I might give the octopuses a pass on not discovering fire.
Sure, now that they’ve evolved their thumbalogue they do.
in case that wasn’t obvious, I know lots of animals climb trees without anything like a thumb. Lions, for instance. But the panda’s “thumb” was developed for holding bamboo.
Hey, there’s even tree-kangaroos. There are also tree lobsters, but they’re an insect and unrelated to crustaceans. These don’t count.
I heard a scientist on CBC Radio discussing human evolution, who suggested the big brains we developed were for dealing with the workspace we used our hands in - the challenges of toolmaking and tool use helped create our brains, which then conveniently were useful to process more advanced speech too.
And why aren’t trees smarter? I mean, they are all surrounded by other trees.
Speaking of fire and trees, one hypothesis for the Fermi Paradox I came up with is that maybe it’s only by a quirk of terrestrial evolution that we have wood. Maybe on almost all other planets the local light gatherers use the equivalent of shell or horn for their stiffening structures, and there’s no handy source of good fuel for early intelligence.
If their photosynthesizers excrete oxygen, then there’s something flammable on the planet. Oxygen reacts with almost everything. It’s only the result of selection effects that we think of non-flammable substances as being common: They’re common on Earth only because that’s all that’s left.
Not necessarily very flammable. Wet meat burns very poorly.