Climate change could have affected the movement patterns of human groups from two cultures that defined the Upper Palaeolithic of Europe: the Gravettian, from c. 30,000 to 20,000 years BP, and the Epigravettian, from c. 20,000 to 8,000 years BP. This is what emerges from a new analysis carried out on several teeth found in the Paglicci Cave, an important site rich in Palaeolithic finds that is located in Rignano Garganico, in the southern Italian province of Foggia.
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| The fourteen teeth found in the site of Grotta Paglicci [Credit: Università di Bologna] |
While the Gravettians, who lived during the Last Glacial Maximum, had permanent settlements and moved away from the area in which they lived only for short periods of time, the Epigravettians, who lived during the interglacial period, moved more frequently and for longer periods. Researchers have used innovative analysis techniques to reach this conclusion – published in Nature Ecology & Evolution – capable of identifying the different geological zones in which individuals have lived, starting from particular elements present in their dental enamel.
The Gravettian is a Palaeolithic culture that spread throughout much of Europe between 30,000 and 20,000 years ago during the last ice-age, and then disappeared during the Last Glacial Maximum, the period of the greatest expansion of the ice. It was replaced by new cultures, such as the Solutrean, which was widespread in the Franco-Iberian area, or the Epigravettian, of which traces can be found in Italy.
At present it remains unclear what, if any, connection there exists between the Gravettians and the subsequent cultures, but the differences that have been observed suggest that the climatic changes that occurred during the last Ice Age may have played an important role in shaping the development of European populations during the last phase of the Palaeolithic.
From recent genetic analyses of some findings, for example, we know that there are correlations between the Epigravettians and other populations living in the Near East: a fact that suggests possible waves of migration from the east to the Italian peninsula after the peak of the last Ice Age.
A step forward to better understanding the differences in lifestyles of these cultures can be found thanks to the analysis of fourteen teeth found in the Apulian site of Grotta Paglicci. Of these, eleven belonged to Gravettians and are dated between 33,000 and 31,000 years ago, while the other three, dated between 20,000 and 18,000 years ago, are attributable to Epigravettian individuals.
The findings were investigated from a chemical point of view through new analytical techniques that focus in particular on the isotopic relationship of strontium in dental enamel.
“Strontium is a component of rocks that, thanks to surface alteration, enters the soil, water and finally the food chain, fixing itself in the bones and teeth of animals and humans,” explains Federico Lugli, a researcher at the University of Bologna who led the study.
“By observing the relationships between particular isotopes of strontium present in the teeth and bones of an individual we can then identify the geological area in which that individual lived.”
From the data collected by these analyses, the researchers were able to reconstruct how often and where the Gravettian and Epigravettian human groups that lived in the area of the Paglicci Cave at different times had travelled.
“The Gravettians were mostly local and travelled far from the ‘base camp’ only for short periods, perhaps in search of food,” says Federico Lugli. “The Epigravettians, on the other hand, moved differently, periodically frequenting areas far from Paglicci”.
To explain this difference in behaviour, the researchers cite the climatic changes that occurred in that period of transition during the last Ice Age. “One of the reasons for this difference in mobility”, continues Lugli, “could be related to the global climate change that occurred between 33,000 and 18,000 years ago, when we went from an Ice Age to an Interglacial Age. A conclusion that, as already suggested by genetic analyses carried out on different finds, highlights the diversity between Gravettians and Epigravettians: two distinct groups with distinct habits of life, including mobility.”
