Expectations in the Preservation of DNA & Bacterial Organisms in Differential Montana Burials

This doctoral dissertation project, conducted at the University of Montana’s Lubrecht Experimental Forest, delves into the critical question of how burial methods and shifting climatic conditions influence the way DNA breaks down, investigating how differential burials and climate affect the skeletonization process and preservation of DNA in postmortem cadavers, including the effects of bacterial organisms. Specifically taking place in a region lacking in research and where diverse conditions affect the decomposition process greatly, the Rocky Mountains. This is also relative to the lack of research on DNA and microbes found in soil within the forensic context and the effects of natural mummification, which is heavily prevalent in more arid regions. Through examination of degradation rates of DNA in hard tissue, soft tissue, and topsoil composites across three pig cadaver sites over a year, this study builds upon existing research on decomposition scales and Accumulated Degree Days (ADD). The outcomes promise to provide a comprehensive insight into the intricate interplay between decomposition rates, the progression of desiccated tissue, microbe soil spread, and DNA preservation. The objective of this project is to provide a probative DNA and bacterial display value based on the observational display of decomposition prior to the use of destructive extractions. Preliminary results show that oxygen flow may play a role in a slower decomposition rate for remains buried deeper.