A Counterexample to Fitch’s Method for Maximum Parsimony Trees

  • G. William Moore


A major goal in numerical taxonomy over the past decade has been to discover a rapid method for finding the ancestral tree, or dendrogram, requiring the minimum number of evolutionary steps or changes, given an initial set of contemporary Operational Taxonomic Units (OTUs) for which the character states are known. Short of searching all possible dendrograms and all possible ancestral configurations for each dendrogram, the problem has never been solved in the general case. FARRIS (1970) has suggested a variety of intriguing approaches but has not proved them mathematically. ESTABROOK (1968) has solved the problem mathematically for the special case in which the CAMIN-SOKAL (1965) hypothesis is satisfied, but this special case has rather limited applications (MOORE, GOODMAN, and BARNABAS, 1973). FITCH (1971) has focused his attention on the less spectacular but more attainable goal of finding maximum parsimony ancestral character states when both the contemporary character states and the dendrogram are known. Although his method may, in many cases, find a maximum parsimony solution, it is relatively easy to demonstrate that it will not always do so.


Maximum Parsimony Preliminary Phase Mutation Length Parsimony Solution Dendrogram Topology 
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.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Literature Cited

  1. CAMIN, J. H. and R. R. SOKAL. 1965, A method for deducing branching sequences in phylogeny. Evolution 19:311–326.CrossRefGoogle Scholar
  2. ESTABROOK, G. F. 1968. A general solution in partial orders for the Camin-Sokal model in phylogeny. J. Theor. Biol. 21:421–438.PubMedCrossRefGoogle Scholar
  3. FARRIS, J. S. 1970. Methods for computing Wagner trees. Syst. Zool. 19:83–92.CrossRefGoogle Scholar
  4. FITCH, W. M. 1971. Toward defining the course of evolution: minimum change for a specific tree topology. Syst. Zool. 20:406–416.CrossRefGoogle Scholar
  5. MOORE, G. W., J. BARNABAS and M. GOODMAN. 1973. A method for constructing maximum parsimony ancestral amino acid sequences on a given network. J. Theor. Biol. 38:459–485.PubMedCrossRefGoogle Scholar
  6. MOORE, G. W., M. GOODMAN and J. BARNABAS. 1973. An iterative approach from the standpoint of the additive hypothesis to the dendrogram problem posed by molecular data sets. J. Theor. Biol. 38:423–457.PubMedCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1974

Authors and Affiliations

  • G. William Moore
    • 1
    • 2
  1. 1.Department of AnatomyWayne State University College of MedicineDetroitUSA
  2. 2.Pathologisches Institut, Ludwig- Aschoff-HausFreiburg 1. Br.West Germany

Personalised recommendations