Neanderthals and Chimps and Cave Bears, Oh my!

Eric Trinkaus (1995). Neanderthal Mortality Patterns. Journal of Archaeological Science. 22, 121-142.

In his article, Neanderthal Mortality Patterns, Eric Trinkaus compares the mortality profile of 206 European and Near Eastern Neanderthals with 11 Recent human ethnographic profiles and two non-human species, finding an unusual patter involving too few infants and older adult as well as a very high number of adolescents and prime age adults in the archaeological record.

                  Trinkaus points out three palaeodemographic considerations to be kept in mind when attempting to discover demographic patterns through an examination of mortality profiles. He notes the difficulty of assigning age to any individuals in any society, but reasons that the use of life stage categories in the place of specific ages can mitigate this problem. He appreciates the prospect of sex and age biases generated through the taphonomic process, but adds that comparison to reference samples or demographic models can help to provide relevance. He also acknowledges that variation in demographic regimes can produce lineage affects, but argues that over enough time these distortions should average out. Despite these draw backs to basing demographic interpretations on age-at-death distributions, Trinkaus suggest that insights regarding paleodemographics can still be drawn.

                  Trinkaus employs six age categories to 206 individuals from 77 sites spanning from the Atlantic to Central Asia and from the Levant and Mediterranean Sea in the south to the Crimea and Belgium in the north.  He employs a time scale ranging from the last interglacial to the end of the early last glacial. Assuming that Neanderthals exhibited equivalent rates of maturation as modern humans, Trinkaus employs similar aging techniques in his comparison of this Neanderthal pool with mortality patterns from a set of ethnographic profiles of living ethnographic samples, one including foraging and horticultural groups, another composed of Holocene village foragers or horticulturalists as well as one prehistoric urban sample, and two additional groups of non-human species; Pan troglodytes –our closest relative, and Ursus spelaeus—a large bodied mammal from similar environmental conditions as the Neanderthals.

                  Through comparison of the various profiles, Trinkaus finds that both the non human chimpanzee and care bear patters parallel the Recent human samples, leading him to believe that the Neanderthal pattern should be comparable with Recent human samples. This closer comparison reveals some interesting similarities and variations, as Trinkaus finds that 80% of the individuals in the sample did not reach the age of 40,as well as a very high mortality rate among prime age adults and low number of neonates when compared to Recent human patterns.

Despite Trinkaus’ admission of the many difficulties in translating mortality profiles into paleodemographic data, as well as noting that such pattern may be more of a reflection of differing burial practices, he offers some implications of the study. Neanderthals appear to have had low life expectancies as adult, which in conjunction with the seemingly common phenomenon of healed injuries suggests a difficult life. He reasons that this low life expectancy would need to be countered with a high fertility rare, which would imply a demographic profile at or beyond the limits of Recent human populations (assuming stable population).

                  Trinkaus’ article both offers an interesting and exciting use of data in a creative way and makes very clear the limits of building paleodemographic data on related but indirect indicators in mortality profiles. His attention to the short falls of this extrapolation of data strengthens his credibility in interpreting his findings and suggesting possible implications. The only assumption made by Trinkaus that I felt remained unaddressed was his treatment of Neanderthal as homogenous, monolithic, and static. While acknowledging the distinctness in culture and economy of each Recent human population and how these lifestyles may affect demographics and mortality patterns, he lumps together Neanderthals in an extremely broad geographical area and time scale, offering no justification and making no attempt at consideration of regional differences. I would think that factors such as population pressures, environmental conditions, or even modern regional interests in archaeological research would be important factors in both the influence over and reconstruction of demographic profiles.