Reconstructing prehistoric demography: What role for extant hunter‐gatherers?

Abstract

Demography is central to biological, behavioral, and cultural evolution. Knowledge of the demography of prehistoric populations of both Homo sapiens and earlier members of the genus Homo is, therefore, key to the study of human evolution. Unfortunately, demographic processes (fertility, mortality, migration) leave little mark on the archeological and paleoanthropological records. One common solution to this issue is the application of demographic data from extant hunter‐gatherers to prehistory. With the aim of strengthening this line of enquiry, here we outline some pitfalls and their interpretative implications. In doing so, we provide recommendations about the application of hunter‐gatherer data to the study of demographic trends throughout human evolution. We use published demographic data from extant hunter‐gatherers to show that it is the diversity seen among extant hunter‐gatherers—both intra‐ and inter‐population variability—that is most relevant and useful for understanding past hunter‐gatherer demography.

Hunter-gatherer genomes reveal diverse demographic trajectories during the rise of farming in Eastern Africa

“…10,16,[31][32][33][34][35][36] This list of responses is not exhaustive, nor are they mutually exclusive; the history of any particular group may have involved multiple different responses at various times. 37 Importantly, genetic data can give insights into the extent to which population size change and gene flow were associated with these different responses.…”

What is the expected human childhood? Insights from evolutionary anthropology

“…Human societies are better characterized as diverse (Barrett, 2021;Singh & Glowacki, 2021), and throughout history, many societies were highly cooperative, egalitarian, and practiced extensive alloparenting, with children learning valuable skills and knowledge in mixed-age peer groups (Kelly, 2013;Meehan & Crittenden, 2016;Lew-Levy et al, 2017). Our goal is therefore to synthesize a nuanced portrait of childhood throughout human history, particularly one that can accommodate variation across cultures and ecologies (Barnard, 2004;Humphreys & Salo, 2020;Page & French, 2020).…”

“…Note that life expectancy at age 15 will be lower than the mode, because the distribution around the mode is not symmetrical; there are more deaths to the left of the mode than to the right (Walker et al, 2006). Though estimates of prehistoric humans are more uncertain, the predicted longevity of H. habilis is 52-56 years and that of H. erectus 60-63 years (Charnov & Berrigan, 1993;Hammer & Foley, 1996; see also Page & French, 2020). Thus, the difference in life expectancy between past and present societies seems to be mainly driven by mortality in early life.…”

“…Second, we have used data from contemporary hunter-gatherer societies to inform estimates of historical populations, because for roughly 95% of our species' evolutionary history, children were likely born into a hunter-gatherer society. However, such inferences should be qualified by the fact that there are important differences between historical and contemporary hunter-gatherer societies (Kelly, 2013;Page & French, 2020). First, some contemporary hunter-gatherer societies have experienced devastating consequences from coming into contact with Western populations, such as catastrophic disease and resource deprivation (Diamond, 2013;Hill & Hurtado, 1996).…”

A modeling approach to estimate the historical population size of the Patagonian Kawésqar people

“…Like in other historical hunter-gatherer societies (e.g. Page and French, 2020; Tallavaara and Jørgensen, 2021), population size estimations for the Kawésqar tradition have been problematic. Chilean official census only includes valid estimations of the historical Kawésqar population since 2002 (MINSAL, 2009; Valdés, 2017), although Martinic (1989) cited an estimation in 1895.…”