Title
Phylogeny numbers for graphs with two triangles
Abstract
Motivated by problems of phylogenetic tree reconstruction, Roberts and Sheng introduced notions of phylogeny graph and phylogeny number. These notions are analogous to and can be considered as natural generalizations of notions of competition graph and competition number that arise from problems of ecology. Given an acyclic digraph D =( V , A ), define its phylogeny graph G = P ( D ) by taking the same vertex set as D and, for x ≠ y , letting xy ∈ E ( G ) if and only if ( x , y )∈ A or ( y , x )∈ A or ( x , a ),( y , a )∈ A for some vertex a ∈ V . Given a graph G =( V , E ), we shall call the acyclic digraph D a phylogeny digraph for G if G is an induced subgraph of P ( D ) and D has no arcs from vertices outside of G to vertices in G . The phylogeny number p ( G ) is defined to be the smallest r such that G has a phylogeny digraph D with | V ( D )|−| V ( G )|= r . In this paper, we obtain results about phylogeny number for graphs with exactly two triangles analogous to those for competition number.
Year
DOI
Venue
2000
10.1016/S0166-218X(99)00209-7
Discrete Applied Mathematics
Keywords
Field
DocType
phylogeny number,competition numbers,phylogenetic tree reconstruction,phylogeny numbers,phylogeny digraphs,phylogeny graphs,competition graphs,phylogenetic tree
Graph theory,Discrete mathematics,Combinatorics,Bound graph,Vertex (geometry),Generalization,Directed graph,Induced subgraph,Competition number,Mathematics,Digraph
Journal
Volume
Issue
ISSN
103
1-3
Discrete Applied Mathematics
Citations 
PageRank 
References 
3
0.46
1
Authors
2
Name
Order
Citations
PageRank
Fred S. Roberts152785.71
Li Sheng2204.67