Final answer:
Evolution in biology is the change in species over time, not individuals, influenced by processes like natural selection. It represents the genetic alterations within a population over generations, leading to the diversity of life forms.
Step-by-step explanation:
In biology, evolution refers to the change in species over time through a process such as natural selection. This genetic alteration over generations results from differential reproduction of individuals with certain alleles and not a change in the individual organisms themselves. The concept of evolution explains how populations acquire adaptations and diversify from a common ancestor, leading to the biodiversity we see today.
Evolution does not pertain to changes in individuals during their lifetime, which is a process of development, nor does it directly explain the origin of life. Rather, it is the change in the genetic makeup of a population over time. One can observe this in phenomena such as the changes in bill size among finches, where the shift in average bill size after several years indicates evolutionary change.