It is often suggested that traditional models of artificial evolution, based on explicit, human-defined fitness functions, are fundamentally more restricted and less creative than natural evolution, in which no such constraint exists. After a discussion and refinement of this statement, we suggest a classification of evolutionary systems according to their evolutionary "creativity". We describe an environment, called Evosphere, in which a population of 3D creatures interact, fight with each other, and evolve freely on the surface of a "microplanet". We demonstrate the onset of natural selection and adaptive evolution within this virtual world, both by visual in