> That suggests that a tiger is just a tiger,
Not at all. Everything can come from variation (mutation, cross over) + elimination of the worst. It's just that 'worst' is not a global minimum. Are we as humans superior to animals in strength, agility, speed, etc? Not at all. But some distant ancestor had some bigger brain, and that gave it all the edge it needed compared to weak and dumber siblings that were eaten, while our ancestor hid on a tree.
When some animal mutated to be able to eat meat in addition to plants, it had some advantage and was less likely to be eliminated when food got scarce. That's all you need to eventually arrive at something tiger-like.
That said, some animals seem to have reached a local maximum: sharks haven't changed in millions of years, cockroaches seem pretty successful, too.
But there's nothing 'creative' about it.
