2 claims in “evolutionary biology, cognitive science”
Intelligence took a long time to evolve in humans and remains rare because direct genetic encoding of solutions is always more efficient and adaptive than general-purpose search processes, which are expensive, unreliable, and slow (taking whole days to learn).
Human-level intelligence is rare and took a long time to evolve because small Turing machines could always be encoded more directly and efficiently by genes with sufficient evolution, making specialized hardcoded solutions superior to the costly, slow, unreliable search process that intelligence requires.