The idea of life on other planets is fun to contemplate, but hard to imagine. Usually, aliens are depicted as big-eyed monsters focused on probing unsuspecting humans. But philosopher Peter Godfrey-Smith thinks we need to look no further than the ocean to get an idea of what intelligent life on other planets might look like. His example of alien life on Earth? Octopuses.
Octopuses are some of the smartest animals on Earth. They can tell humans apart even if they're wearing the same outfit.
And you've probably heard about a few of their brilliant escapes from aquariums and jars.
Like humans, octopuses can be petty, too. They've been known to squirt water at a lightbulb until it short-circuited. This cheeky habit became so expensive at the University of Otago in New Zealand that the octopuses had to be released back into the wild.
They also make enemies.
One octopus in a research lab decided, for no particular reason, that it didn't like one of the lab workers and would squirt her, and only her, with water whenever she walked by.
Octopus and human brains have roughly similar numbers of neurons proportional to our size, but they're divvied up differently in an octopus's brain. For one, octopuses have neurons in their arms — their arms may even have their own memories.
Octopuses are the most complex animal with the most distant common ancestor to humans.
Our evolutionary paths most likely diverged at just, oh, an early leech or flatworm. Not exactly cousins.
Octopus brains and humans brains evolved along completely different paths. Both species ended up being intelligent anyway. Godfrey-Smith believes that humans and octopuses have something else in common, too: consciousness.
There's no clear way to prove consciousness. Octopuses' curiosity and awareness of their surroundings suggests to Godfrey-Smith that the cephalopods have a sense of "what it's like" to be an octopus, though.
Godfrey-Smith says that if there is conscious life on other planets, it would have of course risen independently from humans, too.
So octopuses may be the closest look we'll get at what alien life might be like ... at least for now.