Climatic and Behavioural Influences on Postcranial Robusticity Among Holocene Foragers

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Abstract

Postcranial morphology is commonly used as the basis for interpreting human behavioral and environmental adaptations in the past. Recent evidence suggests that diaphyseal morphology may be subject to climatic influences; further, there may be a selective gradient in which distal elements are subject to tighter climatic and biomechanical constraints than proximal elements are. Hence, the influence of climate and behaviour may differ throughout the skeleton.

This dissertation compares the postcranial robusticity of four groups of foragers, to elucidate behavioiural and climatic (quantified using effective temperature) influences on diaphyseal morphology. Foraging groups include early historic Andaman Islanders (n=32), Later Stone Age southern Africans (n=83), archaic foragers from southern Ontario (n=15) and late prehistoric Tierra del Fuegians (n=34). Diaphyseal cross-sectional geometry is quantified for the clavicles, humeri and ulnae bilaterally, and femora and tibiae unilaterally. Body size standardized geometric properties are compared using analysis of covariance and canonical variates analysis.

Climatic influences on skeletal robusticity are strong at some skeletal sites, especially the subtrochanteric femur location. The midshaft femoral shape and robusticity of the femur are strongly correlated with terrestrial mobility, among male and female subsamples. In the upper body, diaphyseal strengths are strongly correlated with marine mobility. There is no correspondence between tipper body bilateral asymmetry and material technology, but males have higher levels of asymmetry than females in all groups. Overall, diaphyseal robusticity corresponds with patterns of terrestrial and marine mobility. The positive relationship between robusticity and habitual behaviour is strongest in the distal limb elements. Thus, there is less disparity between observed morphological variability and functional adaptation in the distal elements.

This dissertation demonstrates that it is possible to partition climatic and behavioural influences on the skeleton. It is therefore possible to interpret habitual activity of foragers from diaphyseal robusticity.

Cited Works (19)

Year	Entry
1990	Brown TD, Pedersen DR, Gray ML, Brand RA, Rubin CT. Toward an identification of mechanical parameters initiating periosteal remodeling: a combined experimental and analytic approach. J Biomech. 1990;23(9):893-905.
1992	Rubin CT, Bain SD, McLeod KJ. Suppression of the osteogenic response in the aging skeleton. Calcif Tiss Int. April 1992;50(4):306-313.
1980	Nagurka ML, Hayes WC. An interactive graphics package for calculating cross-sectional properties of complex shapes. J Biomech. 1980;13(1):59-64.
1983	Ruff CB, Hayes WC. Cross‐sectional geometry of Pecos Pueblo femora and tibiae: a biomechanical investigation, II: sex, age, and side differences. Am J Phys Anthropol. 1983;60(3):383-400.
1991	Turner CH. Homeostatic control of bone structure: an application of feedback theory. Bone. 1991;12(3):203-217.
1989	Martin RB, Burr DB. Structure, Function, and Adaptation of Compact Bone. New York, NY: Raven Press; 1989.
1990	Rubin CT, McLeod KJ, Bain SD. Functional strains and cortical bone adaptation: epigenetic assurance of skeletal integrity. J Biomech. 1990;23(suppl 1):43-54.
1994	Forwood MR, Turner CH. The response of rat tibiae to incremental bouts of mechanical loading: a quantum concept for bone formation. Bone. November–December 1994;15(6):603.
1996	Haapasalo H, Sievanen H, Kannus P, Heinonen A, Oja P, Vuori I. Dimensions and estimated mechanical characteristics of the humerus after long-term tennis loading. J Bone Miner Res. June 1996;11(6):864-872.
1998	Martin RB, Burr DB, Sharkey NA. Skeletal Tissue Mechanics. New York, NY: Springer-Verlag; 1998.
1983	Ruff CB, Hayes WC. Cross‐sectional geometry of Pecos Pueblo femora and tibiae: a biomechanical investigation, I: method and general patterns of variation. Am J Phys Anthropol. 1983;60(3):359-381.
1984	Currey JD. Mechanical Adaptations of Bone. Princeton, NJ: Princeton University Press; 1984.
1995	Rubin CT, Gross TS, McLeod KJ, Bain SD. Morphologie stages in lamellar bone formation stimulated by a potent mechanical stimulus. J Bone Miner Res. March 1995;10(3):488-495.
1981	Ruff CB. Structural Changes in the Lower Limb Bones With Aging At Pecos Pueblo [PhD thesis]. Philadelphia, PA: University of Pennsylvania; 1981.
2000	Ruff CB. Body size, body shape, and long bone strength in modern humans. J Hum Evol. February 2000;38(2):269-290.
1984	Rubin CT, Lanyon LE. Dynamic strain similarity in vertebrates: an alternative to allometric limb bone scaling. J Theo Biol. March 21, 1984;107(2):321-327.
1997	Frost HM. On our age‐related bone loss: insights from a new paradigm. J Bone Miner Res. October 1997;12(10):1539-1546.
1994	Bouxsein ML, Myburgh KH, van der Meulen MCH, Lindenberger E, Marcus R. Age-related differences in cross-sectional geometry of the forearm bones in healthy women. Calcif Tiss Int. February 1994;54(2):113-118.
1993	Martin B. Aging and strength of bone as a structural material. Calcif Tiss Int. February 1993;53(suppl 1):S34-S40.

Cited By (1)

Year	Entry
2007	Auerbach BM. Human Skeletal Variation in the New World During the Holocene: Effects of Climate and Subsistence Across Geography and Time [PhD thesis]. Johns Hopkins University; August 2007.