Variations in dietary patterns in the ancient Greek colony of Abdera: insights from isotopic evidence and bayesian modeling

Abstract Abdera is an ancient Greek colony in northern Aegean. It exhibits a unique foundation history as it was first established in 654 BC by the Ionian city of Klazomenae and in 545 BC by the city of Teos. The first colonial endeavor failed due to harsh living conditions and conflicts with local populations. Exposed to unfamiliar challenges, the settlers faced physical strain and maladies, particularly affecting the subadults, who were deprived of proper care and nutrition during critical periods of life. After about a century the city of Teos colonised Abdera under the pressure of the Persian attacks. The new colonial endeavor was successful, and the city managed to capitalize on its natural resources, flourishing through the centuries. This study reconstructs the diet of 109 adults and subadults from Abdera dating from the Archaic through the Roman times (654 BC–400AD) using stable isotope ratios of carbon (δ13C), nitrogen (δ15N) and sulphur (δ34S) from bone collagen. Bayesian modeling was implemented to quantify the relative consumption of different food sources in Abdera and compare it with other contemporary sites. Weaning duration was estimated to investigate the nutritional and health status of infants that is believed to have affected the fitness of the population in the long run. Our results indicate that the first settlers of Abdera primarily relied mostly on local resources such as terrestrial C3 plant and fish resources, complemented to a lesser extent by animal protein and millet (C4 plant). This pattern persisted over time. However, Bayesian modeling indicated different levels of food access on an individual level and variations in consumption patterns between other contemporary populations of ancient cities. Weaning during the first colonization phase began around nine months whereas during the Roman period weaning started earlier, around four months. In both cases weaning was completed around the age of six years old. The sulfur analysis revealed that females were not local but migrated to Abdera especially during the first colonial phase. Our study highlights the significance of diet as a key lens for studying the trajectory of a settlement, and a key factor for understanding the growth, the resilience, and the cultural evolution of the ancient Greek colonies.