consider a population of fixed size that evolves over time. at each time, the genealogical structure of the population can be described by a coalescent tree whose branches are traced back to the most recent common ancestor of the population. this gives rise to a tree-valued stochastic process. we will study this process in the case of populations whose genealogy is given by the bolthausen-sznitman coalescent. we will focus on the evolution of the time back to the most recent common ancestor and the total length of branches in the tree.