What evolutionary factor plays a decisive role in shaping adaptations?

The adaptation or adaptation of living things to the factors of wildlife occurs mainly through natural selection. It works like this: in a group of certain organisms, multiple offspring appear. Due to hereditary variability, different individuals of the group receive dissimilar genetic prerequisites for survival. If the genetic traits are unfavorable, the organism dies, and if they are favorable, it grows and also multiplies. The favorable traits are passed on to the offspring and become resistant in the given species.