Department of Anthropology, University of Nebraska-Lincoln, Forensic Sciences Degree Program, University of Nebraska-Lincoln
Saturday All day, Park Concourse
The degree to which captive and wild chimpanzees differ in various aspects of growth, particularly within the context of construction of growth norms for interpretation of fossil hominin life history, is a contentious issue. Past research has reported growth differences between the two; however more recent work demonstrates a substantial degree of overlap in at least dental growth. Previous studies on tooth growth largely focus on the permanent dentition of Pan troglodytes. This project examines the growth pattern of the mixed deciduous and permanent dentition in juvenile P. troglodytes in order to capture the potentially unique interactions between the two sets of teeth.
Dental x-rays were obtained from total of 110 wild-caught and 66 laboratory-reared juvenile P. troglodytes. All permanent and deciduous teeth were scored according to 10 point scale after Demirjian (1973), Kuykendall (1996), and Fanning (1961) that accounts for deciduous tooth root resorption and exfoliation in addition to growth of all teeth. Results obtained from data on development patterns indicates that in addition to exhibiting greater variability and increased occurrences of sequence polymorphisms overall, wild-caught P. troglodytes differ from their laboratory-reared counterparts in at least three ways: 1) they complete deciduous tooth growth later 2) they initiate deciduous tooth root resorption later and 3) exfoliation of deciduous teeth occurs later in the overall sequence than in their laboratory-reared counterparts. These results indicate the usefulness of methodologies that incorporate information on the mixed dentition as a whole in teasing out the finer differences of dental development between populations.
This research was funded by The Leakey Foundation