Inferring Ancestral Character States

  • Gary A. Churchill
Part of the Evolutionary Biology book series (EBIO, volume 32)


We wish to address the question of how much information is available in a set of observable individuals to help us reconstruct the ancestral state of a character. The question can be framed in variety of contexts, but we focus on the following scenario. An investigator is studying a group of organisms that are related by a phylogenetic tree with a known topology and known branch lengths (presumably based on a sufficient amount of prior data). A new character is observed, and the investigator wishes to infer the state of the character at one or more of the internal nodes of the tree. This scenario was motivated by a study of fungus-growing ants for which a molecular phylogeny of the ant species is available (Fig. 1) and the character of interest is the type of fungus grown (T. Schultz, personal communication).


Posterior Probability Posterior Distribution Prior Distribution Character State Branch Length 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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  1. Bernardo, J. M., Smith, A. F. M., 1997, Bayesian Theory, Wiley, New York.Google Scholar
  2. Felsenstein, J., 1981, Evolutionary trees from DNA sequences: A maximum likelihood approach, J. Mol. Evol. 17:368–376.PubMedCrossRefGoogle Scholar
  3. Lehmann, E. L., 1983, Theory of Point Estimation, Wiley, New York.Google Scholar
  4. Schultz, T. R., Cocroft, R. B., and Churchill, G. A., 1996, The reconstruction of ancestral character states, Evolution 50:504–511.CrossRefGoogle Scholar
  5. Taylor, H. M., and Karlin, S., 1986, An Introduction to Stochastic Modelling, Academic Press, London.Google Scholar

Copyright information

© Springer Science+Business Media New York 2000

Authors and Affiliations

  • Gary A. Churchill
    • 1
  1. 1.The Jackson LaboratoryBar HarborUSA

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