Lately, though, the nanoSEM has been enlisted for a different kind of task: determining the authenticity of ancient Mesoamerican artifacts.
In ongoing studies, Rose and his colleague Jane Walsh have now analyzed hundreds of artifacts, including carved stone figurines and masks and ceramic pieces from the ancient Olmec, Maya, Teotihuacan and Mezcala civilizations dating from 1500 B.C. to A.D. 600. “With our modern imaging and analytical tools we can look at objects at very high magnification, which can reveal new details about how, and sometimes when, objects were created,” he said.
Rose will discuss the technology at the AVS 61th International Symposium and Exhibition, to be held Nov. 9-14, at the Baltimore Convention Center in Baltimore, Md.
The nanoSEM used by Rose and his colleagues has the ability to function over a range of pressures. “Being able to work in the low-vacuum mode allows us to put samples into the microscope au naturel without coating them with an electrically conductive material such as carbon, which would be almost impossible to remove from a specimen,” he said.
In one study, Rose and colleagues used the nanoSEM to study stone masks from Teotihuacan, a pre-Columbian site located 30 miles northwest of Mexico City. The masks, about the size of a human face, were too big to be put into the device (and, more importantly, could not be removed from their respective museums or drilled or otherwise altered to obtain samples for analysis). However, silicone molds that were made of the objects to study tool marks with an optical microscope did remove tiny mineral grains from deep within cracks and drill holes. Chemical evaluation of these grains using the nanoSEM’s X-ray spectrographic analysis system showed that some were diatoms—common single-celled algae with cell walls made of silica. Diatomaceous earth is “a very fine powdery siliceous rock comprised entirely of diatoms that would make very nice polish for the stone of these specific masks,” Rose said. “We believe we found abrasive grains and polish that was used in the manufacturing process.”
In a separate study of artifacts confiscated by the federal government, the researchers found some pieces to be partially coated with a layer of what looked to be modern gypsum plaster. In other words, the pieces were fakes. However, Rose noted, a surprisingly small percentage of the objects evaluated to date have shown modern tools marks or other evidence of recent origins. One unique ceramic handled pot analyzed in detail, for example, had five chemically distinct layers that appeared to be original Olmec fresco paint—a level of craftsmanship that, he said, is unlikely to have been the work of modern artisans.
Her findings, based on the comprehensive analysis of traditional stories from across the world, are published today in Springer’s journal Human Nature. The work is of interest because research to date has focused on the problems warfare poses for men, and how these problems shaped human male cognition.
Scalise Sugiyama studied a sample of forager and forager-horticulturalist societies by looking at archaeological and ethnographic research on lethal raiding. This helped her to compile a list of five ‘fitness costs’ – ways in which warfare impedes women’s chances of surviving and reproducing. These occur when a woman is killed, a woman is captured, her offspring is killed, a mate is killed or captured, or an adult male kinsman is killed or captured.
The study then reviewed traditional stories about lethal raids that had been handed down for generations by word of mouth. Scalise Sugiyama analyzed a cross-cultural sample of war stories from 45 societies and found that the five fitness costs often feature within these story lines. The war stories included tales from various North American Indian tribes, the Eskimo of the Arctic, Aborigine groups of Australia, the San of Southern Africa and certain South American tribal societies.
Based on the fitness costs documented in these stories, Scalise Sugiyama believes that ancestral women may have developed certain strategies to increase their odds of survival and their ability to manage their reproduction in the face of warfare. These include manipulating male behavior, determining whether the enemy’s intent was to kill or capture them, and using defensive and evasive tactics to sidestep being murdered or to escape captivity. Assessing the risk of resistance versus compliance also requires having several sets of knowledge. This includes information about an enemy’s warfare practices and how they treat their captives.
The so-called Stockholm Syndrome, in which hostages bond with their captors, could have ancestral roots, hypothesizes Scalise Sugiyama. It often occurs under conditions of physical confinement or physical, sexual, and/or emotional abuse, which are characteristic of captivity in ancestral forager and forager-horticulturalist groups. This response could have developed as a way to help captives identify and ultimately integrate with enemy groups. This then motivates acceptance of the situation and reduces attempts to resist the captor – which may ultimately increase a woman’s chances of survival.
“Lethal raiding has recurrently imposed fitness costs on women. Female cognitive design bears reexamination in terms of the motivational and decision-making mechanisms that may have evolved in response to them,” says Scalise Sugiyama.
- CBA History
- Support Us
- Group Publications