Estimating the Number of Individuals in a Large Commingled Assemblage

Abstract

Estimation of the number of individuals in an assemblage is critical to determine the scale of an incident and whether all expected individuals have been accounted for. However, estimates are affected by recovery and other taphonomic factors inherent to the assemblage, as well as the estimation methods themselves. This study examines several quantification methods using data from the commingled remains of individuals who were aboard the USS Oklahoma at the time of its sinking. Alternatives to traditional minimum number of individuals (MNI) quantifications are presented, to include MNI by duplicated elements per mitochondrial DNA (mtDNA) sequence and use of the zonal inventory procedure. These methods are assessed to determine which provides an estimate closest to the expected population size. Potential advantages and limitations associated with each method are discussed. For this assemblage, a combination of mtDNA sequencing using hypervariable regions 1 and 2 (HV1, HV2) and element duplication provides the most accurate estimate of individuals, and methods that employ pair-matching perform better than those that do not.