The Conditioned Reconstructed Process

J Theor Biol. 2008 Aug 21;253(4):769-78. doi: 10.1016/j.jtbi.2008.04.005. Epub 2008 Apr 15.


We investigate a neutral model for speciation and extinction, the constant rate birth-death process. The process is conditioned to have n extant species today, we look at the tree distribution of the reconstructed trees--i.e. the trees without the extinct species. Whereas the tree shape distribution is well-known and actually the same as under the pure birth process, no analytic results for the speciation times were known. We provide the distribution for the speciation times and calculate the expectations analytically. This characterizes the reconstructed trees completely. We will show how the results can be used to date phylogenies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Animals
  • Computer Simulation*
  • Genetic Speciation*
  • Genetic Variation
  • Models, Genetic*
  • Phylogeny*