Pretty interesting discussion on evolution here...nice!
I love taking thought experiments in this realm.
For example, intelligence/success on Earth is shaped by a volatile and ever-changing climate. The species that have survived the longest or have covered more the planet surface are creatures most capable of adaptation to environments. Us humans, have achieved what we believe to be the apex of intelligence/success on Earth. Though our abilities of abstraction we are able to make predictions and prepare accordingly. A few animals exhibit glimmers of this but no animal has quite gone as far to make even the short-term predictions humans can make.
Now, what if we are looking at a stable planet. Has existed just as long as Earth and has very similar conditions and composition except for volatility. Let's say that tectonic activity is either dead or very mild, orbit around its star is un-perturbed by an excess of other objects, the planet is well protected from impact either from a helpful planet nearby or the system was just clear of many objects and the star is an unremarkable but incredibly consistent (temperature) and long lived dwarf star.
Without that occasional kick in the pants, does life on this planet ever evolve beyond bacteria? How much of evolution is driven by pure competition between hunters and the grazers and how much of it is from being better at surviving a changing world. I think it is tough to think along this path because we are children of that volatile and violent world. Our entire perspective and understanding of the universe is completely shaped by those facts. Anyway, in my fantasy scenario above, I'd predict it would be dominated by mega-fauna (dinosaurs). The competition race just amps up over the billions of years and hunters and grazers just get bigger and bigger with no catastrophic changes that invalidate that path.