The lives of Native Americans changed in dramatic ways after Christopher Columbus landed in the Caribbean in 1492. Written records paint a vivid picture of conquest and epidemics sowing death and disease among the indigenous peoples of the Americas, quickly decimating them. Until recently, in fact, almost all that was known about the biological consequences of contact with the Europeans was based on these old documents, which emphasize epidemics and population collapse. These texts offer an important perspective, but they are not the only source of information.
Bioarchaeology, an emerging field that focuses on the study of archaeological remains, is supplementing our view of the health and daily life of Native Americans, particularly those who lived in the Spanish missions of the Southeast, in an area once known as La Florida. Sustained encounters between Indians and Europeans in La Florida began in 1565, when Pedro Menndez de Avils established the town of St. Augustine on the Atlantic coast in northern Florida. From there Roman Catholic priests set up a chain of missions among the Timucua and Apalachee Indians of northern Florida and the Guale Indians of the Georgia coast. At some of those places--including Santa Catalina de Guale on St. Catherines Island, San Martn de Timucua and San Luis de Apalachee--archaeologists have uncovered the ruins of large churches that served the converts. As the nucleus of each community, the church carried out important religious functions for the living; for the dead, it provided a burial ground.
Skeletons found beneath the floor of these churches have a surprisingly complete record of the diet and work habits of the mission Indians. Bioarchaeology is beginning to fill in the details of the historical record, offering specifics about how food sources changed and raising unexpected questions about the merits of a purely agricultural way of life--at least for the Indians who inhabited La Florida.
Before our research, the diets of La Florida Indians were reconstructed from two sources: accounts by priests and other Europeans, and food remains at archaeological sites. The written records are often contradictory. Some depict little farming at the time. Others say that indigenous peoples relied heavily on agriculture, particularly on corn.
The archaeological record is inconclusive as well. Plant remains do not always survive well, and in coastal regions they are particularly vulnerable to the destructive effects of moisture and acidic soils. Nevertheless, analysis of such evidence has revealed that native peoples ate numerous plant species, both wild and domesticated, before and after the arrival of the Europeans. But their use of corn is unclear. Excavations have revealed some kernels and cobs from late prehistoric and contact-era sites; however, the relative importance of this grain in the Indians diet is not known.
TO RESOLVE some of these questions, we turned to the many bones found at these sites. Because the tissues of all living things contain stable isotopes of such elements as carbon and nitrogen, we can measure the amounts of these elements in bones and then use this information to reconstruct ancient diets. Differences in the ratios of two carbon isotopes, carbon 12 and carbon 13, contain a record of which plants an individual ate. Most plants are divided into two types: carbon 3 plants break down a three-carbon molecule during photosynthesis; carbon 4 plants synthesize a four-carbon molecule. The distinctive chemical signature of the C3 and C4 plants that a person consumes shows up in his or her bones. Virtually all plants eaten in the La Florida region were of the C3 variety--including fruits, wheat, acorns and hickory nuts. The only major C4 plant eaten by native peoples was corn.
Nitrogen isotopes provide a different set of clues. Fish bones and oyster shells in archaeological sites indicate that the Guale and other native peoples of the region ate seafood regularly--before and after the Europeans arrived. Because marine plants, such as algae, and terrestrial plants use the two stable isotopes of nitrogen--nitrogen 14 and nitrogen 15--differently, the ratios of these isotopes are distinct in the bones of a person who ate mostly marine foods as opposed to one who ate mostly terrestrial foods.