Cladistic information content of a tree

CladisticInfo() calculates the cladistic (phylogenetic) information content of a phylogenetic object, sensu Thorley et al. (1998).

Usage

CladisticInfo(x)

PhylogeneticInfo(x)

# S3 method for class 'phylo'
CladisticInfo(x)

# S3 method for class 'Splits'
CladisticInfo(x)

# S3 method for class 'list'
CladisticInfo(x)

# S3 method for class 'multiPhylo'
CladisticInfo(x)

PhylogeneticInformation(x)

CladisticInformation(x)

Arguments

x

Tree of class phylo, or a list thereof.

Value

CladisticInfo() returns a numeric giving the cladistic information content of the input tree(s), in bits. If passed a Splits object, it returns the information content of each split in turn.

Details

The CIC is the logarithm of the number of binary trees that include the specified topology. A base two logarithm gives an information content in bits.

The CIC was originally proposed by Rohlf1982;textualTreeTools, and formalised, with an information-theoretic justification, by Thorley1998;textualTreeTools. Steel2006;textualTreeTools term the equivalent quantity "phylogenetic information content" in the context of individual characters.

The number of binary trees consistent with a cladogram provides a more satisfactory measure of the resolution of a tree than simply counting the number of edges resolved Page1992TreeTools.

References

See also

Other tree information functions: NRooted(), TreesMatchingTree()

Other tree characterization functions: Consensus(), J1Index(), Stemwardness, TotalCopheneticIndex()

Author

Martin R. Smith (martin.smith@durham.ac.uk)