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Complete tree phylogenetic beta-diversity measure

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The unweighted complete tree (CT) measure calculates the dissimilarity between a pair of communities by considering the amount of shared, unique, and external branch length within a tree spanning all sequences from all communities. It is an unweighted or qualitative measure as only the presence or absence of a sequence is considered. This calculator can be used with the phylo.betadiversity command. The dissimilarity between communities i and j is given by:

<math>D_{CT} = \frac{b+c}{a^*+b+c+d}</math>

where,

<math>a^*</math> = the amount of branch length shared by the two communities within the CL subtree.

<math>b</math> = the amount of branch length unique to community i.

<math>c</math> = the amount of branch length unique to community j.

<math>d</math> = the amount of branch length external to communities i and j.

Mathematical properties

Points-of-interest

Further information

Parks, DH and Beiko, RG. (2011). Quantifying phylogenetic β-diversity over rooted and unrooted trees. (in preparation)