Traditionally, genetic history of species has been modeled using phylogenetic trees. Recently, scientists have begun using phyolgenetic networks to model more complex occurrences, such as hybridization, which cannot be displayed by trees. Phylogenetic networks are represented by network graphs which are trivalent, directed graphs without directed circuits. In this paper we discuss the mathematics of network graphs. Given an unoriented trivalent graph, we determine a necessary and sufficient condition for orienting the graph as a network graph.
Ruth Charney, Department of Mathematics, Brandeis University firstname.lastname@example.org
"Orientability of Phylogenetic Network Graphs,"
Rose-Hulman Undergraduate Mathematics Journal: Vol. 8
, Article 3.
Available at: http://scholar.rose-hulman.edu/rhumj/vol8/iss2/3