Until we can go back in history and learn about the beginnings of mankind, we will have to make do with scientific assumptions based on the study of fossils of the pre-humans (Hominids), and Early Man. Science dates the beginnings of man with discovery of fossils that can be carbon-dated, and measured to determine the characteristics and life-style of early humans.
Early Man was different from other primates when the species Homo emerged. Man was bipedal - which means he walked on two legs. Man had developed a larger brain and smaller teeth. His head was attched to his backbone in an efficient way for walking on two feet.
The earliest human beings were omnivores. Man's diet consisted of both plants and animals. Man used fire for cooking and warmth. Man used tools to kill and butcher meat.
Mankind had learned how to form a working group for hunting and gathering food. The earliest humans built simple shelters from the elements. As Mankind migrated, he developed skills and characteristics for survival in his environment.
Development of Hominids and Early Man
Timeline For Human Innovations