your question really asks about the rules of inheritance and abstract classes, and does not apply to real world examples.
The world doesn't necessarily 'classify' easily; we cannot organize what 'the world' consists of in a finite way. so there IS no inheritance nor is there real classification except in the loosest sense of the word.
remember -- OO is based on classification, a way of organizing information for OUR understanding. We do not understand what 'the world' is in every definition (macrocostic to microcostic) so it makes for a bad example.
just because we are of the world, doesn't mean we are the world.
instead, the world is comprised of us. that's the real gotcha.