EAGER: Environmental DNA in unfrozen archaeological sediments--testing the results
Human use of natural resources is a critical component for understanding human prehistory. Various well-established methods such as bone and plant identification shed light on past resource use. However, short-comings such as difficulties in identification and biases in these data can yield to an incomplete picture of human activity. Ancient DNA extracted from archaeological sediments can address these concerns. However, poor preservation of the ancient DNA in sediments that are unfrozen for part of the year maybe problematic. This cutting-edge study will test the reliability of ancient DNA analyses from unfrozen sediments by comparing those results with contemporaneous well-preserved ancient DNA as well as with conventional plant and animal identifications. Resource availability and its use by humans in central Alaska between ca. 14,000 and 5,000 years ago is important as this is a critical region and time period in human prehistory. First, humans initially entered North America by way of central Alaska and the region is a cultural and environmental nexus between the old and new worlds. Second, the climate was very dynamic during this period as the world transitioned from glacial to modern conditions. In Alaska, this meant the spread of the forest, expansion, extinction, and/or redistribution of game animals (such as elk, bison, and moose), and establishment of salmon streams. Shedding light on the availability of resources and whether people harvested them is critical to understanding past human behavior in central Alaska. In this study, ancient DNA results will be rigorously analyzed to assess for biases resulting from sediments that are unfrozen for four months of the year. A system of blanks and controls will shed light on any contamination issues and comparison with ancient DNA extracted from contemporaneous lake sediments, where preservation is known to be good, will address whether poor DNA preservation is also a concern. This project has the potential to revolutionize our understanding of past landscapes and human use of that landscape.