Colour

source: The Guanacaste Journal

Dental modification in Greater Nicoya

By Frederick W. Lange*

My Guanacaste Journal articles often result from particular coincidences in my continually multi-tasking life, and this is another such effort. Some time ago, when I was still at the University of Colorado at Boulder, I had asked a colleague in physical anthropology what the life span of human dentition was, in evolutionary terms. His response was, “About 40 years”; and after that, if not before, “it was all fillings and false choppers.”

Now that I am safely on the other side of 40 years, and having had only moderately good dental habits as a child and adult, I have been spending a considerable amount of time undergoing dental and periodontal treatment. I also had been looking at the image that accompanies this article in the course of a study that required a review of dental modification in both Mesoamerica and South America (I had grown up referring to the filed treatment shown in the illustration as “mutilation,” but since the individual had actually requested the filing to enhance his appearance, “modification” seems to be a better term. This was not torture, but beautification!

In dental school, tomorrow’s dentists learn that the main functions of our teeth are for chewing, facilitating speech, and providing aesthetics. To this has been added the anthropological term “paramasticatory,” which is the alteration to our dentition by the daily use of our teeth as tools, or by intentional alteration. Among the daily use examples that come to mind are:

(1) When I was a kid I had the good fortune to spend a lot of time in Bandelier National Monument in New Mexico. There, the rocks that were utilized to grind the corn (manos and metates) were so soft that it has been calculated that 30 percent of everything they ate that had been ground between two rocks was volcanic sand. From the human skulls I was able to look at in the storage areas of the monument, anyone over the age of 20 was lucky to have two teeth that still met, and those teeth that remained were sanded flat to the exposed tooth pulp by the continual chewing of sandy tortillas.

(2) Some years later as a young professional archaeologist, I had the opportunity to excavate burials in an Afro-American slave cemetery on the island of Barbados. There we could tell which deceased slaves had been pipe-smokers, since gradually a gap is worn between the two teeth where a pipe-smoker grips the mouth piece of the pipe. Interestingly, women as well as men had the tell-tale pipe-smoking gaps in their dentition.

(3) Among the European Neanderthals, whose reputation continues to be refurbished from brutish cavemen to heavy but enlightened ancestors (see, for example, the article in National Geographic magazine from October 2008). Their dentition reveals that they (both men and women) spent considerable time chewing hides to soften them for winter weather clothing.

Refocusing this article on the intentional alteration or modification of teeth allows us to mention that there were three most common means of purposeful modification utilized by Native Americans in Mesoamerica and, to a lesser extent, South America. These are filing, incising, and inlays. Inlays with filing is the technique shown in the Guinea Incised vessel image that accompanies this article. Human skeletal materials with filed teeth have been excavated from the Bay of Culebra and El Moral de San Blas areas of Guanacaste, so there is independent archaeological proof of the dental modification shown so vividly in the image. Many years ago, while living in Costa Rica, I was told of a burial that a pot-hunter had excavated, in which a ceramic vessel portraying filed teeth was found immediately next to a skeleton whose upper and lower jaws had filed teeth that matched the pattern shown on the pot.

Dental modification was widely practiced in prehistoric times and in terms of the example illustrated here we can ask: Was the filing because of familiarity with a Mesoamerican pattern or a South American custom? More research needs to be done, but I suspect the tooth filing in this specific case was a result of Mesoamerican influence somewhere around 1,700 ago.

Extract from National Geographic article:

Last of the Neanderthals

Neanderthal society may have differed in another way crucial to group survival: what archaeologists call cultural buffering. A buffer is something in a group's behavior—a technology, a form of social organization, a cultural tradition—that hedges its bets in the high-stakes game of natural selection. It's like having a small cache of extra chips at your elbow in a poker game, so you don't have to fold your hand quite as soon. For example, Mary Stiner and Steven Kuhn of the University of Arizona argue that early modern humans emerged from Africa with the buffer of an economically efficient approach to hunting and gathering that resulted in a more diverse diet. While men chased after large animals, women and children foraged for small game and plant foods. Stiner and Kuhn maintain that Neanderthals did not enjoy the benefits of such a marked division of labor. From southern Israel to northern Germany, the archaeological record shows that Neanderthals instead relied almost entirely on hunting big and medium-size mammals like horses, deer, bison, and wild cattle. No doubt they were eating some vegetable material and even shellfish near the Mediterranean, but the lack of milling stones or other evidence for processing plant foods suggests to Stiner and Kuhn that to a Neanderthal vegetables were supplementary foods, "more like salads, snacks, and desserts than energy-rich staple foods."

Their bodies' relentless demand for calories, especially in higher latitudes and during colder interludes, probably forced Neanderthal women and children to join in the hunt—a "rough and dangerous business," write Stiner and Kuhn, judging by the many healed fractures evident on Neanderthal upper limbs and skulls. The modern human bands that arrived on the landscape toward the end of the Neanderthals' time had other options.

"By diversifying diet and having personnel who [did different tasks], you have a formula for spreading risk, and that is ultimately good news for pregnant women and for kids," Stiner told me. "So if one thing falls through, there's something else." A Neanderthal woman would have been powerful and resilient. But without such cultural buffering, she and her young would have been at a disadvantage.

Of all possible cultural buffers, perhaps the most important was the cushion of society itself. According to Erik Trinkaus, a Neanderthal social unit would have been about the size of an extended family. But in early modern human sites in Europe, Trinkaus said, "we start getting sites that represent larger populations." Simply living in a larger group has biological as well as social repercussions. Larger groups inevitably demand more social interactions, which goads the brain into greater activity during childhood and adolescence, creates pressure to increase the sophistication of language, and indirectly increases the average life span of group members. Longevity, in turn, increases intergenerational transmission of knowledge and creates what Chris Stringer calls a "culture of innovation"—the passage of practical survival skills and toolmaking technology from one generation to the next, and later between one group and another.

Whatever the suite of cultural buffers, they may well have provided an extra, albeit thin, layer of insulation against the harsh climatic stresses that Stringer argues peaked right around the time the Neanderthals vanished. Ice core data suggest that from about 30,000 years ago until the last glacial maximum about 18,000 years ago, the Earth's climate fluctuated wildly, sometimes within the space of decades. A few more people in the social unit, with a few more skills, might have given modern humans an edge when conditions turned harsh. "Not a vast edge," Stringer said. "Neanderthals were obviously well adapted to a colder climate. But with the superimposition of these extreme changes in climate on the competition with modern humans, I think that made the difference."

Which leaves the final, delicate—and, as Jean-Jacques Hublin likes to say, politically incorrect—question that has bedeviled Neanderthal studies since the Out of Africa theory became generally accepted: Was the replacement by modern humans attenuated and peaceful, the Pleistocene version of kissing cousins, or was it relatively swift and hostile?

"Most Neanderthals and modern humans probably lived most of their lives without seeing each other," he said, carefully choosing his words. "The way I imagine it is that occasionally in these border areas, some of these guys would see each other at a distance…but I think the most likely thing is that they excluded each other from the landscape. Not just avoided, but excluded. We know from recent research on hunter-gatherers that they are much less peaceful than generally believed."

"Sometimes I just turn out the lights in here and think what it must have been like for them."

Evolutionary biologist Clive Finlayson, of the Gibraltar Museum, was standing in the vestibule of Gorham's Cave, a magnificent tabernacle of limestone opening to the sea on the Rock of Gibraltar. Inside, fantastic excretions of flowstone drooled from the ceiling of the massive nave. The stratigraphy in the cave is pocked with evidence of Neanderthal occupation going back 125,000 years, including stone spearpoints and scrapers, charred pine nuts, and the remains of ancient hearths. Two years ago, Finlayson and his colleagues used radiocarbon dating to determine that the embers in some of those fireplaces died out only 28,000 years ago—the last known trace of Neanderthals on Earth. (Other hearths in the cave may be as young as 24,000 years old, but their dating is controversial.)

From pollen and animal remains, Finlayson has reconstructed what the environment was like from 50,000 to 30,000 years ago. Back then, a narrow coastal shelf surrounded Gibraltar, the Mediterranean two or three miles distant. The landscape was scrub savanna scented with rosemary and thyme, its rolling sand dunes interrupted by the occasional cork oak and stone pine, with wild asparagus growing in the coastal flats. Prehistoric vultures, some with nine-foot wingspans, nested high up in the cliff face, scanning the dunes for meals. Finlayson imagines the Neanderthals watching the birds circle and descend, then racing them for food. Their diet was certainly more varied than the typical Neanderthal dependence on terrestrial game. His research team has found rabbit bones, tortoise shells, and mussels in the cave, along with dolphin bones and a seal skeleton with cut marks. "Except for rice, you've almost got a Mousterian paella!" Finlayson joked.

But then things changed. When the coldest fingers of the Ice Age finally reached southern Iberia in a series of abrupt fluctuations between 30,000 and 23,000 years ago, the landscape was transformed into a semiarid steppe. On this more open playing field, perhaps the tall, gracile modern humans moving into the region with projectile spears gained the advantage over the stumpy, muscle-bound Neanderthals. But Finlayson argues that it was not so much the arrival of modern humans as the dramatic shifts in climate that pushed the Iberian Neanderthals to the brink. "A three-year period of intense cold, or a landslide, when you're down to ten people, could be enough," he said. "Once you reach a certain level, you're the living dead."

The larger point may be that the demise of the Neanderthals is not a sprawling yet coherent paleoanthropological novel; rather, it is a collection of related, but unique, short stories of extinction. "Why did the Neanderthals disappear in Mongolia?" Stringer asked. "Why did they disappear in Israel? Why did they disappear in Italy, in Gibraltar, in Britain? Well, the answer could be different in different places, because it probably happened at different times. So we're talking about a large range, and a disappearance and retreat at different times, with pockets of Neanderthals no doubt surviving in different places at different times. Gibraltar is certainly one of their last outposts. It could be the last, but we don't know for sure."

Whatever happened, the denouement of all these stories had a signatory in Gorham's Cave. In a deep recess of the cavern, not far from that last Neanderthal hearth, Finlayson's team recently discovered several red handprints on the wall, a sign that modern humans had arrived in Gibraltar. Preliminary analysis of the pigments dates the handprints between 20,300 and 19,500 years ago. "It's like they were saying, Hey, it's a new world now," said Finlayson.j