A qualitative leap in the transformation of a monkey into a man took place about 2 million years ago and was associated with the manufacture of the first primitive tools of labor.
In appearance and structure, a skilled man did not differ from great apes, but he already knew how to make primitive tools from pebbles.
A skilled man had an ape-like appearance: a short body and long arms. The height was approximately 150–160 cm.
Homo sapiens differed from australopithecines in a relatively large brain volume (about 700 cm³), enlarged frontal and parietal lobes.
The tools of labor of a skilled man were stone, roughly worked. Stones were the main materials for the manufacture of tools and protection from predators.
A skilled person was engaged in gathering and hunting.
Natural selection contributed to the survival of individuals and groups with skills for work.
The next stage in human evolution was Homo erectus, who lived on Earth from 2 million to 500 thousand years ago.
Homo erectus had an average height (150–160 cm), a straight gait and an ape-like skull with protruding supraorbital ridges and a sloping chin. The brain volume reached 900–1200 cm³.
Representatives of this species made stone tools and took refuge in caves. They knew how to maintain fire, but they could not get it. They lived in small groups.