The life-history of a late Mesolithic woman in Iberia: A sequential multi-isotope approach

Multi-isotope analyses on diverse body tissues can offer valuable information on individual life-histories at different temporal resolutions. Here, we reconstruct the diet and mobility of a Late Mesolithic (ca. 5500 cal. BC) young woman buried in Aizpea rockshelter (Navarre, north-central Iberia). To this end, we combine δ13C and δ15N isotope analyses of bone collagen, together with sequential δ13C and δ15N isotope analyses of tooth dentine and 87Sr/86Sr analysis of tooth enamel from the permanent maxillary right second molar. We also present results of bone collagen measurements for a wide range of coeval faunal remains, including terrestrial ungulates, freshwater fish and birds, and plant remains (i.e. carbonized pome fruits and hazelnut shells) to characterize baseline isotopic signatures. Results suggest a broad-spectrum diet with a relatively high and stable protein intake during early childhood and significant changes in diet during late childhood, including two marked dips in δ15N at 8.5 and 11.5 years old, and a progressive decrease in δ13C and δ15N from adolescence onwards. The dips may relate to metabolic processes related to growth or, more probably, to age-related subsistence practices, particularly supplementation by children of the parentally provisioned diet, while the sustained drop in isotope values may be associated with a progressively higher dietary contribution from plants that extends into adulthood. Strontium isotope data support relatively restricted mobility from age 2.5 to 8 (i.e. the approximate time-span covered by enamel formation in the permanent maxillary second molar), consistent with the high degree of territoriality attributed to the last hunters-gatherers in northern Iberia