Map of the first human migrations , according to studies on mitochondrial DNA. The numbers represent the millennia until today. The accuracy of the map is disputed

At the beginning of time, on a blue planet in a solar system, our Earth , the only known planet that can maintain the atmosphere and liquid water, the conditions necessary for the appearance of life were formed. 4 billion years after the formation of this planet, a species unique was born. 10 million years ago, the formation of mountain ranges (like the Himalayas ) or the formation of the Great African Rift disrupted weather patterns, causing a systematic cooling of the planet, which would become a favorable situation for the emergence of this new species that will dominate the planet. 7 million years ago, our ancestors, primates ^[33], they lived quietly, in trees, in the tropics, in the dense African jungles. But their area would be invaded. This newcomer would have a profound effect on history: grass. In East Africa , grasslands have invaded the traditional forest habitat of primates. With fewer trees and as much space as possible between them, primates have had to adapt. With more and more primates in trees and as little food as possible, primates they had to walk from one food source to another, separated from the meadows. In search of available food, many primates descend from trees and adapt to the new habitat, gradually and slowly adopting bipedal gait, with upper limbs with which we can model history and build civilization.

3.2 million years ago, a unique creature and distinct from other animal species, stepped into the lands of today's Ethiopia. Her name was Lucy and came from the species Australopithecus afarensis . He was 25 years old, a reduced height of 1.07 m (about the size of a modern 6-7 year old child), weighed about 28 kilograms and had a low cranial volume (3–400 cm³). Its main features were the bipedal position, being able to use its upper limbs as a pendulum. It had no landscaped habitat or tools; she probably behaved like a small hunter with a strong penchant for cooperative hunting and was a picker of fruit, mushrooms, or roots. She is considered to be the real "Eve" - ​​the mother of all people. ^[34]Her first bipedal steps represent the beginning of a long journey of humanity.

2.4 -1.5 million years ago, the first proto-humans or hominids stepped on an earth whose rocks are full of silicon elements (the second chemical element on the planet's crust), through contact with oxygen having the ability to form crystals, which combined to create solid rocks, rocks that could be carved and adjusted without breaking. Individuals from the species Homo Habilis ^[35] (whose cranial volume now ranged from 500 to 800 cm³ and who were about 127 cm tall and weighed about 45 kg) could obtain sharp edges that were used as tools. built either as hunting weapons or for chopping prey. Thus began the first technological revolution: the Paleolithic or Stone Age .