Starting point of the joint research project was a hypothesis emphasising the importance of the duplication of proteins in the course of evolution. If the gene encoding a protein is duplicated in the genome, which often happens in evolution, original and copy will interact with the same partners in the protein network. Once original and copy diverge over time, novel proteins with individual features and own partners in the network will emerge. Interactions in the network would thereby not be newly created but evolve through duplication and divergence from simpler ancestors.
Protein networks of extinct ancestors were reconstructed
The two workgroups around bioinformatician Thomas Rattei and physicist Hernan Makse tested and improved this hypothesis in an elaborate computational experiment. They developed a novel method for the reconstruction of protein networks of extinct evolutionary ancestors from the genomes and networks of present-day species. Data of seven species from various domains of life were used: from bacteria, fungi, plants, animals to humans.
Present-day networks complex structures through simple mechanisms
The comparison of these reconstructed ancient protein networks yielded a surprisingly clear result: the present-day networks can be explained almost exclusively through the mechanism of duplication and divergence. Novel interactions between proteins emerge on rare occasions. This principle seems to be universal in the evolution of species as it was confirmed by the data obtained from all species analysed in this study. This principle could also explain the dynamics of other biological networks and it explains special features of protein networks such as self-similarity (fractality) in a straightforward way.
Useful for the interpretation of genome sequences and evolutionary biology
The results of the joint research project of the University of Vienna and CUNY wi
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University of Vienna