Witness the The Fall and Decline of the Animal Kingdom. It's not what you think -- it's what you don't usually think about: that in terms of sheer numbers animals are a minority in the vast ocean of life that inhabits the oceans and lands of this world.
Doesn't this suggest that it takes so, so, so many permutations of Genetic Arrangements to create even the simplest eukaryote? That's the advantage of a 3plus billion years time frame.
By the way, check out the Interactive Tree of Life and mouse over Homo Sapiens. Lovely picture. No wonder the neighbouring Pan troglodytes look so shocked.