What is the reason for the crisis of classical Darwinism at the beginning of the 20th century?

At the beginning of the XX century. G. Mendel’s laws were rediscovered, genetics began to develop. However, its achievements due to misinterpretation were used to criticize Darwinism.

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.