A k-graph is called a (k, m)-tree if it can be obtained from a single edge by consecutively adding edges so that every new edge contains k&m new vertices while its remaining m vertices are covered by an already existing edge. We prove that there are (e(k&m)+m)!(e( k m )&e+1) e&2 e!m!((k&m)!) e disti
Enumerating phylogenetic trees with multiple labels
β Scribed by L.R. Foulds; R.W. Robinson
- Publisher
- Elsevier Science
- Year
- 1988
- Tongue
- English
- Weight
- 524 KB
- Volume
- 72
- Category
- Article
- ISSN
- 0012-365X
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β¦ Synopsis
Evolutionary
trees are used in biology to illustrate postulated ancestral relationships between species and are often called phylogenetic trees. They can be characterized in graph theoretic terms by certain classes of labelled trees. Disjoint subsets of the labelling set are assigned to tree vertices so that all pendant vertices and any vertices of degree two are labelled.
Here we determine exact and asymptotic numbers for two classes of trees in which multiple vertex labels are allowed.
In the first class vertices of degree two are forbidden and in the second class vertices of degree greater than two cannot be labelled.
A general method is presented for deriving the asymptotic analysis of any multiple label case. Asymptotic results for the two classes of trees under study are then obtained by applying this method to previously published results.
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