MAXIMUM-LIKELIHOOD-ESTIMATION OF PHYLOGENY USING STRATIGRAPHIC DATA

The stratigraphic distribution of fossil species contains potential in formation about phylogeny because some phylogenetic trees are more con sistent with the distribution of fossils in the rock record than other s. A maximum likelihood estimator of phylogeny is derived using an exp licit mathematical model of fossil preservation. The method assumes th at fossil preservations within lineages follow an independent Poisson process, but. can be extended to include other preservation models. Th e performance of the method was examined using Monte Carlo simulation. The performance of the maximum likelihood estimator of topology incre ases with an increase in the preservation rate. The method is biased, like other methods of phylogeny estimation, when the rate of fossil pr eservation is low; estimated trees tend to be more asymmetrical than t he true tree. The method appears to perform well as a tree rooting cri terion even when preservation rates are low. We suggest several possib le extensions of the method to address other questions about the natur e of fossil presentation and the process of speciation and extinction over time and space.