1. ICREA-Complex Systems Lab, Universitat Pompeu Fabra, Dr. Aiguader 88, Barcelona 08003, Spain
2. Institut de Biologia Evolutiva (UPF-CSIC), Pg. Maritim 37, Barcelona 08003, Spain
3. Santa Fe Institute, 1399 Hyde Park Road, Santa Fe, NM 87501, USA
4. European Centre for Living Technology, S. Marco 2940, 30124 Venice, Italy
5. Evolution of Technology Lab, Institut de Biologia Evolutiva (UPF-CSIC), Pg. Maritim 37, Barcelona 08003, Spain