I think there are very many things about Earth that are underappreciated as possible limiting factors.
I think that plate tectonics is absolute prerequisite for life to evolve. Not only that, you need to have plate tectonics for a very long time for life to evolve. You need sharp temperature gradients stable for very long time on geologic scales and you only get that with plate tectonics. Without plate tectonics and with presence of atmosphere and voluminous bodies of water (other requirements) everything just gets obliterated quickly and the entire planet becomes flat without much features or temperature gradients. At later stages of evolution I think geographic features are important as they create niches which promote specialization and differentiation.
I am currently reading on origins of political order (https://www.audible.co.uk/pd/The-Origins-of-Political-Order-...). I think it might be possible large brain and high intelligence are not inevitable evolutionary results. The author speculates, and very convincingly, that the intelligence is result of human and chimpanzee males and females having different goals that cause them to deceive each other. The one who could better deceive would have evolutionary advantage and this caused humans to grow in intelligence as a result. But this level of intelligence is not inevitable as we see other species dealing with the problem in different ways. Large brain is a huge liability to an animal as it consumes a lot of energy and causes lots of other issues. It is true that animals use large brains to avoid predators or, being predators, to be more effective at the task. But it also seems that most animals don't seem to be growing their brains more with relation to their body size as it seems there are diminishing returns at some point and bigger brain costs exponentially more than it is worth.
I think that plate tectonics is absolute prerequisite for life to evolve. Not only that, you need to have plate tectonics for a very long time for life to evolve. You need sharp temperature gradients stable for very long time on geologic scales and you only get that with plate tectonics. Without plate tectonics and with presence of atmosphere and voluminous bodies of water (other requirements) everything just gets obliterated quickly and the entire planet becomes flat without much features or temperature gradients. At later stages of evolution I think geographic features are important as they create niches which promote specialization and differentiation.
I am currently reading on origins of political order (https://www.audible.co.uk/pd/The-Origins-of-Political-Order-...). I think it might be possible large brain and high intelligence are not inevitable evolutionary results. The author speculates, and very convincingly, that the intelligence is result of human and chimpanzee males and females having different goals that cause them to deceive each other. The one who could better deceive would have evolutionary advantage and this caused humans to grow in intelligence as a result. But this level of intelligence is not inevitable as we see other species dealing with the problem in different ways. Large brain is a huge liability to an animal as it consumes a lot of energy and causes lots of other issues. It is true that animals use large brains to avoid predators or, being predators, to be more effective at the task. But it also seems that most animals don't seem to be growing their brains more with relation to their body size as it seems there are diminishing returns at some point and bigger brain costs exponentially more than it is worth.