The model of evolution we are familiar with is perhaps a perfect tree.

Things replicate themselves till the mutations happen by chance and therefore the model is almost always a tree. But then the way human interaction works is a lot different.

And this model is basically a complicated network of influences.

Networks reconfigure themselves and over time each node will probably influence others. What happens is interesting as mathematically it can be seen as a giant set of influences existing. Each new creation is either a subset of the set or a subset ⋃ {new idea} which is then synced back to the set.