Detection of breastfeeding and weaning in modern human infants with carbon and nitrogen stable isotope ratios

Carbon ((13)C/(12)C) and nitrogen ((15)N/(14)N) stable isotope ratios were longitudinally measured in fingernail and hair samples from mother-infant pairs where infants were exclusively breastfed (n = 5), breast- and formula-fed (n = 2), or exclusively formula-fed (n = 1) from birth. All exclusively breastfed infants had a dual enrichment in carbon ( approximately 1 per thousand) and nitrogen ( approximately 2-3 per thousand) when compared to maternal values. In contrast, breast- and formula-fed subjects had reduced enrichments compared to exclusively breastfed subjects, and the exclusively formula-fed infant showed no increase in delta(13)C or delta(15)N values. This finding of a carbon trophic level effect in breastfeeding infants suggests that (13)C-enrichments of approximately 1 per thousand in archaeological populations are not necessarily the result of the consumption of C(4)-based weaning foods such as maize or millet. During the weaning process, the delta(13)C results for breastfed infants declined to maternal levels more rapidly than the delta(15)N results. This suggests that delta(13)C values have the potential to track the introduction of solid foods into the diet, whereas delta(15)N values monitor the length of time of breast milk consumption. These findings can be used to refine the isotopic analysis of breastfeeding and weaning patterns in past and modern populations.     

Reconstructing infant weaning histories at Roman period Kellis, Egypt using stable isotope analysis of dentition

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.     

Weaning age among foragers at Matjes river rock shelter, South Africa, from stable nitrogen and carbon isotope analyses

Matjes River Rock Shelter is a large shell midden on the southern coast of South Africa. Stable nitrogen (delta(15)N) and carbon (delta(13)C) isotope ratios were measured in bone collagen and dentine from human skeletons excavated from this site in order to establish a weaning curve in mid-Holocene hunter-gatherers. delta(15)N results show a progressive increase in individuals from birth to 1.5 years old. delta(13)C results are more tightly clustered and mirror the steady progressive change seen for delta(15)N. We deduce that children at Matjes River Rock Shelter were breastfed for at least the first 1.5 years after birth, and were weaned sometime between 2-4 years of age. A similar pattern was documented for historic-era Kalahari foraging people, where the interbirth spacing was approximately 3 years. This study provides the first direct evidence for an extended period of breastfeeding, and thus long interbirth intervals, among prehistoric foragers, even when those foragers lived in an environment with abundant food resources.     

中国古代儿童断奶模式与喂养方式初探——以安徽薄阳城遗址人骨的C、N稳定同位素分析为例

了解古代儿童的断奶模式和喂养方式,可望为揭示古代儿童的营养状况、生长发育以及其死亡原因提供有价值的重要信息。近些年来,通过对古代儿童骨骼的C、N稳定同位素分析,重建古代儿童的断奶模式和喂养方式,成为国际生物考古界的研究前沿,但在我国尚无任何相关报道。为此,本文以安徽滁州薄阳城遗址人骨(包含不同年龄阶段的儿童和成年人)样品为研究材料,通过对同一个体肋骨和肢骨的C、N稳定同位素分析和比较,重点探讨了我国西周时期儿童的断奶模式及喂养方式。研究结果显示:儿童在2岁已有辅食的摄入,大多数儿童在3-4岁已经完成断奶;断奶后的儿童,其食物中包含更多的植物作为辅食。本研究,印证了我国历史文献中有关儿童喂养模式的最早记载(唐代孙思邈的医书《千金方》),也为系统探索我国古代儿童的断奶模式和喂养方式提供了很好的范例。     

Infant feeding and weaning practices in Roman Egypt.

Current knowledge of infant feeding and weaning practices during the Roman period in Egypt is limited to scanty documentary and iconographic evidence. Stable nitrogen and carbon isotope analysis provides another avenue to explore this question. A sample of 49 infant and juvenile human skeletal remains from the Kellis 2 cemetery in the Dakhleh Oasis, Egypt, was used to determine patterns of infant feeding and weaning. delta(15)N values indicate that supplementary foods were introduced at around 6 months of age, and that weaning was complete by 3 years of age. By 6 months of age, delta(13)C values become increasingly enriched over adult values, and reach peak enrichment at approximately 1.5 years of age. Beyond this age, delta(13)C gradually declines to approach adult values. This enrichment in infant delta(13)C values is indicative of consumption of (13)C-enriched supplementary foods. Based on isotopic study of faunal and botanical remains from the ancient village of Kellis, we conclude that at approximately 6 months of age, infants were fed milk of goat and/or cow.     

The petrous bone--a new sampling site for identifying early dietary patterns in stable isotopic studies

Intraskeletal variation in the composition of carbon (delta(13)C) and nitrogen (delta(15)N) stable isotopes measured in collagen is tested from various human bones and dentine. Samples were taken from the femur, rib, and petrous part of the temporal bone from well-preserved skeletons of both adults (n = 34) and subadults (n = 24). Additional samples of dentine from the root of 1st molars were taken from 16 individuals. The skeletal material is from a medieval cemetery (AD 1200-1573) in Holbaek, Denmark. Our results indicate that the petrous bone has an isotopic signal that differs significantly from that of femur and rib within the single skeleton (P < 0.001 and P < 0.001, respectively), with only minor variation seen between femur and rib. On the other hand, there was no significant difference between the petrous bone and the 1st molar. The intraskeletal variation may reflect differences in turnover rate among skeletal elements. The inner periosteal layer of the petrous bone is formed in uterus and does not undergo any further remodelling after the age of 2 years, whereas the rib and femur have a continuous turnover rate of approximately 5 and 10-20 years, respectively. From the results of this study it is believed the petrous bone may be a new useful bone element and a supplement or a proxy for teeth in the analysis of early dietary patterns as it may reflect diet in fetal stages and early years of life.     

Isotopic evidence for breastfeeding and possible adult dietary differences from Late/Sub-Roman Britain

Historical documents indicate that breastfeeding and weaning practices have fluctuated in England through history. In order to obtain evidence for general breastfeeding patterns in Late/Sub-Roman Britain, stable carbon and nitrogen isotope values were measured in juvenile and adult skeletons (n = 87) from the cemetery of Queenford Farm, Dorchester-on-Thames, Oxfordshire. As the site contained few individuals between 0-1.5 years of age, it was not possible to determine the initial timing for the introduction of weaning foods. Between ages 2-4 years, the mean +/- SD delta(13)C results (-20.2 +/- 0.3 per thousand) are significantly more negative (t = -4.03, P < 0.001) compared to adult females (-19.7 +/- 0.3 per thousand). This is interpreted as evidence of a different diet being fed to children during weaning. After age 2, the delta(15)N values gradually decline, indicating complete cessation of breastfeeding by 3-4 years. Among adults, stature (males = 1.68 +/- 0.06 m; females = 1.58 +/- 0.07 m) and sexual dimorphism (106) were low, suggesting that the population was possibly under environmental stress. The delta(13)C results for adults are similar, but females show a small but statistically significantly (t = -2.86, P < 0.01) lower mean delta(15)N value (9.9 +/- 0.9 per thousand) compared to males (10.6 +/- 0.5 per thousand). These lower female delta(15)N values possibly reflect the different physiology of the sexes (pregnancy and/or lactation) or the reduced consumption of animal/fish protein by women, and this may have been influenced by individual preference, family needs, or societal values of the era.     

Dismembering bodies for display: a bioarchaeological study of trophy heads from the Wari site of Conchopata, Peru

This study integrates isotopic, palaeopathological, and historical evidence to investigate infant and young child feeding practices in a Roman period (1st to 3rd centuries AD) skeletal sample from the Isola Sacra necropolis (Rome, Italy). Stable isotope analysis of bone collagen from 37 rib samples indicates that transitional feeding began by the end of the first year and weaning occurred by 2-2.5 years of age. Both delta(15)N and delta(13)C data clearly show the trophic level effect associated with breastfeeding. Childhood diet is investigated using dental pathology data in the deciduous dentitions of 78 individuals aged between 1 and 12 years. The presence of calculus, caries, and tooth wear in young children suggests that individuals were provided complementary foods and other items that impacted their dental health at an early age. The isotopic and dental data are generally consistent with the historical evidence from the Roman period with respect to the general timetable of weaning and the character of complementary foods. This is the first study to integrate isotopic and deciduous dental pathology data to explore infant and young child feeding practices in the Roman world.     

Annual variability in dentin δ15N and δ13C reveal sex differences in weaning age and feeding habits in Risso's dolphins (Grampus griseus)

Teeth of odontocetes accumulate annual dentinal growth layer groups (GLGs) that record isotope ratios, which reflect the time of their synthesis. Collectively, they provide lifetime records of individual feeding patterns from which life history traits can be inferred. We subsampled the prenatal dentin and postnatal GLGs in Risso's dolphins (Grampus griseus) (n = 65) that stranded or were collected as bycatch in Taiwan (1994–2014) and analyzed them for δ¹⁵N and δ¹³C. Age‐specific δ¹⁵N and δ¹³C values were corrected for effects of calendar year, stranding site, C/N, and sex. δ¹⁵N values were higher in prenatal layers (14.94‰ ± 0.74‰) than in adult female GLGs (12.58‰ ± 0.20‰), suggesting fetal enrichment during gestation. Decreasing δ¹⁵N values in early GLGs suggested changes in dietary protein sources during transition to complete weaning. Weaning age was earlier in males (1.09 yr) than in females (1.81 yr). Significant differences in δ¹⁵N values between weaned males and females suggest potential sexual segregation in feeding habits. δ¹³C values increased from the prenatal to the 4th GLG by ~1.0‰, indicative of a diet shift from ¹³C‐depleted milk to prey items. Our results provide novel insights into the sex‐specific ontogenetic changes in feeding patterns and some life history traits of Risso's dolphins.     

Stable isotope ratio analysis of breastfeeding and weaning practices of children from medieval Fishergate House York,UK

Rib collagen of 51 juveniles and 11 adult females from the late medieval Fishergate House cemetery site (York, UK) were analyzed using nitrogen and carbon stable isotope ratio analysis to determine the weaning age for this population and to reconstruct diet. The juveniles' ages ranged from fetal to 5–6 years, while the females were of reproductive age. Previous researchers suggested that the children from Fishergate House might have been weaned later than the medieval British norm of 2 years, based on a mortality peak at 4–6 years of age. The results show weaning was complete by 2 years of age, agreeing with previous British weaning studies. The adult female δ¹⁵N values have a mean of 11.4‰ ± 1.1‰ and the δ¹³C values have a mean of ?19.4‰ ± 0.4‰. These findings are consistent with previous isotopic studies of female diet in York during this period, though slightly lower. The weaned juvenile nitrogen values were found to be higher than the adult females (12.4‰ ± 1.0‰ for δ¹⁵N and ?19.7‰ ± 0.5‰ for δ¹³C), which might indicate a dependence on higher trophic level proteins such as marine fish or pork. Marine fish is considered a high status food and children are considered low‐status individuals at this time, making this a particularly interesting finding. Weaning does not appear to coincide with peak mortality, suggesting environment factors may be playing a larger role in child mortality at Fishergate House. Am J Phys Anthropol 152:407–416, 2013. © 2013 Wiley Periodicals, Inc.     

Stable isotopes data (delta13C, delta15N) from the cave bear (Ursus spelaeus): a new approach to its palaeoenvironment and dormancy

Palaeoclimatic data that can be extracted from the isotopic signatures of delta13C and delta15N, which are found in fossil bone collagen, should be analysed according to the specific metabolism of each species. Although Ursus spelaeus is an extinct species, its metabolism is assimilated to current, closely related species of bear. In this study, bone collagen isotopic signatures (delta13C and delta15N) of cave bears from Late Pleistocene Alpine sites were compared to those that have already been documented. The delta13C signature did not seem to follow a systematic trend according to climatic conditions, probably as a consequence of the high variability present in the values of C3 plants, which were the basis of feeding. On the contrary, the delta15N signature displayed higher values in sites corresponding to colder periods in which the delta15N signature appeared to be dominated by the physiology of dormancy. Then, due to the reuse of urea in synthesizing amino acids, the delta15N signature systematically increased along with dormancy duration. This was related to the length of winter and, in turn, depended on climate.     

Using stable isotope analysis to examine the effect of economic change on breastfeeding practices in Spitalfields, London, UK

Breastfeeding patterns were subject to a number of fads in 18th and 19th century Britain. Feeding infants by hand, rather than maternal breastfeeding or wet-nursing, became more prevalent among both the wealthy and poor. Substitute foods may have been a convenient alternative for mothers employed away from the household. This study used stable isotope ratio analysis to examine the weaning schedule in the 18th and 19th century skeletal assemblage from Spitalfields, London, UK. Analysis of 72 juvenile ribs revealed δ(15) N elevations of 2-3‰ above the adult mean for individuals up to the age of two, while elevations of 1-2‰ were observed in δ(13) C for the first year of life. This suggests that the introduction of solid foods took place before the end of the first year, and that breastfeeding had entirely ceased by 2 years of age. The age at death of many of these infants is known from historical records, and can be used to pinpoint the amount of time required for the breast milk signal to be observed in the stable isotope ratios of rib collagen. Results show that a δ(15) N elevation can be detected in the ribs of individuals who died as young as 5-6 weeks. Not all individuals at Spitalfields were breastfed, and there may not have been a single uniformly practiced weaning scheme. There is, however, more evidence for prolonged breastfeeding during the 19th century than the 18th century.     

Weaning at Anglo‐Saxon raunds: Implications for changing breastfeeding practice in britain over two millennia

This study investigated stable‐isotope ratio evidence of weaning for the late Anglo‐Saxon population of Raunds Furnells, Northamptonshire, UK. δ¹⁵N and δ¹³C values in rib collagen were obtained for individuals of different ages to assess the weaning age of infants within the population. A peak in δ¹⁵N values at about 2‐year‐old, followed by a decline in δ¹⁵N values until age three, indicates a change in diet at that age. This change in nitrogen isotope ratios corresponds with the mortality profile from the site, as well as with archaeological and documentary evidence on attitudes towards juveniles in the Anglo‐Saxon period. The pattern of δ¹³C values was less clear. Comparison of the predicted age of weaning to published data from sites dating from the Iron Age to the 19th century in Britain reveals a pattern of changing weaning practices over time, with increasingly earlier commencement and shorter periods of complementary feeding in more recent periods. Such a change has implications for the interpretation of socioeconomic changes during this period of British history, since earlier weaning is associated with decreased birth spacing, and could thus have contributed to population growth. Am J Phys Anthropol 151:604–612, 2013. © 2013 Wiley Periodicals, Inc.     

Stable nitrogen isotope analysis of dentine serial sections elucidate sex differences in weaning patterns of wild chimpanzees (Pan troglodytes)

Offspring provisioning is one of the most energetically demanding aspects of reproduction for female mammals. Variation in lactation length and weaning strategies between chimpanzees (Pan troglodytes), our closest living relative, and modern human societies have been reported. When and why these changes occurred is frequently debated. Our study used stable nitrogen isotope data of tooth root dentine from wild Western chimpanzees (Pan troglodytes verus) in Taï National Park, Côte d'Ivoire, to quantify weaning in these chimpanzees and explore if infant sex plays a role in maternal investment. We analyzed serial sections of deciduous lateral incisor root dentine from four Taï chimpanzees to establish the δ¹⁵N signal of nursing infants; we then analyzed serial sections of first permanent mandibular molar root dentine from 12 Taï chimpanzees to provide quantitative δ¹⁵N data on weaning in this population. Up to 2 years of age both sexes exhibited dentine δ¹⁵N values ≈2–3‰ higher than adult female Taï chimpanzees, consistent with a nursing signal. Thereafter a steady decrease in δ¹⁵N values consistent with the onset, and progression, of weaning, was visible. Sex differences were also evident, where male δ¹⁵N values decreased at a significantly slower rate compared to females. Confirmation of sex differences in maternal investment among Taï chimpanzees, demonstrates the viability of using isotope analysis to investigate weaning in non‐human primates. Additionally, assuming that behaviors observed in the Taï chimpanzees are illustrative of the ancestral pattern, our results provide a platform to enable the trajectory of weaning in human evolution to be further explored. Am J Phys Anthropol 153:635–642, 2014. © 2013 Wiley Periodicals, Inc.     

Isotopic fractionation with morphological change and sexual specificity in the lappet moth Euthrix potatoria

The δ¹⁵N values of adult holometabolous insects exceed those of larvae, but otherwise little information on terrestrial invertebrates has been obtained in food‐web analyses using stable isotope ratios (δ¹⁵N, δ¹³C). Changes in δ¹³C during metamorphosis and differences between males and females have not been examined. We collected the larvae and cocoons of Euthrix potatoria (L.) (Lepidoptera: Lasiocampidae) in the field and used them to assess the species’ isotopic fractionation. Each emerged moth was divided into five body parts. We conducted stable N and C isotope analyses for each body part, as well as for cocoons and exuviae, and also compared stable isotope ratios between sexes. We confirmed δ¹⁵N enrichment through metamorphosis and estimated that δ¹⁵N enrichment is accomplished by the relative concentration of ¹⁵N due to the excretion of copious meconium, which contains abundant ¹⁴N. We also observed changes in δ¹³C values through metamorphosis. Both isotope values tended to change more in males than in females. The proportion of the whole‐adult weight represented by meconium was higher in males than in females, suggesting that high meconium secretion in males contributes to the sexual difference in δ¹⁵N. These phenomena may be common in Holometabola, which require a pupal stage. For more accurate food‐web assessments, it is important to consider stable isotope changes during different life cycles, as well as sexual differences.     

Infant and child diet in Neolithic hunter-fisher-gatherers from Cis-Baikal, Siberia: intra-long bone stable nitrogen and carbon isotope ratios

Analysis of stable nitrogen and carbon isotopes (δ(15) N and δ(13) C) from subadults and adults allows for assessment of age-related dietary changes, including breastfeeding and weaning, and adoption of an adult diet. In one of the first studies of hunter-fisher-gatherer subadults from Eurasia, three Neolithic (8,800-5,200 calBP) mortuary sites from southwestern Siberia are analyzed to evaluate hypothesized differences in weaning age between Early versus Late Neolithic groups. An intra-individual sampling methodology is used to compare bone formed at different ages. Collagen samples (n = 143) from three different growth areas of long bones-the proximal metaphysis, diaphysis, and distal metaphysis-were obtained from 49 subadults aged birth to 10 years. In infants (birth to 3 years, n = 23) contrasting the δ(15) N values of the metaphysis, which contains newer bone, to the δ(15) N values of the diaphysis, which contains older bone, permits a more precise determination of breastfeeding-weaning status. In Early and Late Neolithic groups breast milk was the major protein source until the age of 2-3 years. However, there are differences in the age of weaning completion and duration: Early Neolithic groups weaned their infants at a later age and over a shorter amount of time. Differences may have affected infant morbidity and mortality, and female fecundity and inter-birth intervals. Stable isotope values in older subadults (4-10 years, n = 26) do not differ from adults suggesting the absence of age-based food allocation.     

Stable isotopes, ecological integration and environmental change: wolves record atmospheric carbon isotope trend better than tree rings

Large-scale patterns of isotope ratios are detectable in the tissues of organisms, but the variability in these patterns often obscures detection of environmental trends. We show that plants and animals at lower trophic levels are relatively poor indicators of the temporal trend in atmospheric carbon isotope ratios (delta13C) when compared with animals at higher trophic levels. First, we tested how differences in atmospheric delta13C values were transferred across three trophic levels. Second, we compared contemporary delta13C trends (1961-2004) in atmospheric CO2 to delta13C patterns in a tree species (jack pine, Pinus banksiana), large herbivore (moose, Alces alces) and large carnivore (grey wolf, Canis lupus) from North America. Third, we compared palaeontological (approx. 30000 to 12000 14C years before present) atmospheric CO2 trends to delta13C patterns in a tree species (Pinus flexilis, Juniperus sp.), a megaherbivore (bison, Bison antiquus) and a large carnivore (dire wolf, Canis dirus) from the La Brea tar pits (southern California, USA) and Great Basin (western USA). Contrary to previous expectations, we found that the environmental isotope pattern is better represented with increasing trophic level. Our results indicate that museum specimens of large carnivores would best reflect large-scale spatial and temporal patterns of carbon isotopes in the palaeontological record because top predators can act as ecological integrators of environmental change.     

Stable nitrogen and carbon isotope ratios in bone collagen as indices of prehistoric dietary dependence on marine and terrestrial resources in southern California

The ratios of 15N to 14N and 13C to 12C tend to be higher in marine than in terrestrial organisms. The concentrations of these isotopes in human bone collagen consequently can be used to make inferences about the contribution of marine and terrestrial resources to prehistoric diets. The utility of studying 15N/14N and 13C/12C ratios in conjunction with each other is illustrated by our analysis of 40 human burials from archaeological sites in the Santa Barbara Channel area of southern California. The mean delta 13C and delta 15N values (in per mil) of collagen from these skeletons decrease progressively from the Channel Islands (delta 13C = -14.0, delta 15N = +16.3) to the mainland coast (delta 13C = -14.5, delta 15N = +14.9) to the interior (delta 13C = -17.2, delta 15N = +10.9). These data suggest that Indians living on the Channel Islands during the late prehistoric period were heavily dependent on marine resources. The inhabitants of the mainland interior, in contrast, had a diet composed largely of terrestrial foods. From their isotope ratios, it appears that the Indians who lived on the mainland coast consumed a mixed diet containing substantial quantities of both marine and terrestrial resources. Differences in 15N/14N and 13C/12C ratios of individuals from mainland sites dating from the early and late prehistoric periods show that the marine component of the diet increased substantially through time. These isotopic data are consistent with pathological, faunal, and artifactual evidence of increased marine resource exploitation during the late prehistoric period.     

Early life histories of the London poor using δ13C and δ15N stable isotope incremental dentine sampling

High resolution incremental isotopic analysis of the dentine from early forming teeth, especially first molars (M1s), provides a means to assess the effects of poor childhood nutrition and healthcare on individuals in an assemblage where there are no infants to study. This approach is applied to an 18th and 19th century cemetery population associated with St Saviour's Almshouse burial ground in Southwark, London, to assess whether, or how, early dietary history, including weaning age, influenced health and nutritional status. The results show a general pattern in which non‐breast milk foods were introduced before or by 6 months of age, as indicated by elevated δ¹⁵N during this period. Almost all individuals for which we also have second molar (M2) records, showed lower δ¹⁵N values from a very young age (>1 year) until approximately 8–10 years, compared to adult values. The overall results show a significant difference in δ¹³C (p = 0 to 4sf, F = 17.327) and a weaker statistical difference in δ¹⁵N between males and females (p = 0.019, F = 5.581). One possible cause of this is a difference in the diet of males and females early in life, or alternatively, a greater susceptibility of males to nutritional deprivation compared to females. The latter argument is strengthened by a significant difference in the incidence of enamel hypoplasia between the males and females, with 7.7% of male teeth showing defects, compared to 3.9% of females. Am J Phys Anthropol 154:585–593, 2014. © 2014 Wiley Periodicals, Inc.     

Intra-tooth stable isotope analysis of dentine: A step toward addressing selective mortality in the reconstruction of life history in the archaeological record

Intra-tooth stable isotope analysis of dentine provides a more sensitive means to examine infant and childhood life history in the past than conventional cross-sectional analyses that rely on age-at-death. In addition, reconstructions of early diet and life history using an intra-tooth approach circumvent potential problems associated with mortality bias, which may operate strongly during infancy and childhood. We present new intra-tooth stable carbon and nitrogen isotope profiles in dentine collagen of early forming permanent teeth in a sample of adults from the Medieval Nubian site of Kulubnarti. We interpret the profiles in terms of weaning behavior and dietary history, and we compare profiles generated from first molars and canines to explore the degree to which these tooth types correspond. We then compare the profiles to the occurrence of linear enamel hypoplasia to assess the relationship between the timing of the weaning process and stress events. Finally, we compare the longitudinal profiles to cross-sectional stable isotope data obtained from rib collagen to investigate how life histories might differ between those that survived into adulthood and those that did not. Results suggest that canine and first molar profiles are in broad agreement, that hypoplastic stress events occurred during rather than before or after the weaning process in our sample, and that survivors appear to have weaned earlier than the average non-survivor. We suggest that this approach may be useful for addressing the effects of selective mortality on reconstructions of early life history and the relationship between early life history and morbidity. Am J Phys Anthropol 155:281–293, 2014. © 2014 Wiley Periodicals, Inc.