Archaeologists have fiercely debated whether the first civilization in Mesoamerica emerged from the singular influence of one culture or from the exchange of many. Now, a large analysis of ceramics shows that one region--the Gulf Coast Olmec people--exported a definitive style of pottery to everyone else.
When societies were first forming in Mesoamerica, between 3150 and 2800 years ago, a site now called San Lorenzo was the Manhattan of its day. Sprawling across some 700 hectares, it featured monumental pyramids and colossal heads sculpted out of basalt. This so-called Olmec culture came to include a sophisticated calendar, a notion of divine kingship, and ball courts--all of which were incorporated by later cultures like the Maya. Some archaeologists have argued that the Gulf Coast Olmec were the "mother culture" of Mesoamerica. Others think that many societies in the area deserve credit, arguing that regional differences in Olmec ceramics, for example, show that the style was not of a central origin.
A team led by Jeffrey Blomster of George Washington University in Washington, D.C., decided to test this idea by chemically analyzing the pottery. Focusing on seven regions, the team amassed a collection of 725 samples from collaborators at the Universidad Nacional Autónoma de México and elsewhere, as well as hundreds of samples of raw clay from various places.
Chemical analysis confirmed that each region produced ceramics locally, but six regions also imported ceramics from the San Lorenzo area. In contrast, the team reports in the 18 February 2005 issue of Science, the Olmec in San Lorenzo did not import any ceramics. "They seem to be the synthesizers, creators, and exporters," says Blomster, not just of ceramics, but of the cultural ideas associated with the pottery motifs.
Critics aren't convinced. "The spread of iconographic motifs certainly does not prove the claim that the Olmec also disseminated social, political, and religious institutions to those they were trading with," says David Grove of the University of Florida, Gainesville. And Kent Flannery of the University of Michigan disputes that the Olmec weren't importing pottery from elsewhere. "It is simply not true that nobody else's ceramics show up at San Lorenzo."
But Richard Diehl of the University of Alabama, Tuscaloosa, says the "groundbreaking" study demonstrates that the spread of ideas was not a two-way street. "It shows that San Lorenzo was by far the dominant center during this early formative period."