Answer:
A change occurs in the environment.
Poorly adapted individuals have decreased survivorship.
Well-adapted individuals leave more offspring than do poorly adapted individuals.
Genetic frequencies within the population change.
Explanation:
Natural selection is a mechanism for the evolution of populations under the changed climatic conditions. The presence of genetic variations is a required factor for natural selection. As the conditions of habitat are changed, some of the genetic traits become more beneficial for individuals than the other.
The individuals of the population with beneficial adaptive traits have increased survival and reproductive success. On the other hand, the individuals that lack those adaptive genetic traits have reduced survival. Individuals with increased survival success leave more progeny. Over generations, a new population evolves that has the most number of individuals with beneficial genetic traits.
