John Krigbaum

Bone chemistry and bioarchaeology

Isotopic analysis of bones and teeth is now routinely used for dating skeletons and archaeological sites, and for diet, climate, and habitat reconstruction. Techniques of radiocarbon dating of bones and teeth developed by Harold Krueger and others during the 1960s laid the groundwork for subsequent research on stable carbon, nitrogen, oxygen, and strontium isotope analysis. We first review salient points in the history of research in bone isotope biogeochemistry, focusing on Krueger’s contributions. We then discuss the significance of contributions to this volume of the Journal of Anthropological Archaeology for the current state of research in dietary and environmental reconstruction in archaeology, bioarchaeology, and paleoanthropology. All papers in this volume include isotopic analysis of the carbonate phase of bone and/or tooth enamel apatite for dietary and/or environmental reconstruction. Harold Krueger was instrumental in developing methods of apatite purification for removing diagenetic phases, isotopic analysis, and interpretive models of paleodiets. Apatite isotopic analysis is now an important area of bone biogeochemistry research that provides powerful tools for reconstructing human behavior in the emerging anthropological discipline of bioarchaeology.

Evolution of the Earliest Horses Driven by Climate Change in the Paleocene-Eocene Thermal Maximum

Warming and Shrinking In most mammals, individual body sizes tend to be smaller in warmer regions and larger in cooler regions. Secord et al. (p. 959; see the Perspective by Smith) examined a high-resolution 175,000-year record of equid fossils deposited over a past climate shift—the Paleocene-Eocene Thermal Maximum—for changes in body size. Using oxygen isotopes collected from the teeth of co-occurring mammal species to track prevailing environmental temperature, a clear decrease in equid body size was seen during 130,000 years of warming, followed by a distinct increase as the climate cooled at the end of the period. These results indicate that temperature directly influenced body size in the past and may continue to have an influence as our current climate changes. Oxygen isotope measurements of fossil teeth show that the body size of the horse Sifrhippus decreased as temperature increased. Body size plays a critical role in mammalian ecology and physiology. Previous research has shown that many mammals became smaller during the Paleocene-Eocene Thermal Maximum (PETM), but the timing and magnitude of that change relative to climate change have been unclear. A high-resolution record of continental climate and equid body size change shows a directional size decrease of ~30% over the first ~130,000 years of the PETM, followed by a ~76% increase in the recovery phase of the PETM. These size changes are negatively correlated with temperature inferred from oxygen isotopes in mammal teeth and were probably driven by shifts in temperature and possibly high atmospheric CO2 concentrations. These findings could be important for understanding mammalian evolutionary responses to future global warming.

Primate Biogeography and Ecology on the Sunda Shelf Islands: A Paleontological and Zooarchaeological Perspective

Sundaland, with its complicated history of island formation and landbridge connections with mainland Southeast Asia, has figured prominently in studies of primate biogeography. The non-human primates on Sundaland are taxonomically diverse (comprising 27 species), and they exhibit relatively high levels of provinciality and endemism. By combining archaeological and paleontological evidence, with data from molecular, paleoclimatological and paleoecological studies, it is possible to reconstruct the major zoogeographic events that took place in the formation of the present-day catarrhine primate community on the Sunda Shelf islands. It can be inferred that by the Late Pliocene the main islands of the Sunda Shelf had a primate fauna that included Pongo pygmaeus (Sumatra, Java and Borneo), Hylobates spp. of the lar-group (Sumatra, Mentawai Islands, Borneo, and Java), Macaca nemestrina (Sumatra, Mentawai Islands, Borneo, and Java), the common ancestor of the Trachypithecus auratus/cristatus clade (Java and Sumatra), and Presbytis spp. (Sumatra, Mentawai Islands, Borneo, Sumatra, and Java). Most of these taxa probably arrived during the Pretiglian cold phase, starting at ~2.8 Ma, when sea levels fell by more than 100 m. It is also likely that Nasalis larvatus (Borneo) and Simias concolor (Mentawai Islands) were already present as endemic taxa in the Late Pliocene, and that their last common ancestor had arrived in the Sunda islands by the early Pliocene. Soon after this initial period of colonization, Hylobates and Presbytis underwent rapid speciation as a consequence of vicariance and relictual survivorship, giving rise to P. thomasi on Sumatra, H. klossii and P. potenziani on the Mentawai Islands, H. albibarbis, H. muelleri, P. hosei, P. frontata, and P. rubicunda on Borneo, and H. moloch and P. comata on Java. During the Late Pliocene and Early Pleistocene, probably associated with a cold climate maximum at ∼1.8 Ma, Presbytis melalophos and P. femoralis, along with Macaca fascicularis, colonized Sumatra, the Natuna Islands and Borneo from the Malay Peninsula. At about the same time, the orang-utan populations on Sumatra, Java and Borneo began to differentiate from each other. Hylobates lar, H. agilis and H. syndactylus extended their range from the Malay Pensinsula into Sumatra (and Java), probably during the Middle to Late Pleistocene, coincident with the arrival of Trachypithecus cristatus on mainland Southeast Asia. Meanwhile, Pongo pygmaeus, Hylobates syndactylus and Macaca nemestrina were extirpated on Java, probably as a consequence of a combination of ecological changes and the impact of early hominin incursions.

Neolithic subsistence patterns in northern Borneo reconstructed with stable carbon isotopes of enamel

Abstract The Neolithic period in island Southeast Asia is characterized by various population movements, technological innovations, and the introduction/adoption of agricultural foodstuffs. Human subsistence trends during this period, however, are poorly understood. Broad spectrum foraging is generally assumed for prehistoric groups utilizing rain forest food resources but the degree to which cultigens were part of the dietary repertoire remains unclear. This paper explores human subsistence patterns at three penecontemporaneous Neolithic sites in Sarawak (East Malaysia) using stable isotope ratios of carbon and oxygen derived from tooth enamel apatite. The sites (Niah Cave, Lubang Angin, and Gua Sireh) differ in local ecology and cultural circumstance but all are situated in C 3 -dominant lowland primary rain forest. Significant differences in δ 13 C values between sites likely reflect the canopy effect and variations in foraging pattern. Lower values at Lubang Angin suggest dependence upon closed forest foraging. Higher values at Neolithic Niah Cave and Gua Sireh suggest more open forest horticulture and subsistence, including some form of systematic food production, collection, and/or habitat modification.

4 – ANALYSIS OF HUMAN CREMAINS: GROSS AND CHEMICAL METHODS

Publisher Summary This chapter provides a detailed overview of the contemporary cremation process that begins with a human body and ends with a volume of inorganic matter that can fit in a small box or an urn. It discusses various methods that cremation analysts have traditionally used to analyze cremated remains. The chapter also explores the potential of using chemical methods that help to answer some basic questions about the elemental make-up and basic properties of cremated bones and teeth. The use of chemical methods for elemental analysis is now considered to be a regular step when analyzing cremains. In particular, chemical techniques can answer some basic questions about the composition of cremains that cannot be answered from gross and microscopic methods alone. Chemical methods can be used to determine whether the disputed cremains are comprised of bones or a foreign material that was substituted for the cremains. Chemical methods may provide the only supporting evidence for the identification of cremains by detecting elevated levels of normal minor elements found in bone tissue or the presence of rare trace elements that were acquired during the decedents life.

Evidence for Patterns of Selective Urban Migration in the Greater Indus Valley (2600- 1900 BC): A Lead and Strontium Isotope Mortuary Analysis

Just as modern nation-states struggle to manage the cultural and economic impacts of migration, ancient civilizations dealt with similar external pressures and set policies to regulate people’s movements. In one of the earliest urban societies, the Indus Civilization, mechanisms linking city populations to hinterland groups remain enigmatic in the absence of written documents. However, isotopic data from human tooth enamel associated with Harappa Phase (2600-1900 BC) cemetery burials at Harappa (Pakistan) and Farmana (India) provide individual biogeochemical life histories of migration. Strontium and lead isotope ratios allow us to reinterpret the Indus tradition of cemetery inhumation as part of a specific and highly regulated institution of migration. Intra-individual isotopic shifts are consistent with immigration from resource-rich hinterlands during childhood. Furthermore, mortuary populations formed over hundreds of years and composed almost entirely of first-generation immigrants suggest that inhumation was the final step in a process linking certain urban Indus communities to diverse hinterland groups. Additional multi disciplinary analyses are warranted to confirm inferred patterns of Indus mobility, but the available isotopic data suggest that efforts to classify and regulate human movement in the ancient Indus region likely helped structure socioeconomic integration across an ethnically diverse landscape.

Domination by Reptiles in a Terrestrial Food Web of the Bahamas Prior to Human Occupation

Abstract Human activities in the Bahamas and other oceanic islands have damaged terrestrial ecosystems irreparably through the extinction of indigenous species. Tortoise and crocodile bones from Abaco Island in the Bahamas sampled for 14C-dating revealed a small overlap between the last occurrence of these large reptiles and early human settlement in the Bahamas. Before their extermination approximately 1,000 years ago, the dominant herbivore and carnivore on Abaco Island were the endemic Alburys Tortoise (Chelonoidis alburyorum) and the formerly widespread Cuban Crocodile (Crocodylus rhombifer). Stable isotope data from carbon (δ13C) and nitrogen (δ15N) in bone collagen from Late Holocene fossils suggest that these large reptiles were part of a terrestrial rather than marine or estuarine food web. Our proposal that Cuban Crocodiles were once the apex terrestrial predator in the Bahamas is supported by comparisons with published δ13C values for modern marine/estuarine crocodylians as compared to those of nonmarine reptilian and mammalian carnivores. For reptiles to occupy terrestrial trophic roles distinguishes Bahamian Islands from nearby Greater Antillean Islands (Cuba, Jamaica, Hispaniola, Puerto Rico) where endemic mammals represent the largest herbivores and carnivores in prehuman times. This distinction is even greater when compared with Late Quaternary mammals of prehuman vertebrate communities in neighboring North America.

Human Paleodiet at Grand Bay, Carriacou, Lesser Antilles

ABSTRACT The island of Carriacou in the southern Grenadines, Lesser Antilles, has been the focus of interdisciplinary archaeological research since 2003, focused on ceramic-associated assemblages dating between c. AD 400 and 1300. Amerindians here exploited marine foods, but patterned subsistence has not been inferred directly from recovered human remains. Here, we present the first stable isotope data from bone collagen and bone apatite of individuals (n = 14) from the Grand Bay site that date to post–AD 1000. Average δ13Cco (−12.8‰), δ15N (11.1‰), δ13Cap (−8.6‰), and Δ13Cap-co (4.1‰) values substantiate a marine-based diet. No significant differences are observed between males and females; however, one subadult is an isotopic outlier based on its δ13Cco and Δ13Cap-co values. Bone collagen values suggest high marine protein at Carriacou, different from data reported for contemporaneous groups in the Greater Antilles, broadly similar to the northern Lesser Antilles, and most similar to the Bahamas, where reef-based systems are ubiquitous. Bone apatite and bone collagen isotope results underscore the importance of shellfish on Carriacou as previously observed in the zooarchaeological record. At present, these data do not provide the interpretative power to confirm or refute the presence/absence of maize in the diet during the mid-Ceramic Saladoid in the southern Lesser Antilles.

Effects of caloric restriction on nitrogen and carbon stable isotope ratios in adult rat bone

RATIONALE Stable isotope analysis is a valuable technique for dietary estimation in ecological and archaeological research, yet many variables can potentially affect tissue stable isotope signatures. Controlled feeding studies across a range of species have consistently demonstrated impacts of caloric restriction on tissue stable isotope ratios, but most have focused on juvenile, fasting, and/or starving individuals, and most have utilized soft tissues despite the importance of bone for paleodietary analyses. The goal of this study was to determine whether temporally defined, moderate food restriction could affect stable carbon and/or nitrogen isotope ratios in adult mammalian bone - a tissue that arguably reflects long-term dietary signals. METHODS Adult rats fed a standard laboratory diet were restricted to 45% of ad libitum intakes for 3 or 6 months. Relevant anatomical and physiological parameters were measured to confirm that the restriction protocol resulted in significant nutritional stress and to provide independent data to facilitate interpretation of stable isotope ratios. Femoral bone δ(13)Ccollagen, δ(15)Ncollagen, and δ(13)Capatite values were determined by isotope ratio mass spectrometry. RESULTS Calorie-restricted animals exhibited a small, yet significant enrichment in (15)Ncollagen compared with control animals, reflecting protein-calorie stress. While the δ(13)Ccollagen values did not differ, the δ(13)Capatite values revealed less enrichment in (13)C than in controls, reflecting catabolism of body fat. Independent anatomical and physiological data from these same individuals support these interpretations. CONCLUSIONS Results indicate that moderate caloric restriction does not appreciably undermine broad interpretations of dietary signals in adult mammalian bone. Significant variability among individuals or groups, however, is best explained by marked differences in energy intake over variable timescales. An inverse relationship between the δ(13)Capatite and δ(15)Ncollagen values observed in this study indicates that a more robust pattern is expected with more severe or prolonged restriction and suggests this pattern may have utility as a marker of food deprivation in archaeological populations.

Paleodiet in Late Preceramic Peru: Preliminary Isotopic Data From Bandurria

ABSTRACT The Preceramic occupation of Peru has historically received little attention from scholars. Recent excavations on the North-Central Coast of Peru have identified several large sites with monumental architecture dating to the Late Preceramic Period (3000–1800 BC). Monumental architecture and dense occupation at these sites indicates a degree of sedentism despite the lack of evidence for large-scale agriculture for comestibles and ceramic production. Questions remain, however, with respect to the nature of human dietary regimes without technological innovations that mirror agricultural modes of food production. This preliminary study uses stable isotope ratio analysis of human bones and teeth to assess the dietary regimes at the coastal site of Bandurria. Results support a marine-based diet for individuals sampled. These data are consistent with the maritime hypothesis which suggests that subsistence economy during the formation of Andean civilization relied on small schooling fish as the staple protein and was supplemented by C3 type carbohydrates (i.e., squashes, potatoes) (Moseley 1975, 1985, 1992; Shady Solis 2006a, 2006b). When isotopic data from Bandurria individuals are compared to data from Caral (Coutts et al. 2008), paleodietary inference suggests that marine resources were consumed in lower frequencies at sites further inland than coastal ones. These data may support a proto-horizontality model of social exchange between coastal and lowland areas during the Late Preceramic Period (Rostworowski de Diez Canseco 1975, 1977) reflected in the material markers of dietary resources, and further may suggest that coastal maritime-adapted polities were integrated into social and material exchange networks.