Gene trees are generated from a pre-specified species tree under the multispecies coalescent model. The species tree is ultrametric with a molecular clock. The population size parameter theta's are specified by "#" in the species tree.
An example species tree is given below in which the numbers immediately after # are population size parameters theta in the multispecies coalescent model. There is no need to specify theta for terminal branches unless multiple alleles are sampled from each species.
An example species tree file test.sptree is available for download. After submission, a unique web link will be generated for users to download the result of the analysis.