Dupras Tosha L, Tocheri Matthew W
Department of Anthropology, University of Central Florida, Orlando, FL 32816, USA.
Am J Phys Anthropol. 2007 Sep;134(1):63-74. doi: 10.1002/ajpa.20639.
Studies of infant feeding and weaning patterns in past populations that rely on a cross-sectional approach must make the assumption that no infant mortality bias exists. Previous investigations of infant weaning patterns at the Dakhleh Oasis, Egypt, relied on cross-sectional isotope data. In this study, we re-examine this weaning pattern, using a simulated longitudinal approach, which does not require any assumptions regarding potential infant mortality biases. This involves examining the dental isotopic signatures of individuals who survived the weaning process. Stable isotope signatures from juveniles and adults (102 individuals, 297 teeth) were examined to reconstruct the weaning history of those that survived the weaning process. Both deciduous and permanent teeth were sampled. Homogenized enamel and dentin samples were isolated from each tooth and analyzed for delta(13)C(ap) and delta(18)O(ap) from the enamel and delta(15)N(coll) and delta(13)C(coll) from dentin collagen. We investigate differences between in utero versus postbirth, preweaning versus postweaning, and juvenile versus adult stable isotope values as reflected in the dentition. A random permutation procedure was used to test for statistically significant differences in stable isotope values between tooth types. Statistically significant differences were observed in all stable isotopes between permanent and deciduous teeth, and between early and later forming permanent teeth in delta(13)C(ap) and delta(15)N(coll) isotopes. These results indicate dietary change between in utero and postbirth, and changes occurring during the weaning period. These results provide a more comprehensive picture of infant weaning practices at Kellis and provide further support that complete weaning occurred by 3 years of age.
依赖横断面研究方法对过去人群的婴儿喂养和断奶模式进行的研究，必须假定不存在婴儿死亡率偏差。此前对埃及达赫莱绿洲婴儿断奶模式的调查，依赖的是横断面同位素数据。在本研究中，我们采用模拟纵向研究方法重新审视这种断奶模式，该方法无需对潜在的婴儿死亡率偏差做任何假定。这涉及检查度过断奶期的个体的牙齿同位素特征。研究了青少年和成年人（102人，297颗牙齿）的稳定同位素特征，以重建度过断奶期者的断奶历史。乳牙和恒牙均进行了采样。从每颗牙齿中分离出均质化的牙釉质和牙本质样本，并分析牙釉质中的δ(13)C(ap)和δ(18)O(ap)，以及牙本质胶原蛋白中的δ(15)N(coll)和δ(13)C(coll)。我们研究了牙列中反映出的子宫内与出生后、断奶前与断奶后以及青少年与成年人稳定同位素值之间的差异。采用随机排列程序来检验不同牙齿类型的稳定同位素值之间是否存在统计学上的显著差异。在所有稳定同位素中，恒牙与乳牙之间，以及早期形成与后期形成的恒牙在δ(13)C(ap)和δ(15)N(coll)同位素方面均观察到了统计学上的显著差异。这些结果表明子宫内与出生后的饮食变化，以及断奶期间发生的变化。这些结果更全面地呈现了凯利什的婴儿断奶情况，并进一步支持了到3岁时完全断奶的观点。
