125 At the concert . As a bowed instrument follows the notes of the piano to speed up its musicality, during the evolution of Hominins some entries were necessary in order to determine their development and, over millions of years, their colonization of the desired land. Not everyone is still in agreement, but the divine plan involves precisely that the path of the earth and its inhabitants is nothing other than the result of a constant change, of adapting and relating in harmony and respect for mutual benefit. Thus, man evolved, and millions of years earlier so did the egg, able to develop through a mineral shell so as not to dehydrate nutrients and the foetus, allowing the first reptiles to come out, live and reproduce out of the water and to become hens too. As Jonathan Silvertown explains in Dinner with Darwin. Food, Drink and Evolution (ed. The University of Chicago press, 2017), from an evolutionary point of view, egg was born much earlier than the chicken. Along the development paths of all species there have been additions, but also subtractions: as when, 2 million years ago, the ancestors of Homo Sapiens lost from the gene pool the MHY16 gene, the one that gave brute force to the mandible. Approximately during those years, in those lands that today correspond to Ethiopia, Australopithecus gave way to the Homo chain which, in the meantime, discovered something. Something that finally led him to travel. Nothing paleontologically proven, but a coincidence that cannot be left to chance. The discovery is about cooking food, the consequence is the progressive reduction of the digestive system in the face of an increase in brain mass , the coincidence is that while increasing his brain capacity, man's progenitor began to travel far from native Africa. Between 2 and 4 million years ago, in this strip of Africa, the Homo species put itself on the trail of Australopithecus, took his characteristic features, but began a morphological change linked to two functions: the digestive and the cerebral ones. Still to that gap of millions of years, stone instruments and finds of other nature are traced back, first hint of meat processing and food cooking. Habilis is the first species of the Homo genus to interpret this evolution, his mandible is similar to that of the Australopithecus, but the skull is more voluminous. We are talking about 2.3 million years ago. 350 thousand years pass, and Homo Erectus appears to us as the first with the habit of cooking food. He is certainly omnivorous, and not just herbivorous like his predecessors; his dentition becomes smaller and smaller, like his ribcage, while skull and brain increase. These latter characteristics, which make the Hominins in question increasingly similar to the Sapiens one, materialize with paleontological certainty 1.5 million years ago. Cooking food and a fully formed Homo Erectus are evidences inscribed in this period by the primatologist of the University of Harvard Richard Wrangham , in the book Catching fire: how cooking made us human (ed. Profile books, 2009). It is not certain that, in his early days, Homo Erectus cooked meat; the clues available fail to constitute evidence. What is certain is that this species accepted the entry. While Habilis’ and Australopithecus’ physical characteristics disappear from the DNA of the Hominins to come, the Erectus changed the rules of the game. His chest is certainly too small to contain the intestine of Lucy, the most famous Australopithecus in the world, and his skull is significantly larger. The connecting link stands in the cooking practice . It is not clear when and why, but by applying cooking to the preparation of vegetables and meat, Homo Erectus knew a significant increase in the energy value of food, managing to save energy from digestion – therefore meters of intestine, colon and stomach – all in favour of the only thing that has grown in the meantime: the brain. Cooking food has opened up a new world in front of the evolution of Homo Erectus, offering him the physical and mental abilities that led him far away from the home of all of us. While the previous species did not move away from their lands of origin, there are traces of Erectus thousands of kilometres far from the Horn of Africa. Cosmopolitan is the adjective that, for hyperbole, Jonathan Silvertown places beside him. In Dmanisi, in the Caucasus, some rests of Erectus were discovered, to date considered evidence of the journey that this species undertook from Africa, covering the Mediterranean areas westerly and reaching easterly the current China territory. From herbivores to omnivores, from raw to cooked food, from sedentary to explorers, the passage has been consumed within these blocks from half a million years ago. All signed by the Erectus. In these evolutionary steps lies the development of the brain , sump pump of that energy released by the digestive function thanks to cooking. This theory finds approval in the scientific community, and ethiopia - tanzania eurasia