Octopuses, squid, and cuttlefish are among the smartest invertebrates, rivalling mammals for complex behavior that can include delaying gratification, having good memories (even in old age), and getting emotional about pain. Yet they are related to life forms like the nautilus which displays no such qualities.
Even compared to each other, the genomes of three cephalopods studied had been broken up and extensively reorganized:
Looking to solve the mystery, researchers began to examine the genomes of the two-spot octopus, the Boston Market squid, and the Hawaiian bobtail squid. And that’s where they discovered something interesting. Squid genomes were arranged differently from those of similar life forms.: …
The scientists admit that they don’t know just how breaking up and reorganizing the genome results in increased intelligence but it is a promising research avenue.News, “Can largely rearranged genomes explain why octopuses are smart?” at Mind Matters News (May 17, 2022)
Takehome: It’s still not clear just how intelligence develops in a life form. The relationship between massive genome rearrangement and very high intelligence in an invertebrate remains unclear but it is a promising research avenue.
You may also wish to read: Octopuses get emotional about pain, research suggests. The smartest of invertebrates, the octopus, once again prompts us to rethink what we believe to be the origin of intelligence. The brainy cephalopods behaved about the same as lab rats under similar conditions, raising both neuroscience and ethical issues.