For animals, the concept of Ultimate Perfection lies in a stage of existence that is unforeseeable: a being that no longer needs to adapt. Evolution is an ever-changing process unique to each species it affects, and while it is very gradual, happening often over hundreds of years, we can look back to find the main stages of a species' evolution to pinpoint the times at which the original species faded away and became a new one. While it is important to note that all species are in a constant state of evolution at all times, the best example of the movement to attain Ultimate Perfection from an animal's position is through evolution to become the most well-developed animal: a race to become better habituated in an ever-shifting environment. Animal's Ultimate Perfection explores the split between species: for example, the evolution of pelycosaurs to therapsids. Pelycosaurs, such as the Dimetrodon, were reptile-like mammals, so-called due to being classified as a species from which the descendants evolved through a reptile-to-mammal evolution into "full" mammals. "Full" mammals implies the emergence of a single jawbone (as opposed to a reptile's many bones in the jaw), teeth that are differentiated for separate tasks (such as meat shearing rather than the fairly uniform grinding of plant matter)