During the first decade and a half of the development of the systems ecology paradigm (SEP) most research efforts were placed on learning about how the biophysical realms of ecosystems function and how simulation models could aid gaining that understanding. Missing from that research were the obvious connections of humans as components of ecosystems, not simply as controllers. In 1981 the US National Science Foundation (NSF) Programs Ecosystems Studies and Anthropology funded the South Turkana Ecosystem Project. It was the first time that an ecosystem study had included the human component as a full actor in an ecosystem. The NSF has since created the Dynamics of Coupled Natural and Human Systems program, the sole purpose of which is to fund these types of projects. The human side of SEP has grown in other directions as well including, agro-ecosystem ecology, understanding ecosystem services and effects of land fragmentation, Citizen Science, and providing guidance to the management of natural and human-dominated systems and the improvement of human welfare. Ongoing research has led to the realization that the human residents of the ecosystems under study can engage with research scientists to co-create knowledge about the operation of their own systems.