Species richness and speciation rates for all terrestrial animals emerge from a synthesis of ecological theories

The total number of species on earth and the rate at which new species are created are fundamental questions for ecology, evolution and conservation. These questions have typically been approached separately, despite their obvious interconnection. In this study we approach both questions in conjunction, for all terrestrial animals. To do this, we combine two previously unconnected bodies of theory: general ecosystem models and individual based ecological neutral theory. General ecosystem models provide us with estimated numbers of individual organisms, separated by functional group and body size. Neutral theory, applied within a guild of functionally similar individuals, connects species richness, speciation rate and number of individual organisms. In combination, for terrestrial endotherms where species numbers are known, they provide us with estimates for speciation rates as a function of body size and diet class. Extrapolating the same rates to guilds of ectotherms enables us to esti..., , , # Species richness and speciation rates for all terrestrial animals emerge from a synthesis of ecological theories [https://doi.org/10.5061/dryad.h44j0zpvc](https://doi.org/10.5061/dryad.h44j0zpvc) The data was produced by first conducting simulation runs of the Madingley Model using default parameters Harfoot, M.B., Newbold, T., Tittensor, D.P., Emmott, S., Hutton, J., Lyutsarev, V., Smith, M.J., Scharlemann, J.P. and Purves, D.W., 2014. Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model. PLoS biology, 12(4), p.e1001841. We also used empirical data from Wilman, H., Belmaker, J., Simpson, J., de la Rosa, C., Rivadeneira, M.M. and Jetz, W., 2014. EltonTraits 1.0: Species‐level foraging attributes of the world's birds and mammals: Ecological Archives E095‐178. Ecology, 95(7), pp.2027-2027. and Etard, A., Morrill, S. and Newbold, T., 2020. Global gaps in trait data for terrestrial vertebrates. Global Ecology and Biogeography, 29(...,