The archaeological and ecological applications of faecal biomarker analysis
Human impacts on the planet are often associated with European colonialism and the Industrial Revolution. However, a narrow focus on these recent changes overlooks the time-depth and variety of human ecosystem transformations in the past, particularly in relation to animal herding and domestication, cultivation, the emergence of dense sedentary, and even urban settlements, and their impacts on diverse landscapes.
Searching for major thresholds of human impacts on earth systems in the past has been hindered by a lack of suitable markers of anthropogenic change that can be applied globally. Interlinked with the ‘Global Markers of the Anthropocene’ project led by Dr. Nicole Boivin, we are developing the application of human and animal faecal steroid biomarker analysis, from archaeological and natural sediment accumulations, as a qualitative method for understanding shifts in human presence and environmental impacts.
Measurement of changes in the concentrations of faecal biomarkers, specific to humans and different animals, preserved in sedimentary records are being increasingly used to determine the presence of different taxa and their palaeodemography through time. Faeces contain unique biochemical tracers that may preserve for millennia under favorable conditions. However, in order to gain better understanding of preservation processes, faecal biomarker transport, and landscape level variation in faecal accumulation it is essential to develop modern baselines for specific geographical, climatic, and anthropological contexts. Much of this baseline work is yet to be done in an anthropological context meaning that interpretations of such proxies in the archaeological record remain tentative. We are currently developing innovative baseline studies in a variety of climatic settings, in close collaboration with a number of diverse local communities, in order to determine how faecal biomarkers are preserved and presented across modern anthropogenic, particularly pastoral, landscapes.
In tandem, we are also beginning to initiate a series of projects that investigate the demographics of wild and domesticated animals in response to human hunting and domestication using faecal biomarkers (bile acids and stanols) recovered from well-dated sediments. We will particularly be applying these methodologies in areas where active archaeological research is being undertaken by the Department of Archaeology, and where we have solid existing contextual knowledge in relation to the presence of hunter-gatherers, pastoralists, and farmers in different regions through time. However, we will also expand our scope based on sample availability and the regional and temporal interests of members of the Department at any given time.