Two studies published in the latest issue of Science, led by Dr. Fernando García-Moreno, Ikerbasque researcher at the Achucarro Basque Center for Neuroscience and the University of the Basque Country (UPV/EHU), along with collaborators, have revealed that birds, reptiles, and mammals have developed complex brain circuits independently, despite sharing a common ancestor. These findings challenge the traditional view of brain evolution and demonstrate that, while comparable brain functions exist among these groups, embryonic formation mechanisms and cell types have followed divergent evolutionary trajectories.