Final answer:
The changing environment plays a crucial role in an organism's evolution, with natural selection favoring those with beneficial traits, leading to a change in the population's genetic makeup. Coevolution among species also exemplifies this influence. Evolution through mutations allows for adaptation but does not have intentional direction.
Step-by-step explanation:
The role of a changing environment in an organism's evolution is significant. Organisms do not evolve intentionally; rather, evolution is a response to environmental changes that affect which phenotypes are more likely to survive and reproduce. In a population, those individuals with advantageous genetically determined traits will tend to produce more offspring, hence altering the genetic makeup of the population over time. This process is guided by natural selection. Additionally, coevolution occurs when species in symbiotic relationships evolve in response to each other's changes. The vast diversity of life on Earth, including variation within species, can be attributed to the mutations that facilitate adaptation to ever-changing environments, showcasing the lack of a predetermined direction in evolutionary processes.
Examples of how the environment influences evolution include the way that fossils show how past organisms differed from those today and had to adapt to different conditions, or how recent scientific studies have demonstrated that the evolution of subspecies can directly affect the ecosystems they inhabit.