Modern man uses the method of conscious selection in his selection work. It lies in the fact that the breeder sets himself a specific task and conducts selection on one or two grounds. This approach allows you to achieve great success in a relatively short time. Primitive people did not set themselves the goal of developing any particular breed or variety. But they used the worst animals and plants for food and, on the contrary, preserved valuable organisms (the most dairy cow, chickens that carry large eggs). This method is called unconscious selection. Its value and the rate of formation of the variety (breed) is much lower.
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.