Ultrasociality, the ability of humans to form cooperating societies consisting of huge numbers of genetically unrelated individuals, remains a largely unresolved puzzle. It is a puzzle that has warranted the attention of Dr. Peter Turchin, a professor of ecology and evolutionary biology and mathematics at the University of Connecticut, who has developed a mathematical approach to investigate the question.

"The great majority of humans today live in large-scale complex societies organized as states," Turchin explains. "Complex societies exist only on a basis of extensive cooperation among large numbers of individuals. And yet standard theories in both social science and evolutionary biology cannot explain why this happens."

Turchin applies the theory of multilevel selection to help explain human ultrasociality. Using a key mathematical result in multilevel-selection theory called the Price equation, Turchin has developed a model that describes the conditions under which human ultrasociality evolves. This mathematical result is then fleshed out with agent-based models solved on the computer. Empirical tests of the model indicate that large states should arise in regions where culturally very different people are in contact and where warfare is particularly intense.

The author of five books, Turchin has developed a field of research he calls "cliodynamics," which applies a dynamical systems approach to the study of history. Cliodynamics combines mathematical models and analyses of quantitative data to explain the processes and mechanisms that influence historical dynamics. Turchin is currently developing tests of one of his theories to American society since its independence in 1783. Using historical quantitative data on such processes as demographic growth and social stratification, the theory explains why complex human societies experience long-term oscillations in economic inequality and political instability.

Turchin will address the question of how complex human societies arise in a talk at 3:30 p.m., Nov. 16, 2010, at the National Institute for Mathematical and Biological Synthesis (NIMBioS), located on the University of Tennessee, Knoxville campus. Turchin's talk is a part of the biweekly NIMBioS Interdisciplinary Seminar Series, which is held every other Tuesday during the academic year. Seminar speakers focus on their research initiatives at the interface of mathematics and many areas of the life sciences. Each seminar begins with light refreshments starting at 3 p.m. NIMBioS is located on the 4th floor of Blount Hall,