Universality in food webs

Among recently studied real-world networks, food webs are particularly interesting since they provide an example of biological organization at the largest scale, namely that of ecological communities. Quite surprisingly, recent results reveal that food webs do not display those properties which are observed in almost all other networks, such as a scale-free degree distribution and a large clustering coefficient. However, when food webs are regarded from the point of view of trasportation networks, it is possible to uncover very interesting scaling properties which are displayed by other trasportation systems, namely vascular and river networks. While other topological properties appear to vary across different webs depending on specific aspects, such scaling relations are universal. An interpretation of these results in terms of the interplay of universal and nonuniversal mechanisms in food web evolution is suggested.