Answer:
Evolution refers to the change in the structure of an organism with the passage of million of years.
Explanation:
Evolution is the change in the structure of an organism with the passage of million of years. Evolution occurs due to two reasons, first from genetically while the other from adaptation to the environmental conditions. In genetically, the change in structure of animal comes from their parents whereas changes occurs due to adaptation of an organism in order to survive in the harsh climatic condition of the environment.
Natural selection refers to the phenomenon by which the species in a population possessing the tendency to get adapted in a condition enhance in numbers in comparison to those who exhibit fewer adaptation capacities over a number of generations.
In other words, it can be stated as the non-random and differential development of distinct genotypes function to sustain favorable variant and to eradicate less favorable variants. Some of the conditions are required for the process of natural selection to take place.
These are heredity, reproduction, variation in individual characters, and variation in the fitness of organisms among the members of the population. If the conditions are met, then the phenomenon of natural selection occurs by default.
