The book is the first attempt to determine the specific features of the environment of the ancestral homeland of mankind (rifts, earthquakes, volcanism, the richest deposits of uranium ores, etc.) p. ). The author suggests that the active manifestation of these features in the Pliocene, combined with geomagnetic inversions, created an area of increased radiation in East and South Africa. Radiation caused mutations and changes in the structure of the body (increase in brain volume, uprightness, disappearance of large fangs, etc.) p. ). A confused pre-human would have died if he had not moved on to systematic social and labor activities.