Evidence of the octopus evolution show it would have happened too quickly to have begun here on Earth. “Thus the possibility that cryopreserved Squid and/or Octopus eggs, arrived in icy bolides several 100M years ago should not be discounted as that would be a parsimonious cosmic explanation for the Octopus’ sudden emergence on Earth 270 ma BP.”

2022-01-29:

3 hearts, pumping blue-green blood because their oxygen carrying metal is copper (versus iron in the heme of our blood). They can spend 30 minutes out of the water, to scoot between tidepools.

Alien intelligence: from a distant branch in the tree of life, the octopus is the only invertebrate to have developed a complex, clever brain. Our common evolutionary ancestor is a tubule so ancient, neither brains nor eyes yet existed. They evolved independently, on land and by sea. From the Cambrian explosion of sensing, body plans, and predation, minds evolved in response to other minds. It was an information revolution. It’s where experience begins.

The octopus brain rings around its throat. 500M neurons, similar to dog (vs. human: 86B, fly: 100K).

The octopus has over 50 different functional brain lobes (versus 4 in human)

And furthermore, 60% of its neurons are out in the arms, with a high degree of autonomy. A severed arm can carry on as if nothing has changed for several hours.

It is a distributed mesh of ganglia (knots of nerves) in a ladder-like nervous system. Recurrent neural loops serve as a local short-term memory latch.

“The octopus is suffused with nervousness; the body is not a separate thing that is controlled by the brain or nervous system.” Unconstrained by bone or shell, “the body itself is protean, all possibility. The octopus lives outside the usual body/brain divide.” (PGS)

Structurally, our eyes ended up strikingly similar to the octopus (camera-like with a focusing lens, through a transparent cornea and iris aperture to a retina backing the optic nerves). But octopus eyes have a wide-angle panoramic view, and they move independently like a chameleon.

Their horizontal slit pupil stays horizontal as the body moves, like a steady cam. This is made possible by special balance receptors called statocysts (a sac with internal sensory hairs and loose mineralized balls that roll around with movement and gravity).

They can see polarized light, but not color (making their color-matching camouflage skills all the more intriguing; they also see with their skin).

Their playful interactions with humans exhibit mischief and craft, a sign of mental surplus

Humans internalized language as a tool for complex thought (we can hear what we say and use language to arrange and manipulate ideas). Octopuses are on a different path.

Their entire skin is a layered screen, with about a megapixel directly controlled by the brain.

Skin color, pattern and fleshy texture can change in 0.7 seconds.

3 layers of skin cells control elastic sacks of pigments, internal iridescent reflections, even polarization (which the octopus can see), over a white underbody. They are regulated by acetylcholine, one of the earliest neurotransmitters in evolution.

The octopus can create a voluntary light show on its skin, e.g., a dark cloud passing over the local landscape, or a dramatic display to confuse a predator while fleeing.

30 ritualized displays for mating and other signaling.

Some octopuses have regions of constant kaleidoscopic restlessness, like animated eye shadow.

1600 suckers. 16 kg of lift capacity per sucker. 10k tasting chemoreceptors per sucker. Each is controlled individually.

Octopus muscles have radial + longitudinal fibers (agile like our tongues, not our biceps).

Opposing waves of activation can create temporary elbows at the region of constructive overlap, or pass food sucker-to-sucker like a conveyor belt.

The octopus’ arm muscles can pull 100x its own weight.

It can squeeze through a hole about the size of its eyeball.

Their ink squirts contain oxytocin (perhaps to soothe prey) and dopamine, the “reward hormone” (perhaps to trick predators that they had caught the octopus in the billowy cloud).

2022-02-17:

Soft-bodied cephalopods such as the octopus are exceptionally intelligent invertebrates with a highly complex nervous system that evolved independently from vertebrates. Because of elevated RNA editing in their nervous tissues, we hypothesized that RNA regulation may play a major role in the cognitive success of this group. We thus profiled mRNAs and small RNAs in 18 tissues of the common octopus. We show that the major RNA innovation of soft-bodied cephalopods is a massive expansion of the miRNA gene repertoire. These novel miRNAs were primarily expressed in neuronal tissues, during development, and had conserved and thus likely functional target sites. The only comparable miRNA expansions happened, strikingly, in vertebrates. Thus, we propose that miRNAs are intimately linked to the evolution of complex animal brains.