Listening to viral tongues: comparing viral trees using a stochastic context-free grammar.

We suggest a probabilistic method for comparing the topological features of large phylogenetic trees. Using this method, we demonstrate that a stochastic grammar can generate three influenza-subtype (A H1, A H3, and B) hemagglutinin trees used in an earlier study, with statistically similar parameters. The proposed methodology is applicable to a broad class of problems that require comparison of the topological properties of various dendrograms.