Final answer:
Evolution is the process responsible for species changing over time, potentially creating new species through mechanisms like genetic variation and natural selection. Adaptations result from this process, enabling better survival and reproduction in changing environments, leading to the evolution of species.
Step-by-step explanation:
The process by which individuals of a species change over time and potentially become a completely different species is known as evolution. Specific mechanisms like genetic variation and natural selection are key to this process. To illustrate, the beak sizes of Darwin's finches have evolved due to different-sized seeds being available, which is an example of adaptation. Adaptation enables organisms to survive and reproduce better in their changing environment, leading to changes in the gene pool of the population over time.
Moreover, allopatric speciation is a type of evolution where geographical barriers lead to the separation of members of a species, eventually resulting in the formation of new species. This is an example of vicariance, where speciation occurs due to the environmental separation of populations.
As environments change, traits that were once advantageous can become less favorable, demonstrating that evolution is not goal-directed but a response to environmental pressures. The outcome of evolution depends on existing genetic variation and environmental conditions, which are not static, thus shaping the evolutionary trajectory of species.