An a-maize-ing find Archaeologist examines teeth to uncover mysterious Oneota agriculture shift Robert Jeske, an archaeologist and professor of anthropology at UWM, knows that our teeth tell a story: What we eat, our overall health, and the kinds of crops we cultivate. His most recent paper details how his coauthors and he used dental remains to uncover the agriculture trends and diet of Wisconsin’s Oneota settlements, groupings of Native Americans who lived in clusters around the state more than a thousand years ago. His research adds evidence to a surprising development in history: Around 1000 AD, Native Americans made a drastic shift in their diets to include more maize, and no one knows why. Jeske sat down to talk about his research, which was published in the American Journal of Physical Anthropology earlier this year. What was the main focus of your research? The basic idea is that people who live in different environments, you might suspect, have different ways of making a living. We’ve been looking at how people began to use maize agriculture in Wisconsin. Many researchers assumed that you’d have a lot more maize down south than you would up north. In between here and Oshkosh is a transitional area where we go from savannah and prairie and mixed forest to more of a forested environment. That forest goes from a dry forest up to the wet forest that you see in northern Wisconsin. We thought maybe there would be difference between how much agriculture people south of that transition would do as opposed to people north. When we looked at that, it turns out that probably not. Based on the dental characteristics we see from people south and north of that line, they seem to be engaging in agriculture at about the same rates. So, the assumption was that people in these separate locations would have different agricultural practices because of their different environments?
6 • IN FOCUS • December, 2019
Maize is a Mexican domesticate. We assume that it took time to spread from the south up to the north. Now what we’re finding is that that doesn’t appear to be the case. In fact, the amount of maize that people ate switched at about AD 1000 from being a relatively small part of the diet – probably less than 25 percent around 800 AD – to being more than 50 percent of the diet by 1100-1200. And everybody, throughout the Midwest and the Great Robert Jeske Lakes, appears to switch over at the same time, regardless of the actual environment that they’re in. Whether you’re down in the Ohio River Valley, which is much warmer than here, or up in the Fox Valley, which is much colder than here, or you’re out in Lake Koshkonong or down in northern Illinois, everybody seems to switch at about the same time. And we can tell this because we look at their teeth. How does looking at teeth tell you people made a huge shift in their diets to maize? If you go back a thousand years and look at teeth, you’ll see they’re ground flat because they tend to have a fair amount of grit in their diet, but they tend to be very healthy. And you don’t have much in the way of caries or cavities. After AD 1000, you get teeth falling out. You get abscesses. And you get great big cavities in large numbers of teeth. The cavity per tooth count goes way up. And it’s because of a sudden switch to maize as the major food source in the diet.
