En este estudio paleodemográfico contribuimos a la discusión sobre el impacto de la incorporación de recursos vegetales domesticados en poblaciones del sitio Jaime Prats-1, el área de entierros humanos con mayor número de individuos del centro occidente argentino. La ubicación espacial y temporal del sitio arqueológico se corresponde con el registro de cultígenos prehispánicos en la región, por lo que resulta relevante para entender la dinámica poblacional en un área de interacción entre grupos cazadores-recolectores y sociedades agricultoras. Los resultados del análisis de los perfiles de edades de muerte, el Índice de Juventud y la suma de probabilidades de los fechados radiocarbónicos disponibles, indican un pulso de crecimiento demográfico entre los 2000 y los 1500 años aP, correspondiente al período de uso del sitio. Tomando como referencia un conjunto de cazadores-recolectores contemporáneos y otro de agricultores tardíos, ambos procedentes de la región, Jaime Prats-1 ocupa una posición intermedia, de confluencia entre ambos sistemas de subsistencia.

Skousen and Aiuvalasit critique our article on the post-Mississippian occupation of the Horseshoe Lake watershed (White et al. 2020) along two lines: (1) that our findings are not supported due to a lack of archaeological evidence, and (2) that we do not consider alternative hypotheses in explaining the lake's fecal stanol record. We first respond to the matter of fecal stanol deposition in Horseshoe Lake and then address the larger issue, the primacy of archaeological data in interpreting the past.

Population density is an important variable in the development of social complexity. Estimating population densities from the archaeological record requires combining estimates of population, area, and time. Archaeological population estimates tend to be reported as a maximum population derived from the total accumulation of discrete archaeological material types, usually ceramics or radiocarbon (14C) dates. However, given the palimpsest nature of the archaeological record at recurrently occupied archaeological sites, these maximal, total estimates are, at best, a poor reflection of contemporaneous populations. I present a method for calculating average yearly population densities for occupations at a large, multicomponent site using a combination of distributional data and 60 14C dates. By employing this method at other sites in the same region, modeling intra-regional population dynamics at fine time scales will be possible.

Paleodemographic simulations are rare in the Maya region, because generally the skeletal collections do not represent well the ancient living population, are poorly preserved, and lead to flawed age-at-death estimations. The skeletal collection of Xcambó, however, is suitable for paleodemographic analysis and is large enough to enable comparison of paleodemographic trends between the Early (AD 250–550) and Late Classic (AD 550–750) periods. Three demographic simulations were generated; two relied on growth rates calculated from the site's previous archaeodemographic data, and a third simulation was based on a stationary scenario by applying Weiss's (1973) and Séguy and Buchet's (2013) models. All simulations indicate that Xcambó’s Late Classic population was growing faster than its Early Classic peers, with higher rates of survivorship and more severe mortality rates. We argue that the differences are more likely due to shifts in lifestyle and wealth than to environmental changes, as is confirmed by other bioarchaeological and skeletal indicators.

Synchronized demographic and behavioral patterns among distinct populations is a well-known, natural phenomenon. Intriguingly, similar patterns of synchrony occur among prehistoric human populations. However, the drivers of synchronous human ecodynamics are not well understood. Addressing this issue, we review the role of environmental variability in causing human demographic and adaptive responses. As a case study, we explore human ecodynamics of coastal hunter-gatherers in Holocene northern Europe, comparing population, economic, and environmental dynamics in two separate areas (northern Norway and western Finland). Population trends are reconstructed using temporal frequency distributions of radiocarbon-dated and shoreline-dated archaeological sites. These are correlated to regional environmental proxies and proxies for maritime resource use. The results demonstrate remarkably synchronous patterns across population trajectories, marine resource exploitation, settlement pattern, and technological responses. Crucially, the population dynamics strongly correspond to significant environmental changes. We evaluate competing hypotheses and suggest that the synchrony stems from similar responses to shared environmental variability. We take this to be a prehistoric human example of the “Moran effect,” positing similar responses of geographically distinct populations to shared environmental drivers. The results imply that intensified economies and social interaction networks have limited impact on long-term hunter-gatherer population trajectories beyond what is already proscribed by environmental drivers.

The occupation history of the Cahokia archaeological complex (ca. AD 1050–1400) has received significant academic attention for decades, but the subsequent repopulation of the region by indigenous peoples is poorly understood. This study presents demographic trends from a fecal stanol population reconstruction of Horseshoe Lake, Illinois, along with information from archaeological, historical, and environmental sources to provide an interpretation of post-Mississippian population change in the Cahokia region. Fecal stanol data indicate that the Cahokia region reached a population minimum by approximately AD 1400, regional population had rebounded by AD 1500, a population maximum was reached by AD 1650, and population declined again by AD 1700. The indigenous repopulation of the area coincides with environmental changes conducive to maize-based agriculture and bison-hunting subsistence practices of the Illinois Confederation. The subsequent regional depopulation corresponds to a complicated period of warfare, epidemic disease, Christianization, population movement, and environmental change in the eighteenth century. The recognition of a post-Mississippian indigenous population helps shape a narrative of Native American persistence over Native American disappearance.

With generous support from the National Science Foundation, we have spent the past four years developing an archaeological radiocarbon database for the United States. Here, we highlight the importance of spatial data for open-access, national-scale archaeological databases and the development of paleodemography research. We propose a new method for analyzing radiocarbon time series in the context of paleoclimate models. This method forces us to confront one of the central challenges to realizing the full potential of national-scale databases: the quality of the spatial data accompanying radiocarbon dates. We seek to open a national discussion on the use of spatial data in open-source archaeological databases.

Temporal frequency distributions of radiocarbon ages from archaeological sites can be used as a proxy record for human paleodemography after correction for taphonomic bias, or the time dependent loss of sediments due to erosion. Surovell et al. (2009) presented a global taphonomic correction model based on radiocarbon ages from volcanic deposits that has since been used by several researchers for paleodemographic reconstructions. This method is based on the assumption that the best indicator of relative human population density over time is not the absolute abundance of archaeological materials over time but, instead, the abundance of cultural material relative to geologic contexts in which those materials can occur. To verify the Surovell et al. model, in this paper we take 2457 radiocarbon ages from geologic contexts collected from published literature to create an independent model of taphonomic bias. We find that between 1 and 39 ka, the two curves are largely indistinguishable, but that they diverge in recent times. This suggests that current global models of taphonomic correction can be used to reconstruct human populations for the late Quaternary, but that demographic reconstructions remain challenging for the most recent two millennia.