This paper presents new benefit–cost estimates for the Tulsa universal pre-K program. These calculations are based on estimated effects, from two recent papers, of Tulsa pre-K on high-school graduation rates and college attendance rates of students who were in kindergarten in the fall of 2006. In the current paper, educational effects from these prior papers are used to infer lifetime earnings effects. Our conservative estimates suggest that per pre-K participant, the present value of earnings effects in 2021 dollars is $25,533, compared with program costs of $9,628, for a benefit–cost ratio of 2.65. Compared to prior benefit–cost studies of Tulsa pre-K, this benefit–cost ratio is below what was predicted from Tulsa pre-K’s effects on kindergarten test scores, but above what was predicted from Tulsa pre-K’s effects on grade retention by ninth grade. This fading and recovery of predicted pre-K effects as children go through K-12 and then enter adulthood is consistent with prior research. It suggests that pre-K may have important effects on “soft skills,” such as persisting in school, and reminds us that short-term studies of pre-K provide useful information for public policy.

Campeche, one of the Spanish Empire's main Mexican ports, was a place where previously distinct cultures and populations intermingled during the colonial era (AD 1540–1680). Investigation of the town's central plaza revealed a Hispanic cemetery of multi-ethnic burials. The authors combine previous analyses with newly generated genome-wide data from 10 individuals to trace detailed life histories of the mostly young, local Indigenous Americans and first-generation European and African immigrants, none of whom show evidence of genetic admixture. These results provide insights into the individual lives and social divides of the town's founder communities and demonstrate how ancient DNA analyses can contribute to understanding early colonial encounters.

Continuing isotopic investigation of the sacrificial burials and trophies beneath the Feathered Serpent Pyramid (Temple of Quetzalcoatl) in ancient Teotihuacan, Mexico, has produced new results. Isotopic proveniencing using bioapatite strontium and structural carbonate oxygen isotopes in tooth enamel was applied to 39 samples, 24 from the sacrificial victims and 15 from the trophy jaws. Both the strontium and oxygen isotope ratios suggest that most or all of the sacrificial victims came from the central highlands of Mexico, which includes the area of Teotihuacan. In this sense, we find somewhat less multiethnicity represented among the military at Teotihuacan than previously thought. Analysis of carbon isotope ratios in enamel structural carbonate indicated a childhood diet dominated by maize, relatively homogeneous among the victims at the pyramid, and typical for much of pre-Hispanic Mesoamerica.

Isotopic investigations of human burials from excavations of the Autonomous University of Campeche (CIHS) at the prehispanic Maya capital of Calakmul in southeastern Mexico, near the border with Guatemala, include determination of radiocarbon dates; carbon and nitrogen isotope ratios in collagen; and strontium, carbon, and oxygen isotope ratios in tooth enamel. A total of 22 human and 5 faunal samples analyzed for strontium isotopes reveal a narrow range of variation in values, pointing to the likely local origin of over two-thirds of the central population of Calakmul, including two of its rulers. Carbon and nitrogen data confirm a typical Classic Maya diet at the site and identify a diet high in meat consumption for one dynastic individual. Interpreted jointly, the isotopic information offers new perspectives on the provenience and lifestyles of the residents of Calakmul, including a potential place of origin for the royal occupant of chamber tomb Burial VII-1.

Recent genetic, isotopic and linguistic research has dramatically changed our understanding of how the Corded Ware Culture in Europe was formed. Here the authors explain it in terms of local adaptations and interactions between migrant Yamnaya people from the Pontic-Caspian steppe and indigenous North European Neolithic cultures. The original herding economy of the Yamnaya migrants gradually gave way to new practices of crop cultivation, which led to the adoption of new words for those crops. The result of this hybridisation process was the formation of a new material culture, the Corded Ware Culture, and of a new dialect, Proto-Germanic. Despite a degree of hostility between expanding Corded Ware groups and indigenous Neolithic groups, stable isotope data suggest that exogamy provided a mechanism facilitating their integration. This article should be read in conjunction with that by Heyd (2017, in this issue).

The mass grave found near Talheim in southern Germany dates to approximately 7000 years ago and contains the skeletal remains of 34 individuals from the Early Neolithic period, associated with what is known as the Linearbandkeramik culture. These individuals appear to have been the victims of a massacre, based on the presence of numerous lethal head wounds, several arrow wounds, and the placement of all of these individuals in the same burial pit. The burials are considered to likely represent members of the same community attacked and executed by another group. In this study we examine the remains from the mass grave at Talheim for information on migration and community structure using strontium isotope ratios in tooth enamel. In essence, strontium isotope ratios are signatures of different rock types. The food chain moves these atoms into the human skeleton from bedrock through water, soils, plants, and herbivores. Because human tooth enamel does not change after formation, it provides a stored signal of the strontium isotopes of the place of birth. If the strontium isotope ratio of the place of death is different, the individual under study must have moved from one geology to another during his or her lifetime. Isotopic provenancing shows that several of the individuals in the group at Talheim were born in a different geological location. We discuss the results of the analysis and its significance in terms of questions of migration and community structure in the Early Neolithic of prehistoric Europe.

Human skeletal remains from Bell Beaker graves in southern Germany, Austria, the Czech Republic, and Hungary were analyzed for information on human migration. Strontium isotope ratios were measured in bone and tooth enamel to determine if these individuals had changed ‘geological’ residence during their lifetimes. Strontium isotopes vary among different types of rock. They enter the body through diet and are deposited in the skeleton. Tooth enamel forms during early childhood and does not change. Bone changes continually through life. Difference in the strontium isotope ratio between bone and enamel in the same individual indicates change in residence. Results from the analysis of 81 Bell Beaker individuals indicated that 51 had moved during their lifetime. Information on the geology of south-central Europe, the application of strontium isotope analysis, and the relevant Bell Beaker sites is provided along with discussion of the results of the study.

The study of the Bom Santo Cave (central Portugal), a Neolithic cemetery, indicates a complex social, palaeoeconomic, and population scenario. With isotope, aDNA, and provenance analyses of raw materials coupled with stylistic variability of material culture items and palaeogeographical data, light is shed on the territory and social organization of a population dated to 3800–3400 cal BC, i.e. the Middle Neolithic. Results indicate an itinerant farming, segmentary society, where exogamic practices were the norm. Its lifeway may be that of the earliest megalithic builders of the region, but further research is needed to correctly evaluate the degree of this community's participation in such a phenomenon.

Ship burials are a well-known feature of Scandinavian Viking Age archaeology, but the discovery of 41 individuals buried in two ships in Estonia belongs to the Pre-Viking period and is the first of its kind in Europe. The two crews met a violent end around AD 750, and were buried with a variety of richly decorated weapons, tools, gaming pieces and animal bones. The rich grave goods suggest that this was a diplomatic delegation protected by a cohort of elite warriors. They were armed with swords of Scandinavian design, possibly from the Stockholm-Mälaren region, and stable isotope analysis is consistent with that being the probable homeland of the crew.

Human sacrifice in ancient Mesoamerica was strongly linked with ritual behaviour and mythical beliefs. Yet it is rarely possible to explain the mythical associations of archaeological deposits derived from human sacrifice. In this article, we integrate archaeological, taphonomic and isotopic analysis to reconstruct the ritual behaviour that resulted in the formation of a partially cremated primary burial at the Lowland Maya city of Tikal. Taphonomic reconstruction reveals details about the form of death and combustion of two males, while isotopic studies hint at their probable geographic origin. To explain this ritual, we assess the relevance of widespread Mesoamerican mythical beliefs about the origin of the sun and the moon, and discuss the theoretical and methodological issues involved in this comparison. The burial's association with an E-Group compound makes it significant for the interpretation of these specialized architectural arrangements in southern Mesoamerica. It also pertains to a critical period in Tikal's history, marked by intensified cultural and political interaction with the highland Mexican city of Teotihuacan, manifest in this burial by the presence of imported green obsidian spear points. We propose that this unique context resulted from a sacrificial reenactment of the mythological birth of the sun and the moon.

Anchored in archaeological, bioarchaeological, and chemical research conducted at the coastal enclave of Xcambo, this paper examines Classic period Maya coastal saline economic production and exchange, along with the lifestyle, ethnicity, and mobility of the traders. Nestled in the coastal marshlands of the northern Yucatan, Mexico, Xcambo functioned as a salt production center and port during its occupation, maintaining long-reaching ties with other parts of the Maya world and Veracruz. Considered together, the different data sets document a reorientation in Xcambo's exchange routes and connections, which are echoed by increasingly diverse cultural affiliations and an increasing geographic mobility of Xcambo's merchants. This new information confirms the known pattern of gradually intensifying, though still relatively independent, trade dynamics along the Maya coast in the centuries leading up to the so-called “Maya collapse” and the rise of a new merchant league under the control of Chichen Itza. It was this new order that probably led to the swift end of Xcambo soon after a.d. 700.

The Illerup Aadal weapon sacrifice mirrors the material world of a Germanic army from c. AD 210. Apart from the personal equipment and the weaponry of more than 400 warriors, it comprises four horses. The present paper gives the first conclusive analysis of the skeletal remains of these animals, involving osteological investigation and strontium isotope analysis. The results shed new light on the character of the sacrificial ceremonies which unfolded in the aftermath of Iron Age battles; on the nature of cavalry and its significance in Iron Age warfare; and on the much debated question as to where the army of Illerup Aadal had originally come from.

The circular fortress of Trelleborg on Zealand in Denmark is well known as a military camp with a key role in the formation of the Danish state under Harald Bluetooth in the tenth century AD. Taking a sample of 48 burials from the fort, strontium isotope analysis once again demonstrates its ability to eavesdrop on a community: at Trelleborg, the young men in its cemetery were largely recruited from outside Denmark, perhaps from Norway or the Slavic regions. Even persons buried together proved to have different origins, and the three females sampled were all from overseas, including a wealthy woman with a silver casket. Trelleborg, home of Harald Bluetooth's army, was a fortress of foreigners with vivid implications for the nature of his political mission.

We analyzed strontium isotopes in more than 500 samples of shell, bone, and dental enamel from modern and archaeological contexts throughout Mesoamerica. The results correspond closely with expectations based upon the local geology and earlier measurements of geological materials. The results show that isotopic variation is significant across Mesoamerica. Thus strontium isotope ratios in dental enamel, which mark the place of childhood residence, can be used not only to document mobility but also in some cases to determine geographic origin. We present five archaeological case studies to illustrate the anthropological significance and range of applications for this technique: the origins of individuals in the “Oaxaca Barrio” at Teotihuacan, a northern origin for the founder of Copan, a local king at Tikal, the regional origin of two of Palenque's rulers, and individuals of African birth in a colonial cemetery in Campeche.

A group of Linearbandkeramik people at Talheim, Germany were previously found to have died at the same time, probably in a massacre, and the authors were able to ask some searching questions of their skeletons. The isotope signatures of strontium, oxygen and carbon, which gave information on diet and childhood region, showed up three groups which correlated with hereditary traits (derived previously from the analysis of the teeth). In the local group, there were many local children but no adult women, suggesting they had been selectively taken alive at the time of the massacre. Another group, with isotope signatures derived from upland areas, includes two men who may have been closely related. A third group has a composition suggestive of a nuclear family. The variations of one type of isotope signature with another suggested subtle interpretations, such as transhumance, and a probable labour division in the community between stockholders and cultivators. Here we see the ever-growing potential of these new methods for writing the ‘biographies’ of prehistoric skeletons.

The archaeological site of Aztalan in southeastern Wisconsin is a large, palisaded complex of mounds and other structures along the banks of the Crawfish River in Jefferson County. The unusual nature of this settlement has been noted for many years and the origin of the inhabitants has been the subject of considerable debate. The similarities between the materials at Aztalan and other Mississippian period sites to the south in Illinois have long been noted. The largest center of the Mississippian culture at Cahokia near East St. Louis, Illinois, has often been cited as the likely home of the founders of Aztalan. Using strontium isotopes in human teeth and bone we examine the question of migration and the possibility of nonlocal individuals among the skeletal remains from Aztalan. Our results suggest that there were a number of foreign individuals among the locals. The isotopic signal for some of the foreigners matches values from Cahokia, but does not prove that this was their place of origin.

To investigate geographic origins of the sacrificial Burials 2–5 from the Moon Pyramid at Teotihuacan and to reconstruct changes in residence since their childhoods, we analyzed tooth enamel for oxygen- and strontium-isotope ratios and bone just for oxygen-isotope ratios. The combination of these analytical techniques involves both climatic and geological variables, therefore enhancing resolution of geographic identification. Most of the sacrificed individuals appear to have been born in a foreign location. These regions probably include other areas within the Basin of Mexico and the central highlands, as well as the Gulf Coast and the Sierra Madre del Sur. Other possible regions of origin are the southern highlands, the Motagua Valley, and the Maya Lowlands. There is considerable overlap in the oxygen-isotope ratios between the Moon Pyramid and Feathered Serpent Pyramid victims, but each structure contains a group of isotopically distinct individuals. The Moon Pyramid sacrifices include some individuals with high oxygen-isotope ratios, possibly indicating the Gulf Coast or Maya Lowlands, whereas the Feathered Serpent Pyramid contains a distinct group with very low oxygen-isotope ratios, possibly indicating Oaxaca, Michoacan, or the coastal plain and piedmont of Guatemala. The sacrifices in the two pyramids also differ in their patterns of movement. Most of the Moon Pyramid victims appear to have arrived in the city recently, but the majority of those from the Feathered Serpent Pyramid had lived in Teotihuacan for a long time before their death.

The 2005 articles by Stoltman et al. and Flannery et al. to which Neff et al. (this issue) have responded are not an indictment of instrumental neutron activation analysis (INAA) but, rather, of the way Blomster et al. (2005) misuse it and of the hyperbolic culture-historical claims they have made from their INAA results. It has long been acknowledged that INAA leads not to sources but to chemical composition groups. Based on composition groups derived from an extremely unsystematic collection of sherds from only seven localities, Blomster et al. claim that the Olmec received no carved gray or kaolin white pottery from other regions; they also claim that neighboring valleys in the Mexican highlands did not exchange such pottery with each other. Not only can one not leap directly from the elements in potsherds to such sweeping culture-historical conclusions, it is also the case that other lines of evidence (including petrographic analysis) have for 40+ years produced empirical evidence to the contrary. In the end, it was their commitment to an unfalsifiable model of Olmec superiority that led Blomster et al. to bypass the logic of archaeological inference.