There are two variations of cazoinks, multi-color and brown. Brown cazoinks have better fitness because they blend in better with the territory. This means multicolored cazoinks are rare and more likely to be eaten by birds
Over time the population of brown cazoinks grew and the population of multicolored cazoinks continued to fall due to fitness levels
One day there was a devastating earth quake which separated the brown cazoiks from the multicolored cazoinks. The brown cazoinks continued life as normal but the multicolor cazoinks would slowly adapt to their new environment
Tens of thousands of years later the multicolored cazoinks have adapted totheir environment and become a new species separate from the brown cazoinks.
Oh no another earthquake!
Together again, the two species of animals were closely related enough to reproduce together. However, the brown cazoinks did not mate with those who made the mating call the white species made so they remained two separate species.