My research focuses on trying to understand the evolution of human bio-cultural variation. I conduct fieldwork in lowland South America with indigenous horticulturalists. This research is comprised of 4 main areas of interest:
Cultural phylogenetics: investigation of population expansions, phylogeographies, and cultural evolution using phylogenetic methods based on language
Partible paternity: evolutionary history of the conception belief that multiple men can be co-genitors of one child; partible paternity beliefs are common in lowland South American yet essentially unheard of in the rest of the world
Hunter-gatherer cultural variation: construction and analysis of comparative databases involving kin co-residence, marriage patterns, and various cultural traits
Life-history variation: quantifying age-specific rates of growth, fertility, and mortality across natural-fertility human populations to compare with other primates
Opportunities for Students
Opportunities abound for students to explore any of the above areas of research. Interested students with questions concerning research opportunities and/or graduate studies are encouraged to contact me via email.
Publications
2011
Hogg, R. T, R. S. Walker. Life-history correlates of enamel microstructure in Cebidae (Platyrrhini, Primates). Anatomical Record294:2193-2206 [pdf]
Gawlik, A, R. S. Walker, Z. Hochberg. Impact of infancy duration on adult size in 22 subsistence-based societies. Acta Paediatrica100:e248-e252 [pdf]
Hochberg, Z, A. Gawlik, R. S. Walker. Evolutionary fitness as a function of pubertal age in 22 subsistence-based traditional societies. International Journal of Pediatric Endocrinology2011:2. [pdf]
Walker, R. S., K. R. Hill, M. V. Flinn, R. M. Ellsworth. Evolutionary history of hunter-gatherer marriage practices. PLoS ONE 6(4): e19066. [pdf]
Hill, K., R. S. Walker, M. Bozicevic, J. Eder, T. Headland, B. Hewlett, A. M. Hurtado, F. Marlowe, P. Wiessner, and B. Wood. Co-residence patterns in hunter-gatherer societies show unique human social structure. Science 331:1286-1289. [pdf]
Walker, R. S. and L. A. Ribeiro. Bayesian phylogeography of the Arawak expansion in lowland South America. Proceedings of the Royal Society B 278:2562-2567 [pdf]
Walker, R. S. and M. Hamilton. Social complexity and linguistic diversity in Austronesian and Bantu population expansions. Proceedings of the Royal Society B278:1399-1404 [pdf]
2010
Walker, R. S., M. V. Flinn, and K. R. Hill. Evolutionary history of partible paternity in lowland South America. Proceedings of the National Academy of Sciences, USA107:19195-19200 [pdf]
Burger, O., R. S. Walker, and M. J. Hamilton. Lifetime reproductive effort in humans. Proceedings of the Royal Society B277:773-777 [pdf]
2009
Hamilton, M. J., O. Burger, J. P. DeLong, R. S. Walker, M. Moses, and J. H. Brown. Population stability, cooperation and the invasibility of the human species. Proceedings of the National Academy of Sciences, USA106:12255-12260 [pdf]
2008
Walker, R. S., M. Gurven, O. Burger, and M. J. Hamilton. The trade-off between number and size of offspring in humans and other primates. Proceedings of the Royal Society B275:827-833 [pdf]
Walker, R. S. and M. J. Hamilton. Life history consequences of density dependence and the evolution of human body sizes. Current Anthropology49:115-122 [pdf]
2007
Hamilton, M. J., B. T. Milne, R. S. Walker, O. Burger, and J. H. Brown. The complex structure of hunter-gatherer social networks. Proceedings of the Royal Society B274:2195-2202 [pdf]
Hamilton, M. J., B. T. Milne, R. S. Walker, and J. H. Brown. Nonlinear scaling of space use in human hunter-gatherers. Proceedings of the National Academy of Sciences, USA104:4765-4769 [pdf]
Hill, K., A. M. Hurtado, and R. S. Walker. High adult mortality among Hiwi hunter-gatherers: Implications for human evolution. Journal of Human Evolution52:443-454 [pdf]
2006
Walker, R. S., O. Burger, J. Wagner, and C. Von Rueden. Evolution of brain size and juvenile periods in primates. Journal of Human Evolution51:480-89 [pdf]
Walker, R. S., M. Gurven, K. Hill, A. Migliano, N. Chagnon, R. De Souza, G. Djurovic, R. Hames, A. M. Hurtado, H. Kaplan, K. Kramer, W. J. Oliver, C. Valeggia, and T. Yamauchi. Growth rates and life histories in twenty-two small-scale societies. American Journal of Human Biology18:295-311 [pdf]
Walker, R. S., K. Hill, O. Burger, and A. M. Hurtado. Life in the slow lane revisited: Ontogenetic separation between chimpanzees and humans. American Journal of Physical Anthropology129:577-583 [pdf]
Gurven, M. and R. S. Walker. Energetic demand of multiple dependents and the evolution of slow human growth. Proceedings of the Royal Society B273: 835-841 [pdf]
2005
Burger, O., M. Hamilton, and R. S. Walker. The prey as patch model: A marginal gains curve for vertebrate prey. Journal of Archaeological Science32:1147-1158 [pdf]
2003
Walker, R. S. and K. Hill. Modeling growth and senescence in physical performance among the Ache of Eastern Paraguay. American Journal of Human Biology15:196-208 [pdf]
2002
Walker, R. S., K. Hill, H. Kaplan, and G. MacMillan. Age-dependency in hunting ability among the Ache of eastern Paraguay. Journal of Human Evolution42:639-657 [pdf]
2001
Todd, L. C., D. C. Jones, R. S. Walker, P. Burnett, and J. Eighmy. Late archaic bison hunters in Northern Colorado: 1997-1999 Excavations at the Kaplan-Hoover Bison Bonebed (5LR3953). Plains Anthropologist46:125-147 [pdf]
