Find examples that prove the manifestation of the stages of the historical development of the animal world in the individual development of man. 

During embryonic development of birds and mammals, including humans, gill slits appear in the pharynx and corresponding partitions. The fact of the laying of parts of the gill apparatus in embryos of terrestrial vertebrates is explained by their origin from fish-like ancestors who breathed gills. The structure of the heart of a human embryo resembles during this period the structure of this organ in fish.
Similar examples indicate a deep connection between the individual development of organisms and their historical development.


Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.