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Biological and Physical Anthropology Commons

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Full-Text Articles in Biological and Physical Anthropology

Computed Tomography Shows High Fracture Prevalence Among Physically Active Forager-Horticulturalists With High Fertility, Jonathan Stieglitz, Benjamin C. Trumble, Horus Study Team, Caleb E. Finch, Dong Li, Matthew J. Budoff, Hillard Kaplan, Michael D. Gurven Aug 2019

Computed Tomography Shows High Fracture Prevalence Among Physically Active Forager-Horticulturalists With High Fertility, Jonathan Stieglitz, Benjamin C. Trumble, Horus Study Team, Caleb E. Finch, Dong Li, Matthew J. Budoff, Hillard Kaplan, Michael D. Gurven

ESI Publications

Modern humans have more fragile skeletons than other hominins, which may result from physical inactivity. Here, we test whether reproductive effort also compromises bone strength, by measuring using computed tomography thoracic vertebral bone mineral density (BMD) and fracture prevalence among physically active Tsimane forager-horticulturalists. Earlier onset of reproduction and shorter interbirth intervals are associated with reduced BMD for women. Tsimane BMD is lower versus Americans, but only for women, contrary to simple predictions relying on inactivity to explain skeletal fragility. Minimal BMD differences exist between Tsimane and American men, suggesting that systemic factors other than fertility (e.g. diet) do not …


The Dynamics Of Men's Cooperation And Social Status In A Small-Scale Society, Christopher Von Rueden, Daniel Redhead, Rick O'Gorman, Hillard Kaplan, Michael Gurven Aug 2019

The Dynamics Of Men's Cooperation And Social Status In A Small-Scale Society, Christopher Von Rueden, Daniel Redhead, Rick O'Gorman, Hillard Kaplan, Michael Gurven

ESI Publications

We propose that networks of cooperation and allocation of social status co-emerge in human groups. We substantiate this hypothesis with one of the first longitudinal studies of cooperation in a preindustrial society, spanning 8 years. Using longitudinal social network analysis of cooperation among men, we find large effects of kinship, reciprocity and transitivity in the nomination of cooperation partners over time. Independent of these effects, we show that (i) higher-status individuals gain more cooperation partners, and (ii) individuals gain status by cooperating with individuals of higher status than themselves. We posit that human hierarchies are more egalitarian relative to other …


Kinship Ties Across The Lifespan In Human Communities, Jeremy Koster, Dieter Lukas, David Nolin, Eleanor Power, Alexandra Alvergne, Ruth Mace, Cody T. Ross, Karen Kramer, Russell Graves, Mark Caudell, Shane Macfarlan, Eric Schniter, Robert Quinlan, Siobhan Mattison, Adam Reynolds, Chun Yi-Sim, Eric Massengill Jul 2019

Kinship Ties Across The Lifespan In Human Communities, Jeremy Koster, Dieter Lukas, David Nolin, Eleanor Power, Alexandra Alvergne, Ruth Mace, Cody T. Ross, Karen Kramer, Russell Graves, Mark Caudell, Shane Macfarlan, Eric Schniter, Robert Quinlan, Siobhan Mattison, Adam Reynolds, Chun Yi-Sim, Eric Massengill

ESI Publications

A hypothesis for the evolution of long post-reproductive lifespans in the human lineage involves asymmetries in relatedness between young immigrant females and the older females in their new groups. In these circumstances, inter-generational reproductive conflicts between younger and older females are predicted to resolve in favor of the younger females, who realize fewer inclusive fitness benefits from ceding reproduction to others. This conceptual model anticipates that immigrants to a community initially have few kin ties to others in the group, gradually showing greater relatedness to group members as they have descendants who remain with them in the group. We examine …