A number of previous studies have examined biological variability within individual human skeletal samples, using internal chronology as an explanatory source for variation. In this paper time series and matrix comparison methods are used to examine temporal serial correlation and trend of biological characteristics within a skeletal sample. These methods follow appropriately upon the assumption that the processes of genetic drift and migration lead to temporal autocorrelation of the mean genotype within individual genetic lineages. In the current analysis, using skeletal material from the Pete Klunk Mound Group, temporal serial correlation is demonstrated between samples from different mounds. This indicates that a previous provisional archaeological ordering of the mounds is probably correct. Absence of temporal trend for any of the nonmetric traits examined here suggests a lack of directional evolutionary forces operating on these traits.