Thanks to heredity, the conservation of species is ensured over significant periods (up to hundreds of millions of years) of time. However, environmental conditions change (sometimes significantly) over time, and in such cases, variability, leading to the diversity of individuals within the species, ensures its survival. Some of the individuals are more adapted to new conditions, this allows them to survive. In addition, variability allows species to expand the boundaries of their habitat, to develop new territories.
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.