Function and form of teeth in human evolution
Some of the most noticeable changes in the evolution of the genus Homo (which includes ourselves and our extinct close relatives) have been in the dentition and the jaws which support them. In general, living people have smaller teeth and less robust jaws than people living 25,000 years ago. Neanderthals, from perhaps 120,000 and becoming extinct in Europe after 30,000 years ago, had particularly large incisor and canine teeth, together with a number of other unique dental features. The oldest British hominin fossil teeth, at about 500,000 years ago, from the Boxgrove site in Sussex, were larger still. In order to understand such differences, it is important to see the teeth in a context of their use during life.
One of the characteristic features of all archaeological teeth from site antedating the large cities from the 18th century onwards is very heavy wear. This is particularly true of remains from pre-agricultural contexts where, by a stage of skeletal development which today would be reached at early middle age, many teeth were already worn down to the roots. Wear on this scale is virtually unknown to modern dentistry. It is therefore poorly understood.
The research team have been able to work with dental impressions, taken by dentists during the mid-20th century, of the teeth of hunter-gatherers who had led a traditional life in which their teeth wore down rapidly. These include Inuit and Australian aborigine people whose ages were recorded at the time the impressions were made. This has made it possible to understand both the rate of wear and the pattern of wear between different teeth in a way that allows us to interpret the pattern of wear in dentitions from Neolithic, Mesolithic and Upper Palaeolithic context. It has also allowed us to make a special study of the Neanderthal dentition.
The Boxgrove lower incisor teeth are a particularly interesting case for study, because they have a unique pattern of polishing down the whole of the crown and root on the side that would have faced the lips.
- Clement, A.F., Hillson, S.W., Aiello, L.C. Tooth wear, Neanderthal facial morphology and the anterior dental loading hypothesis. Journal of Human Evolution, 62 (3), 2012, 367-376.
- S. W. Hillson, S. A. Parfitt, S. M. Bello, M. B. Roberts, and C. B. Stringer. Two hominin incisor teeth from the middle Pleistocene site of Boxgrove, Sussex, England. Journal of Human Evolution 59, 2010, 493-503.
- C. M. Fitzgerald and S. W. Hillson. Alternative Methods of Assessing Tooth Size in Late Pleistocene and Early Holocene Hominids. In: Technique and Application in Dental Anthropology, edited by J. D. Irish and G. Nelson, Cambridge: Cambridge University Press, 2007, p. 364-388.
- E. Trinkaus, S. W. Hillson, R. G. Franciscus, and T. W. Holliday. Skeletal and dental paleopathology. In: Early Modern Human evolution in Central Europe, edited by E. Trinkaus and J. Svoboda, Oxford:Oxford University Press, 2005, p. 419-458.
- S. W. Hillson, R. G. Franciscus, T. W. Holliday, and E. Trinkaus. The ages at death. In: Early Modern Human evolution in Central Europe, edited by E. Trinkaus and J. Svoboda, Oxford:Oxford University Press, 2005, p. 31-45.
- S. W. Hillson, C. M. Fitzgerald, and H. M. Flinn. Alternative dental measurements – proposals and relationships with other measurements. Anonymous. Anonymous. American Journal of Physical Anthropology 126:413-426, 2005.
- S. W. Hillson. Dental morphology, proportions and attrition. In: Early Modern Human evolution in Central Europe, edited by E. Trinkaus and J. Svoboda, Oxford:Oxford University Press, 2005, p. 179-223.
- Leverhulme Trust