Estimating weaning and early childhood diet from serial micro-samples of dentin collagen

Stable isotope analysis of serial samples of third molars as insight into inter- and intra-individual variation in ancient diet

“…For first molars, which grow between age 0 and 9, we can capture important dietary changes early in life, such as weaning (e.g., Eerkens et al, 2011). For third molars, which grow largely during the second decade of life (ages 9-21), we can examine changes in diet as individuals are transitioning into adulthood.…”

“…As a result, it is possible to isolate sections of teeth and determine their stable isotope composition (e.g., Beaumont et al, 2012Beaumont et al, , 2015Burt, 2015;Eerkens et al, 2011;Fuller et al, 2003). This facilitates tracing of certain aspects of diet over the window in which that section grew.…”

“…Sample preparation followed procedures established in Eerkens et al (2011) for first molars. Teeth were cleaned with a small brush of any adhering soil or other exogenous material, sonicated in deionized water (dH 2 O), and cut in half longitudinally (i.e., crown to root) with a slow-speed diamond-coated saw.…”

“…Note that these cuts are generally parallel to growth layers within the crown, but cut across diagonal growth layers in the root (see Eerkens et al, 2011). Because layers accumulate in a cone-like manner within the root, we are unable to manually cut cones out of the demineralized root, but must cut horizontally across growth planes.…”

“…Yet, such individual-scale analyses are better suited for testing hypotheses drawn from evolutionary theory in anthropology, which focus on the actions of individuals, not groups of people. Even fewer studies in archeology focus on variation in diet over time within particular individuals, though recent studies on hair and teeth have attempted to address this issue (Beaumont et al, 2012;Burt, 2015;Eerkens et al, 2011Eerkens et al, , 2014aFuller et al, 2003;Sharp et al, 2003;Webb et al, 2013).…”