Date of Award


Degree Type


Degree Name

Master of Science




Biology (MS)

First Advisor/Chairperson

Josh Sharp


This research presents the findings from a study that involved assessment of the changes in the necrobiome reflected in muscle tissue samples collected from two human donors that were allowed to naturally decompose in differing temperatures over a six-month period. The research questions addressed by this study include whether the biodiversity or the abundance of certain bacteria rises or falls with increasing and decreasing temperatures, and whether or not a bacterial succession pattern could be established. DNA was isolated from the samples derived from muscles in two separate regions of the body, vastus lateralis (thigh) and deltoid (shoulder), and they were sequenced using 16S ribosomal RNA sequencing. The result was filtered using QIIME2 and analyzed using R/RStudio. This study found that in one donor, biodiversity of necrobiome communities increased with rising temperatures and decreased with falling temperatures, while the bacterial abundance decreased during this time. The increase of biodiversity with increasing temperatures also occurred during a transition from laboratory conditions to environmental conditions and could have played a role. The other donor in this study demonstrated an increase in abundance and a decrease in biodiversity during the same timeframe. More necrobiome research needs to be done to determine a bacterial succession pattern. The human remains used in this study were donated voluntarily to the Northern Michigan University Forensic Research Outdoor Station (FROST) through the NMU Body Donation Program.

Access Type

Open Access

Justification for Restricting Access

The worked contained within the thesis will be submitted for publication in a peer reviewed journal by 11/15/25. The embargo is required to protect the data so that no one else can copy Callan Herst's original work and publish it. Additionally, some journals require that the data submitted can not published elsewhere prior to submission to their journal. Publication in the NMU Commons could violate that condition.

Available for download on Tuesday, November 14, 2028