Abstract
The interrelatedness of biological, ecological, and social systems has been recognised since ancient times. Conservation biologists, ecologists, and other scientists and non-scientists have consistently worked across disciplines to solve practical challenges related to health. However, many public and animal health activities happen within sectoral compartments. One Health, a multisectoral approach to complex health challenges, emerged internationally in response to emerging global zoonotic disease threats, particularly influenza A(H5N1), and has improved collaboration between the public health and animal health sectors. However, due to the context in which it emerged and evolved, limitations to One Health persist. These include the scope of actors, experiences, information, and perspectives included; the methodologies and methods applied; and the worldviews considered. Indigenous and local communities are consistently excluded, as are other disciplines, such as the social sciences and humanities. The environment and ecology sectors were not authentically included in international One Health discourse until formation of the Quadripartite in 2022. Such limitations were reflected in research initiated to support policy at the international and national levels. In such research, the restricted scope of actors and application of mainstream scientific methodologies limited the impact of the outcomes. The current global context of exceedingly complex and imminent crises and an increased policy focus on social-ecological system sustainability now require One Health to evolve in scope, methodology, and worldview. Two practical ways forward are therefore proposed: (1) establishing methodologies for braiding together information from myriad sources, including non-mainstream sources of knowledge, and (2) applying Systems Thinking methodologies within One Health. In this way, One Health can evolve to capture diverse knowledges and to consider the nuance of complex socio-ecological contexts. Only by evolving can One Health effectively and sustainably address contemporary global challenges, now and into the future.