Imagine a world where a creationist situation holds: God (or an alien master species, if you prefer) created all the species you see in the world today, and there will never be any others. 

Are there any real world, science based mechanisms that could prevent evolution, and allow this world to persist without speciation? I want to avoid continuous intervention by the creator.

This question was inspired by [Would there be evolution on a perfect world?](https://worldbuilding.stackexchange.com/questions/26115/would-there-be-evolution-on-a-perfect-world)