At all scales, biology presents an astounding diversity of length and time scales. On the sub-cellular scale, molecular competition and positive feedback acting on short time scales maintain cells in specialized states, setting the foundation for complexity of multicellular organisms. On larger scales, competition in turn selects for ecosystems where different species coexist over long time. This general pattern calls for research with a focus on diversity, with competition as its “engine". The meeting should facilitate new initiatives in exploring the origin and sustainability of diversity.