Other Minds: The Octopus, the Sea, and the Deep Origins of Consciousness

by Peter Godfrey-Smith

Biologists distinguish between semelparous and iteroparous organisms. Semelparous organisms reproduce once, or in a single short season. This is also called “big bang” reproduction. Iteroparous organisms, like ourselves, reproduce many times over a more extended period. Female octopuses, in general, are an extreme case of semelparity—they die after a single pregnancy. A female octopus might mate with many males, but when it is time to lay eggs, she settles permanently into a den. There the female will lay her eggs, and fan and tend them as they develop. This one clutch can contain many thousands of eggs. The brooding might take a month, or several months, depending on the species and the conditions (things are slower in cold water). When the eggs hatch, the larvae drift off into the water. Soon afterward the female dies.

A marine research unit at Monterey Bay, California (MBARI), explores deep-sea environments with remote-controlled submarines that carry video cameras. In 2007 they were inspecting a rocky outcrop nearly a mile underwater, off the coast of central California. They saw a deep-sea octopus (Graneledone boreopacifica) moving around. Returning a month or so later, they found the same octopus guarding a clutch of eggs. They kept returning to the site to watch the progress of this clutch of eggs, and always found the octopus there. In the end they watched this one octopus for four and a half years. This octopus brooded her eggs for longer than any other known octopus is thought to live in total, and the fifty-three months it spent there is the longest egg-brooding period reported for any animal species. (For example, no fish is known to guard its eggs for more than four or five months.)

Much of life runs in slow motion in cold water.

The octopuses have built an “artificial reef” through their shell-collecting behaviors, and this seems to have led to an unusual social life developing, a life of high densities and continual interaction. One way to interpret our Octopolis observations is to think that they show that octopuses, of this species and perhaps others, are generally more social than people realize. Their signaling behaviors—the color changes, the displays—do suggest this. A growing number of other studies push in the same direction: they suggest that octopuses are more engaged with each other than had once been thought. In 2011, a study of a species closely related to our Octopolitans reported that octopuses could recognize other individual octopuses. A more controversial study from 1992 suggested that octopuses can learn by watching each other behave.

The mind evolved in the sea. Water made it possible. All the early stages took place in water: the origin of life, the birth of animals, the evolution of nervous systems and brains, and the appearance of the complex bodies that make brains worth having.

Overfishing began in the nineteenth century and continues, with more meager returns, to this day. The other problem the sea faces is chemical change. This is even harder to see and more global in its sources, and, as a result, even harder to fix. One example is acidification. As the CO2 concentration in the atmosphere rises due to burning fossil fuels, some of the extra CO2 dissolves into the sea. There it changes the water’s pH balance, pushing it away from its usual state of mild alkalinity. The metabolisms of a great many sea animals, including cephalopods, are affected by this, and there are especially serious effects on corals and other organisms that make hard parts out of calcium. Those hard parts soften and dissolve in the altered sea.

When you dive into the sea, you are diving into the origin of us all.