Fig. 1

Flowchart to show the steps carried out for the basic model, which simulates the evolution of a community of individuals of different species undergoing neutral ecological drift. The number of individuals in each species at time t is represented by the vector n _t , where the element n _i , t is the number of individuals of species i at time t, and i = 1 , … , S _t . \( {\boldsymbol{n}}_t^d \) is the vector of individuals that are removed from each of the species in the model at time t (boxes 1 and 2). The vector containing the number of individuals in each species at intermediate timepoints is indicated by n ^∗, and the number of species in the population at intermediate timepoints is S ^∗ _t . \( {{\boldsymbol{n}}^{\ast}}_t^b \) (box 3) is the vector of individuals in each species chosen to reproduce at time t. ν is the probability of speciation occurring per birth event (box 5). Total population size at time t (boxes 1 and 3) is given by \( {J}_{M,t}=\sum_{i=1}^{S_t}{n}_{i,t} \). Function mult(x, y) (boxes 1 and 3) generates a multinomially distributed random number vector of size x, where y is a vector giving the probability of drawing the individuals from each class. Function rnd.(0,1) (box 5) generates a random variable distributed evenly between 0 and 1. The dashed rectangle indicates steps conducted while looping through each birth k in each species i