Isotopic evidence of weaning in huntergatherers from the late holocene in Lake Salitroso, Patagonia, Argentina

TESSONE, A.; GARCÍA GURAIEB, S; GOÑI, R. A.; PANARELLO, H.O.

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2015

0002-9483

ABSTRACT  Objectives: The timing and duration ofbreastfeeding and weaning in past hunter-gatherer populations are discussedbased on the results of stable carbon and nitrogen isotope analyses undertakenon a Late Holocene skeletal sample from Lake Salitroso in the Patagonian steppe(Argentina). Research in Lake Salitroso is part of a regional project thatstudies the relationship between hunter-gatherer societies, theirorganizational systems and the environmental changes during the last 3,000years in Patagonia. Methods: The sample included 52 individuals: 33 subadults and19 adults of both sexes. They were recovered from 24 burial stone structures locallycalled chenques, with dates ranging from ca. 800 BP to 350 BP. Ribs wereselected for collagen extraction and measurement of 13C/12C and 15N/14N ratios. Results: A d13C mean value of -21.87 ± 6.05permil was obtained, with a range between -21.98  permil and -21.71 permil,whereas d15N recorded a mean of 11.9 permil 6.1 permil with a range between10.1 permil and 14.8 permil. d15N data showed an age related pattern withparticularly marked difference between values for subadults under the age of 4and older individuals. As opposed to d15N, d13C showed little variation withage. Conclusions: An early incorporation of supplementary solid food between0.75 and 2 years of age and a late cessation of breastfeeding at about 5 to 6years of age were inferred. This suggests that among this Patagonian hunter-gathererpopulation weaning was a gradual and lengthy process. These results areconsistent with the patterns observed in cross-cultural studies andarchaeological samples of hunter-gatherer groups.