Thursday, July 22, 2010
Animal Connection: New Hypothesis for Human Evolution and Human Nature
- What Does China Tell Us?
Pat Shipman has a new book in press (see above title) and an academic article coming out in Current Anthropology which elaborates on the role animal species have played in the evolutionary transformation of man-apes into ape-men and eventually fully human beings, replete with the ability to communicate using symbolic representations (aka art). Central to her hypothesis is the idea that the “interdependency of ancestral humans with other animal species -- "the animal connection" -- played a crucial and beneficial role in human evolution over the last 2.6 million years” (see write-up in Science Daily). Basically Shipman argues that as humans assumed the role of a top predator they began to study the behavior of their competitors (and I assume their prey) in order to learn how to hunt. They thus began to identify and empathize with other species. Symbolic representations, domestication and language were the ultimate end results.
Her thesis makes some interesting observations and I’m sure there is an element of truth in it. But is it the whole truth and nothing but the truth? I doubt it. I haven’t yet read the book or article (they’re both in press) so I don’t know how she develops her ideas, but in regards to symbolic representations of animals this occurs at the tail-end of the human Odyssey. It certainly took a long time to materialize. The same for domestication and perhaps language as well. They all seem to be manifestations of modern human behavior that distinguishes us from our archaic forebears. The earliest scratch marks on ochre forming geometric designs date to ~ 70,000 from the Middle Stone Age site of Blombos Cave in South Africa, while animal representations occurred much later in time during the upper Paleolithic in Europe. Domestication occurred primarily during the Neolithic.
Perhaps the earliest intentional marks on a material object however are recorded in China. The abstract of an article published in the Chinese Science Bulletin in 2004 (Gao Xin et al.), regarding excavations at Xinglongdong in the Three Gorges Region of South China, states:
Rich paleoanthropological materials were unearthed in primary context from the Xinglongdong Cave in Fengjie County, Chongqing, South China, including a human tooth, numerous mammalian fossils, some stone artifacts and a Stegodon tusk exhibiting intentional engravings. Based on biostratigraphic data and uranium series dating, the cave was utilized as a human shelter about 120000 to 150000 years ago. It is the first time that an archaic Homo sapiens fossil has been unearthed from the Three Gorges Region. Engravings on the Stegodon tusk appear in groups, making up simple and abstract images. It is the earliest known engravings created by human beings; it exhibits great potential for the study of the origin of art and the development of ancient cultures in south China and bears important implications for the origin of modern humans in East Asia.The relevant section of the article reads as follows:
Two elephant (Stegodon orientalis) tusks, belonging to 2 individuals, were unearthed from the bottom of the second layer inside the cave. These two tusks were apparently intentionally placed parallel to one another (Fig. 5), which initially drew the attention of the second author. After cleaning, engraved lines became apparent on the surface of one tusk. The tusk is measured 184 cm long with the tip partially broken. Engravings appear on the tip of the tusk, concentrated in an area of 50 cm². These engravings in clude straight (vertical and oblique) and curved lines, and are simple but deep and bold, appearing in groups. Here we describe two such groups of incisions: Group 1 consists of six engraved lines and can be further divided into three parts, arranged vertically. The distal sector includes three fine, short, oblique lines (12 mm, 26 mm, and 16 mm long, respectively). These lines stretch toward the tip of the tusk, with two engravings initiating from the groove of the third. The middle part consists of a short, shallow, horizontal line (7 mm long and 1.4 mm wide) and a long, deep, vertical line (37 mm long and 1.5 mm wide). These two lines intersect forming a roughly cross-shaped figure. The proximal segment includes only one oblique line (41.5 mm in length), starting near the tail of its vertical counterpart. Under a microscope, these engraved lines exhibit “V” shape in cross section. Compositionally, this group somewhat resembles a leafless branch (Fig. 6(a)). Group 2 consists of four lines. The first one is straight and relatively long (110 mm long and 1.21.5 mm wide), running parallel to the long axis of the tusk. The other three lines are curved and relatively short (20 30 mm) and wide, clearly stretching from the mid-section of the first, yielding a crest-shaped composition (Fig. 6(b)). The tasks and engravings have been examined from many aspects, taphonomically, morphologically, mechanically, and artistically. The two tusks of different individuals appear parallel to each other in the deep end of the cave, about 50 m away from the entrance; no remains of other body parts were found in close association with them, which indicate that the tusks were neither the remain of in situ natural death of the elephants nor the result of other elephants’ movement of the dead companion, an elephant behavior that has been observed occasionally. The possibility of other animal drawing these huge and meat-less teeth to the deep side of the cave can also be eliminated. The nature of the deposit indicates that flowing water was not a factor in the formation of the archaeological record. Therefore, it is reasonable to believe that the presence of the tusks was the result of human transportation and arrangement. The lines on the tusk described above are distinct from marks or traces found on animal bones and teeth produced by natural agents such as weathering, root etching, abrasion, trampling, animal gnawing, and scratching[ 7], and they can be easily differentiated from rubbing traces created when the animal was alive, which normally appear in groups of oblique, short, thin, shallow and parallel lines (Fig. 7). The fact that such engravings appear on elephant tusk eliminates the possibility that they are tool marks resulting from butchering or skinning of game. The means by which the lines were created and the way they were composed indicate that they are not the careless or accidental products of human beings either. The above observations and analyses assure us that the lines on the tusk are human intentional creations. They exhibit some unique characters: (1) They are deep and bold and exhibit clear starting points, unlike natural rubbing traces or damage marks; (2) they vary in length, depth, starting points, and stretching directions; (3) they are generally V-shaped in cross-section, typical of sharp stone tool marks, different from animal tooth marks that are normally U-shaped in cross-section; (4) the curvilinear lines with different curvatures cannot be explained by any natural formation; (5) correlations and connections can be found among these lines; and (6) they are arranged in groups and form regular patterns (Fig. 6(c)). Therefore, these images were apparently intentionally engraved to imitate natural phenomena or attempt to express some abstract thought, the significance of which we cannot yet fully comprehend. Questions might arise on the workability of the elephant tusk by ancient hominids using stone tools. Actually Stegodon tusks are not very hard materials. Unlike young Stegodon individuals whose tusks were covered by a thin layer of enamel, adult Stegodon’s tasks remained only dentine, enamel was usually wore off. Simple experimentations were carried out by the team using limestone tools similar to those found in the Xinglongdong cave to engrave on a piece of modern elephant tusk, and similar lines were created. The presence of some flint chunks and debris from the cave can be taken as a clue that more suitable engraving tools might exist at the site.
This Chinese evidence and the engravings in South Africa suggest that the earliest attempts to convey information symbolically did not entail naturalistic representations of animals, but abstract representations that are currently hard to interpret.In their discussion of the site the authors state the following:
The elephant tusk with human engravings unearthed from the cave is a significant discovery. A series of analysis conducted on this finding, including the taphonomic context and the appearance, directions, curvatures, morphology and composition of the lines, convincingly points to the fact that these lines on the tusk are distinct from marks or traces found on animal bones and teeth produced by various natural agents; they are the result of human engravings, and they were apparently intentionally engraved to imitate natural phenomena or attempt to express some abstract thought. Therefore, the tusk yields the earliest archaeological evidence that could be related to primeval artistic creativity by human beings ever found so far.Once again we're finding that simple scenarios based on an incomplete and inadequate archeological and fossil record tend to skew our understanding of the human past. This is not to denigrate what others have found and the interpretations that have been previously made. But we should keep an open mind to new evidence and their implications once discoveries in hitherto poorly sampled regions of the world come to light. There is only one human story to be told but we as yet can barely see its outline nonetheless its details.
Human artistic expression is undoubtedly rooted in the Paleolithic. The fragmentary data collected so far prevent us from reconstructing a precise history of its development in that remote period. However, newly unveiled archaeological evidence enables us to make a rough sketch of how such a process might have played out. Human and other animal figures and cave paintings discovered in Africa and Europe, some of which can be dated to 30-40 ka, have been generally accepted as unquestionable early human art works. The discovery of red ochre pieces with geometric engravings from the Blombos Cave in South Africa might have traced the history of human artistic activity back to 77 ka. Ivory engravings of 120,000 - 150,000 years old reported in this paper provide new clues on the origin of human artistic creations. Based on archaeological evidences, we believe that even though the general tendency of pictorial art during the past 30,000 years is from realism to abstract, it might have experienced an opposite developmental trend in the embryonic stage: the earliest work might have initiated from single, simple and rough engraved lines, poorly controlled, highly abstract in character and difficult for us to interpret. Ivory engravings reported in this article are such examples. A further advance may have involved multiple, finer, more complex and better-controlled lines, possibly yielding geometric or other recognizable compositions, which are still subject to varying interpretations. Ochre engravings from the Blombos cave may be taken as a representative of this stage. As artistic expression matured carved, sculpted, or painted figures or representations of anthropomorphic, zoomorphic or other subjects, with early interpretable morphologies and sometimes meanings, were developed. Engraved animal figures and female anthropomorphs discovered at Mal’ta and other Upper Paleolithic sites in south-central Siberia and the parietal art associated with Magdalenian horizons from Spain and southern France  are prime examples of this stage.
Artistic creativity is one of the unique attributes of modern human cognition and behavior. Therefore, one research topic closely related to the origin of art is the origin of modern humans. For years, two hypotheses in this regard, namely “Out of Africa” vs. Multi-regional continuity”, stand in sharp opposition to each other; both are seeking archaeological backing. Ochre engravings from the Blombos cave were quickly assigned as the supporting evidence for the former theory upon their discovery. Are the materials described in this paper supportive of the latter? We can at least conclude that the human ancestors who occupied Xinglongdong Cave on the eastern periphery of the Qinghai-Tibet Plateau some 120-150 ka already possessed consciousness and behavior patterns that might be described as “modern”. They not only made and used stone tools, but also attempted to use engravings and possibly other means to express complex ideas that are as yet incomprehensible to modern-day humans. Therefore, this discovery not only provides invaluable information for the study of the origin of art and the development of ancient cultures in the Three Gorges Region of south China, but also bears important implications for the origin of modern humans in East Asia.