Dynamics and evolution of biological and social networks

From genes to species: Universal scaling?

Author: E. Alejandro Herrada, IFISC (CSIC-UIB).

Names and affiliation of other authors:
Claudio Juan Tessone (ETH Zurich), Konstantin Klemm (University of Leipzig), Víctor M. Eguíluz (IFISC), Emilio Hernández-García (IFISC), Carlos M. Duarte (IMEDEA)

Oral presentation

Many biological processes, from cellular metabolism to population dynamics, are characterized by allometric scaling (power-law) relationships between size and rate. During the last years different research groups have developed statistical analysis tools, based on allometric scaling concepts, for the study of tree-like transportation networks (for example to characterize how branching properties change with network size). Among the biological processes naturally described in terms of a tree-like topology, the expansion of both the protein families phylogenies and the species phylogenies happening during the evolution of the organisms are conveniently represented as phylogenetic trees. Here we compare the allometric scaling approaches for the statistical analysis of both protein families phylogenies and species phylogenies.
Considering the phylogenies as a group of tips and nodes linked by branches, a node ultimately represents a diversification event. For each node i, a subtree Si is made up of a root at node i and all the descendant nodes bellow i. That point of view allows us to understand how much the (sub)tree members diversify from i, through the subtree size Ai, and how is this diversity arranged, through several topological measures characterizing the shape of the subtree Si. Universal scaling relationships between shape and size of protein and species phylogenies are revealed and discussed.

Formatted version of the abstract or additional information

Dynamics and evolution of biological and social networks. February 18-20th, 2008. Mallorca, Spain.