CBER External Seminar - Dr Bouwe Reijenga, University of Oxford

Abstract: Ecological communities are assembled through ecological, environmental and historical processes. Ultimately, the timing and occurrence of evolutionary historical processes, such as speciation, colonisation and niche differentiation, is fundamental to assembly. Only speciation generates diversity, colonisation is necessary to establish secondary contact between isolated species, and niche differentiation facilitates coexistence by resource partitioning. However, despite the importance of historical events, history is frequently seen as stochastic and contrasts predictability. Here, by the development of comparative phylogenetic tools and the history captured in molecular phylogenies, I investigate if history truly is unpredictable noise. Specifically, I ask (i) how speciation and colonisation shape contemporary community diversity, (ii) how colonisation is modified by niche differentiation, and (iii) the combined consequences of time available and timing of these processes for the radiation of biodiversity. Taken together, I shed new light on how historical processes and interactions between species can shape the assembly of communities and the diversity of life on Earth. While history acts in various ways over distinct scales, history is not always unpredictable. History has a much greater impact on present-day communities than appreciated, and a re-appraisal of how we view the consequences of history for communities and species diversification is necessary.