of large prey, let alone carried out a complicated task of setting up a home base, which required extensive communication (Trinkaus, 1987:113). Using this evidence, Trinkaus suggested these early representatives of genus Homo "have spent a considerable portion of their activity periods involved in relatively unplanned, opportunistic foraging" (1987:123).

The second point presented by man-the-scavenger theorists provided an alternative interpretation for such fossil sites as Olduvai and Klasies River Mouth. Pat Shipman pointed out that hominids of the period were relatively small - based on fossil remains, average height of Homo erectus was 5.4 feet, with average weight around 128 pounds - and not sufficiently armed to compete with larger predators. Shipman then suggested that the modern fossil sites were actually safe areas for carcass processing, such as trees, for example. Hominids probably brought their butchering tools with them to those sites and frequently left them there after one use and then brought new tools with another carcass. This would explain the heavy concentration of artifacts in one place (Shipman, 1985:37). Another possible explanation could be that the sites were stone caches to which hominids brought the bodies of animals in order to process them (Potts, 1984:341).

In view of these findings, it is fair to speculate that early human ancestors did not obtain most of their meat by hunting. It is possible that, by hunting small game animals, no larger than a squirrel in size, or larger prey that was sick or otherwise disabled, early hominids, with time, acquired enough hunting skills to try their luck with larger animals. Taking the hunting behavior of chimpanzees as an example of cooperation between individuals, scientists can apply it to the behavior of Homo erectus and speculate that the early humans used to ask one another for help in a hunt of larger animals. Cooperating to drive away predators might have also played a role. Otherwise, considering their primitive tools and absence of language as a complex communication device, it is unlikely that hunting was done by early humans on a regular basis and contributed to a major part of their diet. Most likely, hunting was a chancy occurrence, taking place mostly when small or sick animals were found by the hominids on sites of their scavenging expeditions in which they consumed what was left of kills of larger carnivores.

WORK CITED

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