Archaeology The issue at hand with respect to Olmec pottery relates to the chemical composition of the pottery sherds, and the implications that these chemical compositions have for the trade of pottery among the people of the Mexican highlands. There are two positions posited in the readings, and Sharer (2006) does a good job of explaining the issue. All of the researchers use instrumental neutron activation analysis (INAA) to determine the chemical composition of the sherds. At issue is the interpretation of the INAA results and the extrapolation of those results into findings about trade patterns. On the first point, Sharer (2006) notes that "it has long been acknowledged that INAA leadsto chemical composition groups." The two camps arguing take different interpretations of this, with one camp taking a broader view with respect to the potential number of materials and the other group interpreting the INAA results in a more specific way.

These interpretations are only the first part of the debate. The researchers are seeking to determine things about the way that the Olmec lived from these sherds. Blomster (2005) argues that in the absence of gray or kaolin white sherds, the Olmec did not trade pottery with other nearby cultures. Sharer (2006) instead supports the arguments put forth by Stoltman (2005) that such conclusions cannot be obtained from the basic sherd INAA analysis. Part of the concern lies with the fact that only seven sherds were studied, and these are hardly a representative sample of Olmec pottery, and grossly insufficient from which to extrapolate information about Olmec trading patterns.

The authors were both studying pottery sherds, and using INAA as their technique to determine the underlying chemical composition of the sherds. The dispute itself was about the interpretation of the findings and subsequent extrapolation about Olmec culture. INAA analysis itself is a technique that examines molecular structures to determine chemical composition. Stoltman (2005) also relies on petrographic evidence in the formulation of his arguments, as these remove reliance on chemical composition and focus analysis on study of the actual minerals involved, rather than their neutrons. Stoltman (2011) continues to rely on this technique to support his hypotheses about Olmec pottery.

The two techniques reveal different things about the pottery. Neutron activation seems to be more scientific in nature, but is argued to be less precise. Petrographic evidence is viewed by its proponents as a more complete analysis of the pottery, not just relying on a single line of analysis that reveals only a partial look at the pottery.

Another key element in the debate is logic and ego. The two sides have a disagreement, and the way that they write about it (Neff, 2006; Sharer, 2006) contains thinly veiled jabs at the professionalism in particular of Blomster. There is little doubt that ego is involved here, and the sides both feel that they are using the best technique. There is palpable anger in Neff's and Sharer's writing, taking offense with the conclusions that Blomster has published, as they feel that those conclusions are simultaneously premature and false. Part of this is because they feel that Blomster has not recognized the limitations of INAA as an analytical technique and therefore used it to make extrapolations about trade that cannot be made with that technique, but doubtless they were stung by the fact that he published something that was contrary to their own findings, and did so in a reputable journal. This is not just a dispute about technique.

Ultimately, the two techniques are different, and could lead to different conclusions, but one must take caution in overextending one's logic. Sample sizes must be large enough, and multiple analysis techniques can be used as well. Further, one must be careful of what specific evidence signifies -- a few shards is by no means sufficient to deliver a certain conclusion...

Monte Alban was an important center of the Zapotec people in the highlands of present-day Oaxaca. The Zapotecs were one of many people to inhabit this general region, which is Joyce (2009) notes remains highly diverse to this day. The city was established around 300 BCE, and quickly became the largest center in the area. Its size helped its rulers consolidate their power in these highlands, but there remained from time to time different rivals for power. One of the most important rival cities of the Monte Alban era was Teotihuacan, which emerge around 200 CE. The emergence of Teotihuacan acted as a check on Monte Alban's expansion outside of the valley. Teotihuacan was located in the valley of Mexico, but its influence stretched to what is the Mixtec Alta, a highland area to the northwest of Monte Alban that sat between the two major cities.
These two major centers never reached a state of war, and both collapsed of their own accord, gradually in the case of Monte Alban, and that brought about the resolution of the rivalry, and altered the Mesoamerican political power structure considerably. As for conquest by Monte Alban, Joyce argues in his book Ancient Mesoamerican Warfare (2003) that the lower Verde was incorporated into Monte Alban, on the basis of "epigraphic interpretations and similarities in ceramic styles. The transmission of different pottery is usually seen as conquest in this region, as typically that was the only way to secure trade routes.

13. Cowgill (2008) notes that Teotihuacan flourished from around 100 BCE to 550 CE but provides little hypothesis as to how and why it began to expand. It was known that there were multiple ethnic areas, and that perhaps an influx of foreigners may have reflected change in their homelands to spur emigration. The city seems to have begun its growth with the development of a sophisticated irrigation system and improvements in cropping, which naturally would have allowed more people to survive in this area (Gomez-Chavez, 2012). The introduction of new foods seems to have been a catalyst for at least some of this increased productivity. Gomez-Chavez also provides evidence for large-scale production of goods.

Gomez-Chavez also notes that many of the new arrivals may have been fleeing the changes born of the Xitle volcano eruption. This buried the settlement of Cuicuilco, and caused a movement of peoples around Mesoamerica, and in particular the Mexico valley. Teotihuacan was the sole remaining population center, and attracted not only refugees from the volcano but others who were coming to this area, which with its improved agriculture was becoming more prosperous.

Thus, around 100 BCE there were significant changes that improved the capacity of Teotihuacan to support urbanization, and this in turn spurred the growth of manufactured goods. Trade followed and brought people from other areas of Mesoamerica, in particular what is now Oaxaca and also coastal areas. With many immigrant communities and now the epicenter of population for the people of the Mexico valley, Teotihuacan's growth as a major city was well underway, and the growth process continued for a number of centuries.

11. The three major pyramids at Teotihuacan are the Pyramid of the Sun, the Pyramid of the Moon and the Pyramid of the Feathered Serpent. The Pyramid of the Sun was at the heart of Teotihuacan, but this was not its original name. The name was given to it by the Aztecs, and the original name has been lost. The Pyramid of the Sun is one of the largest pyramids in the world, and was important in terms of being a place for astronomical observation. There is a hollow in the middle of the pyramid, though its purpose is not yet clear. Originally, the pyramid would have been covered in murals, which may have shed more light on the purpose of the pyramid if they still remained. The Pyramid of the…