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.

(((S1:0.1,S2:0.1):0.1#0.05,(S3:0.1,S4:0.1):0.1#0.05):0.01#0.05,S5:0.03)#0.05;

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.