The shape of phylogenetic trees: from taxonomic trees to the Tree of Life

Understanding the patterns and processes of diversification of life on Earth is a key challenge of science. Such diversification has given way to all living forms on the planet, extending from genes to species and from species to ecosystems. Traditionally, this assemble has printed out a huge phylogenetic tree, baptized with the name “Tree of Life”, which represents evolutionary relationships among the different taxa, and can be extended down to intra-specific levels. Here we examine the topological properties of a large set of interspecific and intraspecific phylogenetic trees and show that the branching patterns follow allometric rules conserved across the different levels in the Tree of Life [1]. With the aim of finding a possible biological interpretation for these results, we compare them to the analysis of phylogenetic trees obtained from randomly mutated sequences, taxonomic trees and protein phylogenies. These comparisons will allow us to answer the following questions: 1) Are these allometric rules biased by the reconstruction methods? 2) How do the taxonomic level constraints affect the topological properties of the interspecific phylogenies? And finally, 3) Do the protein phylogenies follow the same topological properties as the species phylogenies? [1] E. A. Herrada, C. J. Tessone, K. Klemm, V. M. Eguíluz, E. Hernández-García, and C. M. Duarte. Universal Scaling in the Branching of the Tree of Life. PLoS ONE 2008, 3(7): e2757.

Return