Adapting in the Arctic: Habitual activity and landscape interaction in Late Holocene hunter‐gatherers from Alaska

Abstract

Objectives This study compares lower limb diaphyseal robusticity between Native Alaskan hunter‐gatherers to reconstruct patterns of mobility and engagement with terrain. Materials and methods Ancestral remains included in this study date between 600 and 1800 C.E. and were divided into three regions: Coastal Bay, Far North Coastal, and Inland/Riverine. Cross‐sectional properties were determined at femoral and tibial midshafts and standardized by powers of body mass and bone length. Results Consistently elaevated areas and second moments of area were found in ancestral remains from the Far North Coastal, while the Coastal Bay remains had reduced diaphyseal robusticity. Individuals from the Inland/Riverine region were intermediate in robusticity for male femora, but similar to the Coastal Bay group for females. Sexual dimorphism was greatest in the Inland/Riverine ancestral remains and comparable between Coastal Bay and Far North Coastal regions. Conclusions Ancestral remains from the Far North Coastal region have the greatest diaphyseal robusticity in response to intensive hunting and travel over rugged terrain. Reduced sexual dimorphism in the Far North Coastal region suggest female participation in hunting activities. Intermediate diaphyseal robusticity among Inland/Riverine males and increased sexual dimorphism reflects diverse patterns of mobility in relation to the hunting cycle between males and females. Reduced diaphyseal robusticity and sexual dimorphism among the Coastal Bay group is associated with sedentary villages established around net fishing in regions with low relief. Such findings argue against technocentric views of sedentism in hunter‐gatherer lifeways and generally reflect diverse adaptive strategies and interaction with local terrain among Indigenous Late Holocene hunter‐gatherers of Alaska.

Body size and shape in insular environments and applications of the island rule in biological anthropology

“…Humeri and lower limb robusticity values are most similar to, and even surpass, values in groups with intense activity in oceanic marine and terrestrial mountainous environments. These results support previous research that found high levels of femoral and tibial robusticity in non-industrialized individuals who inhabit rugged environments (Stock and Pfieffer, 2004;Temple et al, 2021;Ruff, 1999;Marchi, 2008), and high levels of humeral robusticity in marine-hunter-gatherers who heavily rely on diverse oceanic resources (Stock and Pfeiffer, 2001;Stock, 2006;Temple et al, 2021;Weiss, 2003). Further, these results indicate that despite marine-hunter-gatherers having a localized food resource, similar to sedentary agricultural groups, high levels of mobility are required in desert ecologies potentially from the need to travel between freshwater springs and subsistence resources.…”

“…To make inferences on the types and intensity of activity of individuals from the Cape Region and Central Desert Sierras, cross-sectional geometric properties of the humerus, femur, and tibia were compared to a diverse sample of non-industrial humans who differed in behaviors (marine-hunter-gatherers to agriculturalists) and terrain (Table 1). Alaska North Coast, Alaska Coast, and Andaman Island samples represent individuals with high levels of maritime adaptations with varying degrees of marine hunting, watercraft use, swimming, and shellfish gathering (Table 1; Stock and Pfeiffer, 2001;Stock, 2006;Temple et al, 2021). Alaska Coast and Andaman Island are of individuals with low levels of terrestrial mobility in relatively flatter terrain, while Alaska North…”

“…Coast is characterized by individuals with high levels of activity in both rugged oceanic and mountainous terrestrial terrain. Alaska River samples represent semi-sedentary hunter-gatherers in a rugged terrain, while Pecos Pueblo are of sedentary agriculturalists with logistical hunting and foraging in rugged terrain (Table 1; Ruff and Hayes, 1983a,b;Temple et al, 2021).…”

“…Analyses of cross-sectional geometry has successfully detected population differences related to terrain type, including differences between terrestrial and water transport. Increases in cross-sectional areas and second moments of area are associated with increased loading intensity in active and mobile individuals, but also in groups who inhabit areas with rugged terrain (Ruff, 1987;Weiss, 2003;Wescott, 2006;Marchi, 2008;Ruff, 2019;Temple et al, 2021). Individuals who navigate rugged oceanic or mountainous terrain have humeral, femoral, and tibial midshaft cross-sections with elevated bone mass and torsional rigidity compared to groups who traverse flat aquatic or terrestrial terrain (Weiss, 2003;Bridges, 2005;Marchi, 2008).…”

What is normal bone health? A bioarchaeological perspective on meaningful measures and interpretations of bone strength, loss, and aging

“…While these evolutionary studies clearly demonstrate a general decrease or changes in skeletal robusticity over time correlated with subsistence mobility or technological innovation, without sufficient sample sizes and wider range of age distributions, they are not able to detect or make meaningful interpretations of age‐ or sex‐related bone loss. However, recent comparative studies of cortical long bone robusticity in a variety of modern populations have found varying patterns of sexual dimorphism that have been suggested to reflect differences in gendered activities and behavior (Laffranchi et al, 2020; Saers et al, 2017; Temple et al, 2021; Zelazny et al, 2021). While these studies do not consider age‐related changes and/or do not have sufficient sample sizes to do so, they do underscore the plasticity of bone morphology with behavior/lifestyle and do not support the “mismatch” hypothesis that females in modern human populations are predestined to have less robust bones or bone fragility.…”