Viruses adjust the course of evolution. Viruses, using pandemics, exterminate and weaken certain phenotypes that no longer participate in the evolutionary process.
About 20% of human genetic material is introduced by viruses. Sometimes viral genes become cellular genes.
Viruses can not only change the genetic apparatus of a cell, but also exchange genetic information within a species and between different groups of organisms. In a changing environment, this is a powerful evolutionary mechanism. That is, viruses stimulate evolutionary processes in the biosphere.
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.