Paleofeces

Paleofeces (UK: Palaeofaeces) are ancient human feces, often found as part of archaeological excavations or surveys. The term coprolite is often used interchangeably. Intact feces of ancient people may be found in caves in arid climates and in other locations with suitable preservation conditions. They are studied to determine the diet and health of the people who produced them through the analysis of seeds, small bones, and parasite eggs found inside. The feces can contain information about the person excreting the material as well as information about the material itself. They can also be chemically analyzed for more in-depth information on the individual who excreted them, using lipid analysis and ancient DNA analysis. The success rate of usable DNA extraction is relatively high in paleofeces, making it more reliable than skeletal DNA retrieval.

The reason this analysis is possible at all is due to the digestive system not being entirely efficient, in the sense that not everything that passes through the digestive system is destroyed. Not all of the surviving material is recognizable, but some of it is. This material is generally the best indicator archaeologists can use to determine ancient diets, as no other part of the archaeological record is as direct an indicator.

The process that preserves the feces in a way such that they can be analyzed later is called the Maillard reaction. This reaction creates a casing of sugar that preserves the feces from the elements. To extract and analyze the information contained within, researchers generally have to freeze the feces and grind it up into powder for analysis.

Analysis of archaeological feces has a relatively short history compared to many other archaeological materials. The founder of the discipline is Dr. Eric O. Callen, who pioneered the subject in the late 1950s to mid-1960s. His early papers used coprolite analysis to investigate early Mexican diets, published in The Prehistory of the Tehuacan Valley: Environment, and Subsistence. Despite his work showing promise, archaeological coprolite studies remained a niche topic, with few other researchers becoming involved. After Callen's sudden death in 1970, his work was continued by Vaughn Bryant at Texas A&M University, Department of Anthropology. Coprolite analysis gradually became a topic of serious study. Today coprolite analysis in archaeology has increased exponentially, and they have provided important evidence concerning the evolution of human health and diet, in the Americas and other parts of the world. One of the most famous examples is the coprolite from Paisley Caves, Oregon, which has provided some of the earliest evidence for the human occupation of North America.

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