The expected length of pendant and interior edges of a Yule tree

摘要: The Yule (pure-birth) model is the simplest null of speciation; each lineage gives rise to a new independently with same rate λ. We investigate expected length an edge chosen at random from resulting evolutionary tree. In particular, we compare randomly selected pendant edge. provide some exact formulae, and show how our results depend slightly on whether depth tree or number leaves conditioned on, λ known estimated using maximum likelihood.