iirc if our guts had developed to handled meats a little better in their raw state, the increased enegy demands for the gut itself would make higher brain function trickier.
So, cooking food, to get nutrients that our crappy guts can digest. Oh, but before cooking, tool using.
The first proto-hominid that managed to use a rock to crack open a bone that even the hyenas could not devour opened an energy gap for those monkey-brain scavengers. Able to access a food source that nothing else was out-competing them for, the increase of fats and proteins (from delicious marrow) led to human beings that were smarter and stronger, ready to move up the food chain.
(all of this based on the best science / guesses we have developed so far)
So, tool use as a shortcut to being sabretooth chow less often, then preparing and cooking food to overcome the shortcomings in our system and give those developing brains lots of juice (the better to learn how to Rip And Tear)>>13087391
this is a good point. the modern octopus is refined and evolved, specialized into its role by chemistry. Just as we humans would face insane hurdles trying to go live in the ocean without bones and with a different blood chemistry, an octopus seems to be lacking in developmental slack, would have a hard time finding something that can change/allow it to move into a widely different niche.
Would be interesting to see how an octopus would develop over time, if we were able to short-circuit its destructive aging. We know they learn, what happens when they have time to learn more?