Temporal trends in the Colonisation of the Pacific: Palaeodemographic Insights

Abstract

The colonisation of eastern parts of the Pacific Islands was the last phase in the preindustrial expansion of the human species. Given the scale and challenges of the endeavour it is unsurprising that scholars have long been interested in understanding the conditions that drove and supported the exploration and settlement of this vast region. There has been speculation as to the influence of demographic factors, either as drivers or in some way regulating the rate and success of human expansion, but testing this has proven challenging. This study evaluates two hypotheses of population dynamics: the adaptation/resilience hypothesis, which proposes that populations respond to localised environmental conditions and changes in subsistence strategy, technology, differences in pathogen loads, and other events that occur at different times in different places; and the temporal hypothesis, which proposes that populations respond to major events such as climate change that occur in a region at an absolute point in, or over an absolute period of, time (noting that the two hypotheses are not mutually exclusive). Applying new methods for estimating the rate of natural population increase from human skeletal remains, this study utilised 23 samples to evaluate trends in population increase following the human expansion into the region. The results indicate a trend in population growth following colonisation, with initially high population growth, followed by a significant decrease and subsequently an increase in growth rates. The lack of a temporal trend may represent a high degree of heterogeneity in the impacts of climate change on individual archipelagos and islands.

Approximate Bayesian Computation of radiocarbon and paleoenvironmental record shows population resilience on Rapa Nui (Easter Island)

“…3500 individuals is most consistent with the archeological and historical evidence. At a broader scale, our results demonstrate that the logistic demographic patterns on Rapa Nui were similar to those proposed for other islands in Polynesia, e.g., 59,[90][91][92] .…”

From the Ground Up: A Multidisciplinary Approach to Past Fertility and Population Narratives

“…This model was analyzed in SPSS Amos Version 28 (2021, https://www.ibm.com/support/pages/ibm-spss-amos-28-documentation ) using data derived from McFadden et al ( 2021 ) and Nunn and Britton ( 2001 ), including estimates from the latter publication (in the absence of published raw data) and simulated data where values were missing (21 cases, estimated by regression analysis). When compared with the null hypothesis model (nothing is related) and the saturated model (everything is related), the specified model demonstrated a stronger relationship with fertility (indicated by the D 0–14 /D proxy from McFadden et al, 2021 ). Figure 4 visualizes the specified model and correlations between variables, and Table 1 reports the model comparison.…”

“…The model includes a number of environmental variables that may be expected to interact with fertility based on modern observations. The example study was localized to the Pacific Islands since good data are available for paleoclimate variables and paleodemographic fluctuations have been previously estimated (McFadden et al, 2021 ). Additionally, the use of an island model (see Terrell, 2020 and Leppard et al, 2021 for robust discussion) hypothetically assists in streamlining this demonstration exercise.…”

“…Fertility proxy data, arable land, total land, and island type were obtained from the study by McFadden et al ( 2021 ) examining population increase in the Pacific Islands. In this study, fertility was estimated based on the age-at-death distribution of burials, which may be used as a proxy for population increase (McFadden & Oxenham, 2018b ).…”

Unraveling Island Economies through Organic Residue Analysis: The Case of Mocha Island (Southern Chile)

“…Insular biogeographic conditions, distance from mainland enclaves, seafaring technology, and the flexibility of a subsistence economy were some of the interplaying factors conditioning island-colonization efforts (Crowther et al 2016;Leppard 2014;O'Connor et al 2019;Takamiya 2006). Over the preceding several decades, genetic, archaeological, and linguistic studies have increased our understanding of these processes in regions such as the west and northeast Pacific Ocean (Horsburgh and McCoy 2017;Lepofsky et al 2015;McFadden et al 2021;Potter and White 2009;Walworth 2014). Despite extensive archaeological research along the western coast of South America (Beresford-Jones et al 2018;King et al 2018;Reyes et al 2022;Stothert et al 2003), large geographic areas of the Chilean coast remain poorly understood.…”