This presentation will describe how speciation times can be computed and estimated under the Jukes-Cantor model on a four-taxon species tree. These computations are specific to trees that satisfy the molecular clock and show that species tree branch lengths are identifiable in this setting. However, it is unclear if the molecular clock can be relaxed or if other complicated models could be used to draw similar conclusions. This presentation will also provide the necessary background on the coalescent process and the process of mutation for general Markov models.