A likelihood ratio test for a molecular clock is implemented in PAUP. The algorithm first builds a ML tree from the sequence data. Then the ML tree is rooted by the outgroup species. Finally, the likelihood ratio test is performed on the rooted ML tree and the sequence data. The result is saved in the output file "clockTest.log". The input sequence file must be a nexus file (for example, test.nex). After submission, a unique web link will be generated for users to download the result of the analysis.