Author's School

Graduate School of Arts & Sciences

Author's Department/Program



English (en)

Date of Award

January 2010

Degree Type


Degree Name

Doctor of Philosophy (PhD)

Chair and Committee

Fiona Marshall


This research was designed to test Tchernov's model of commensalism and the idea that remains of commensal species that today coexist with humans in settlement environments could be used to detect early sedentism in the archaeological record. The validity of the model has been questioned due to the lack of empirical knowledge on commensalism in a wide range of settlement environments including sedentary and more mobile ones. This study examined the commensalism model by focusing on seasonally occupied settlements of Maasai pastoralists in East Africa. Methods from ecology, ethnography, and archaeology were used to document the impact of Maasai settlements on associated communities of small rodents and shrews: micromammals), to measure the intensity of human occupation in settlements, and to relate settlement intensity to micromammalian communities. Taphonomic approaches were also used to evaluate the potential for accumulation and preservation of evidence on commensalism in the substrate of the settlements. The results of the study showed that, in contrast to what we might expect in highly sedentary settings, Maasai settlements increased rather than decreased the biological diversity of local micromammalian communities. Along a gradient of increasing duration of human occupation, but continued seasonal use of settlements, there was no manifest increase in the population of any single species that would amount to pronounced commensalism. This supports the commensalism/sedentism linkage but also suggests more broadly that it should be possible to demarcate distinct contexts of commensalism and related levels of biological diversity in relation to varying intensities of site occupation. These results call for greater investment in systematic fine-recovery and study of variability of micromammalian assemblages at archaeological excavations.


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