DOI: 10.5061/dryad.h44j0zpvc
title: Species richness and speciation rates for all terrestrial animals emerge from a synthesis of ecological theories

description: 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
 estimate the species richness of those groups, including species yet to be
 described. We find that speciation rates per species per million years
 decrease with increasing body size. Rates are also higher for carnivores
 compared to omnivores or herbivores of the same body size. Our estimate
 for the total number of terrestrial species of animals is in the range
 1.03-2.92 million species, a value consistent with estimates from previous
 studies, despite having used a fundamentally new approach. Perhaps what is
 most remarkable about these results is that they have been obtained using
 only limited data from larger endotherms and their speciation rates, with
 the predictive process being based on mechanistic theory. This work
 illustrates the potential of a new approach to classic eco-evolutionary
 questions, while also adding weight to existing predictions. As we now
 face an era of dramatic biological change, new methods will be needed to
 mechanistically model global biodiversity at the species and individual
 organism level. This will be a huge challenge but the combination of
 general ecosystem models and neutral theory that we introduce here is a
 way to tractably achieve it.
description: # 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(12), pp.2143-2158. Combined with a range of processing steps, including calculations using ecological neutral theory. The final outputs are i) estimates of speciation rates for terrestrial endotherms, and ii) estimates of total species richness (including undescribed species) for terrestrial ectotherms. The final outputs, as well as the data from some intermediate stages are included in this dataset. Also included is a PDF which is supplementary material to the associated manuscript. ## Description of the data and file structure * *Data_dictionary* file: please use to see description of all fields that appear in all other tables. This includes units for all the fields. Mass is in grams, timescales are in millions of years (see the file for full details). * *madingley_fg_min_mass* file: please use to see minimum body mass of different functional groups in the Madingley model. This is required to interpret the ranges for each body mass bin as described in the main text of the paper. * *madingley_abundances_15simulations* file: outputs of the madingley simulations. This is an intermediate data product * *terrestrial_reptiles_distribution* file: This is an intermediate data product arising from processing input empirical data * *endotherm_speciation_rates* file: main output of our analyses giving our estimates for speciation rates of terrestrial endotherms * *endotherm_speciation_rates* file: main output of our analyses giving our estimates for total richness of terrestrial ectotherms (including undescribed species) * *Supplementary material* file: a self contained PDF file for online supplementary information. It should be interpreted in the context of the accompanying main text which is available as a preprint.