The mind of the octopus
The octopus is the closest we will come to meeting an intelligent alien. What can we learn from the encounter? Peter Godfrey-Smith*
One of the most amazing creatures of the sea is the octopus. Peter Godfrey-Smith, a philosopher of science and experienced scuba diver became fascinated by the octopus and presented some interesting views on this creature in his recent captivating book. His main question was: why has octopus followed such a strange route of evolution, completely different from that of birds and mammals?
Cephalopods (literally: ‘head footers), the family to which the octopus belongs have a history of half a billion year of evolution. Their early ancestor started as a mollusk that gradually transformed itself via various stages into the three common species of todays world: the Nautilus, the Cuttlefish and the Octopus. The early species lived on the seafloor, later came development of the arms to lift themselves from the seafloor. Cameroceras is one of the spectaculair intermediate stages; this was a giant predatory cephalopod with an estimated length of 18 feet (see insert). Early now extinct versions still had shells but newer forms gave op their shells, with Nautilus as an exception. Another species of which many fossiles still exist is Asterosceras, an Ammonite with a typical ram-horn shape. Asterosceras represents an earlier stage of the Octopus rather than Nautilus.
An amazing fact of the octopus is that this smart and complex creature has no skeleton and hard parts at all. This allows it to change the form and size of its body, for example to squeeze itself through narrow holes of only a few centimeters wide. The octopus nervous system is estimated to consist of 500 million nerve cells. Most of them are located in its arms and a motor ‘appendix’ of its brain. Unlike brains of vertebrates like mammals and humans there is no central brain that controls the limbs. The octopus arms are in fact its brain (see also the ways of an octopus).
This raises the question of consciousness that bugged the mind of philosophers since ancient times. Most of them see consciousness as an uniquely human quality. But modern scientists take an different point of view. For example, primate biologist Frans de Waal of the Yerkes Institute believes that intelligence and consciousness are not only tied to Homo Sapiens. So does diver-philosopher Peter Godfrey-Smith, who tries to unravel the type of consciousness that might reside in the octopus. Since its arms are its brain but also its agents or instruments, the octopus must be in a sort of hybrid situation. Its arms are partly self but but also partly non-self: agents of their own.
Perhaps animal intelligence and consciousness become less of a puzzle if we accept that intelligent behavior evolved in man as well as animal in different forms dependent on the specific demands of their environments. Think of the tree of life with a common ancestor but with various branches leading to unique and clever adaptations of even non-mammalian species. In the octopus intelligence is largely a ‘grasp, explore and sense’ intelligence. It does not use its intelligence for maintaining complex social interactions like humans and chimpansees. But octopi do have a highly exploratory and opportunistic style of interaction in their watery environment. They became clever, not because they shared a common history with mammals and humans, but because they followed an entirely separate branch in the tree of evolution. Genetically, meeting an octopus is indeed like meeting an intelligent alien, that is: a creature from the sea that had already gained intelligence long before the dinosaurs.
Octopi held in captivity have the reputation of mischief and escape. They have been seen to escape from their own aquarium, to walk around on the floor of the room and even to visit a neighbouring tank for food. There is even the story of an octopus squirting jets of waters against a lamp short circuiting the power supply, or against visitors of its tank! These anecdotes suggest that the octopus may adapt easily to its environment and even its human keepers. Unlike fishes they seem to have developed a sense that they they are inside, and their visitor outside the tank. They are also able to use new objects for their safety. In 2009 researchers in Indonesia were amazed to see octopi carrying around half coconut shells over the sea floor to use as portable shelters. All this makes the octopus also a nice subject to read to children
A final detail about the octopus and cuttlefish; they have a very short lifespan of around two years, and the females die after a single pregnancy. Which is strange for an animal that has developed such a complex nervous system and arms that virtually 'think' for themselves. One reason might be that the sea is a very dangerous environment for the adult cephalopod. A creature without bones or shell is an easy prey for sharp-toothed predators, especially since it must leave its hiding place to go out hunting itself. And it will need every clever form of camouflage and trick to stay alive, even for such a short period.
*Peter Godfrey-Smith. Harper. Other Minds. The octopus and the evolution of intelligent life. Collins Publisher.London. 2016