Here's why:
* Evolution is an ongoing process: Evolution isn't a one-time event. It's a continuous process driven by factors like:
* Mutations: Changes in an organism's DNA.
* Natural Selection: Organisms with traits better suited to their environment are more likely to survive and reproduce.
* Genetic Drift: Random changes in gene frequencies, especially in small populations.
* No "end state" for evolution: There's no perfect or final form for any species. Evolution is constantly shaping and reshaping organisms in response to their environment.
* Even slow changes are evolution: Evolution can happen slowly, sometimes over millions of years. Even small changes in gene frequencies over time can lead to significant differences between generations.
Example: We might not see dramatic changes in a human's lifespan in a single generation, but over thousands of years, human evolution has led to changes like increased brain size, improved ability to digest lactose, and adaptation to different climates.
In short, all animals are constantly evolving, even if the changes aren't always noticeable in a short timeframe.