This paper explores the use of complex adaptive systems theory in development policy analysis using a case study drawn from recent events in Uganda. It documents the changes that took place in the farming system in Soroti district during an outbreak of African cassava mosaic virus disease (ACMVD) and the subsequent decline in cassava production - the main staple food in the area. Resultant adaptation impacts are analysed across cropping, biological, economic and social systems each of which operate as an interlinked sub-system. The policy implications of this story suggest a policy agenda that recognises adaptation capacity as the life blood of complex adaptive systems. Since these types of systems are found in all realms of human activity, it follows that strengthening this capacity is a key developmental priority that requires linking together new configurations of actors and resources to tackle an ever-changing set of contexts.