The Evolution of the Family

Benjamin E. Hardisty

A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, Department of Environmental Science, Policy and Geography, College of Arts and Sciences, University of South Florida St. Petersburg


Biological levels of complexity usually begin with the cell and extend forward to tissues, organs, organ systems, organisms, populations, community, and end with ecosystems. The family is a unit of biological complexity is missing. As a result, the evolution of altruism and cooperation from a natural selection perspective has not been produced. In the following chapters, I argue that the family is a unit of biological complexity will illuminate such mysteries as the evolution of eusociality, theories of lifetime fitness—sometimes referred to as Lifetime Reproductive Success (LRS)— cultural learning and its importance as a parallel mechanism of inheritance, finally, the resolution of evolutionary arms races. The key insight offered here is that the formation of family groups may offer an alternative to past models of group formation in organisms as diverse as snakes and humans, cultural evolution in humans and other primates and arms races in marine organisms. Each of the attempts to model the evolution of altruism and cooperation has been unsuccessful because they have ignored the fundamental reality that an extended period of parental investment combined with cooperative brood care has led to some of the most ecologically dominant organisms on earth: humans, social insects and birds.