Mutualistic interactions among species play a key role in driving many population and community level processes. However, we lack a mechanistic understanding of the processes by which mutualisms shape ecological and evolutionary processes at these different levels. Hence, developing theories on the role of mutualisms in shaping ecological and evolutionary dynamics are essential. Theoretical frameworks generate empirical predictions about how mutualisms and their surrounding communities should be structured based on these mechanisms. This symposium shares findings from these theoretical frameworks with a broad audience of theoretical and empirical ecologists.Evolutionarily, there are several unanswered questions about mutualisms pertaining to their origin and subsequent feedback effects on the ecological traits of species. Our first speaker proposes a hypothesis describing the evolution of mutualisms from purely antagonistic interactions, thus providing a potential explanation for the origin of mutualisms. Our second speaker will then consider a stable plant-pollinator mutualism and combine the ecological and evolutionary dynamics of the system to explore how mutualisms will evolve to structure different community outcomes in different ecological settings.Ecologically, mutualisms can drive population dynamics of interacting species. However, these dynamics can be similar or different based on the type of mutualism considered. For instance, the currency of benefits in a nutritional mutualism (e.g. plant-rhizobia) is different from transportation mutualisms (e.g. plant-frugivore). Our third speaker will present work that differentiates between the mechanisms of these mutualisms. They will present a collection of purely ecological models that lead to differences in equilibrium population dynamics of the species. Our final speaker will then present research where they integrate mutualisms into the existing framework of Niche Theory and explore the effect of these positive interactions on species coexistence. By presenting new ways of thinking about the ecological causes and consequences of mutualisms, we hope to encourage researchers, whether they work exclusively on mutualisms or not, to apply these ideas to their own research, and to demystify theory as a valuable tool for building predictions and experiments. The symposium will conclude with a short discussion on the way forward towards a unified, empirically tractable theory of mutualisms, and discussion of some open mathematical and biological questions regarding mutualisms. Our symposium is well suited to the theme of the ESA meeting “A change is gonna come” as we advocate for a change in perspective with regards to the diverse roles of mutualisms in driving large scale ecological and evolutionary processes.