Two different types, networks that provide an explicit picture with hybridization etc, or an abstract network. - Roland Krause

An early approach using a mathematical generalization were split networks, which provide an abstraction but no explanation. - Roland Krause

See dendroscope.org - Roland Krause

Go to an explicit networks where you have hybridization and speciation events, e.g. in plant evolution, horizontal gene transfer in bacteria. Both appear similar in this framework. - Roland Krause

When modelling reticulate evolution a node can have a variable input from different parents, e.g. 50/50 for plants, 95/5 for horizontal gene transfer settings. - Roland Krause