A vigorous debate among ecologists concerns two contrasting theories of species distribution and diversity, the niche theory and the neutral theory. The 'continuum hypothesis', supported by modelling results, maintains that rather than being mutually exclusive, these theories represent two ends of a continuum. Here we develop the first empirical test capable of distinguishing between these three theories using continental-scale occurrence data from GBIF and a novel simulation framework of corresponding virtual species; application of this test to a set of 84 Australian mammals supported the continuum hypothesis over the two competing theories. Repository contains: - Manuscript supplementary information (Sp.Dis_F1000-Supplementary.pdf) - All analysis data and code (analysis_data_and_code.zip) - GBIF raw data in a DwC-A format (0054618-160910150852091.zip). Data is also publicly available via GBIF, with the following DOI: https://doi.org/10.15468/dl.3poqxs