Influence of Phylogeny on Ecological Interaction Networks

Ecological networks are networks formed by nature where the interaction between the network's constituents is a biological interaction. The study of ecological interaction networks between species raises the important question of the role of ecological interactions in the evolution and coevolution of species. In this book we deal with a class of composite networks that are formed by two tree-like networks (T) whose endpoints touch in a bipartite network. We are interested in studying how much the topology of tree-like networks determines the connections of the bipartite network. This composite network structure is useful in evolutionary biology where T networks are phylogenetic trees of plants and animals that interact in an ecological community. We study two cases of ecological networks of mutualistic interaction: frugivorous interactions and pollination interactions. We analyze how much the phylogeny of T networks correlates with the bipartite network using a Monte Carlo approach. To this end we estimate the phylogenetic distance between elements that interact with a given species to construct an index (K) that quantifies the influence of T on the bipartite network.