Octopus: The Nearest We Get to Meeting an Alien
OTHER MINDS The Octopus, the Sea, and the Deep Origins of Consciousness
By Peter Godfrey-Smith
Illustrated. 255 pages. William Collins £20
Review by Graeme Gourlay
The majority of animals we encounter underwater are strangely distant - fascinating to observe but barely aware of us and, even when they do react to us, it is either a very basic defensive stance much as a nipping damselfish warning us off, or, more often than not, the most primitive urge of all - a rapid retreat.
Most of the time, however, we are ignored. It is one of the tantalising delights of diving. You can be extremely physically close to wild animals - far closer than is normal topside, but it as if you inhabit a different dimension and you are observing them across some mysterious divide.
There are some notable exceptions. Manta rays seem to break all the rules for fish and actively engage you - no doubt, that is why we seek them out and cherish them so much. They seem so much more alive than even the most inquisitive shark or grouper.
Marine mammals are obviously in a different category. The first time you met a dolphin that wants to play is an unforgettable experience. I’ve been with grizzly, cynical dive professionals who have been reduced to open-mouthed awe after such encounters. And we all know that seal cubs can be as delightful as puppies.
But these interactions are so wonderful because of their very rarity. Most of the time we spend our dives alone underwater - mesmerised, but alone.
But there is one other group of creatures that can seem to reach across the divide and let us into their world, that seem to communicate with us, or in some strange manner involve us in their business. Cephalopods. And they are the most alien and intriguing of all the encounters you can have while breathing through a regulator.
Just what is an octopus up to when it tentatively reaches out an arm to probe and investigate us, or, if you are really lucky, brazenly slither all over you, your mask and other equipment as it makes contact across the divide?
You can’t but wonder what a cuttlefish is saying to the outside world as it runs through the gamut of multi-coloured display on its startling body. And most divers have had the creepy feeling of being watched and suddenly focusing on the octopus eye that is so intently spying on you.
I’m not alone in pondering whether octopus and to a lesser extent cuttlefish are intelligent. Different, but unlike most of the things we come across while immersed, definitely sentient and engaging with their environment and, occasionally us, in a way we recognise.
Philosopher of science and diver Peter Godfrey-Smith came to the same conclusion and the result is this fascinating book which, from that starting point, takes us on a journey through evolution, our understanding of intelligence and onto the implications for that daunting enigma - consciousness, human or otherwise.
It all started a very long time ago. You have to go back to before the Cambrian period before you can find our common ancestor with cephalopods. More than 600 millions years ago our very separate evolutionary journeys began. From a fairly basic worm-like entity on the ocean floor, one strand of life branched off into what was to become mollusks including cephalopods and arthropods such as ants and lobsters and another into what would become vertebrates from which humans and fish evolved.
‘If we can make contact with cephalopods as sentient beings, it is not because of a shared history, not because of kinship, but because evolution built minds twice over,’ says Godfrey-Smith. ‘This is probably the closest we will come to meeting an intelligent alien.’
You can see why the makers of Arrival, the latest Hollywood film about aliens coming to Earth, chose benign seven-legged giant octopus as the friendly but misunderstood visitors.
But the real world is far more remarkable than fiction. The story of how such different stands of intelligence evolved on our planets is truly wondrous.
Only three of the 34 animal phyla - basic animal groups - evolved into what is known as complex active bodies. That is arthropods, chordates (animals like us which have a nerve cord down their back) and one group of mollusks - the cephalopods. And it is those bodies and how the react and adapt to their environments from which intelligence grew.
The body of an octopus is a very special thing. Godfrey-Smith lucidly explains how their ancestors evolved defensive shells and became the first predators in the ocean. The frills of their bodies extending from the shells developed into tentacles and they left the confines on the ocean floor to swim in search of prey. About 290 million years ago they discarded their shells with the advantages of the speed and stealth outweighing the need for defence against other, bigger predators.
There are very few hard elements in an octopus’s body. A ‘body of pure possibility’ which can squeeze through holes the size of their eye ball. They have a comparable number of neurons to mammals but organised in a very different manner, more diffuse and spread through their bodies particularly in their probing, searching legs which have their own memories.
This curious hunter has evolved to roam the ocean floor - darting into crevices, exploring anything unusual in the search for food, relentlessly searching its environment. Godfrey-Smith watched his dive partner as ‘an octopus grabbed his hand and . . . Matt followed, as if he were being led across the sea floor by a very small eight-legged child.’ Ten minutes later they arrived at the octopus’s den.
There is plenty of evidence that octopus can recognise individuals, even taking a dislike to some people, blasting them with squirts of water when they walk past in laboratories. They can escape confinement and seem aware when someone’s back is turned.
However, another of the many surprising things about this excitable bundle of malleable neurons is that they only live for a year or so. Godfrey-Smith takes us through a quick tour of the latest theories of ageing and the evolutionary benefits of both short and long lives and it soon makes complete sense that these ‘big bang’ reproducers die soon after their sole act of procreation. In the process, he sheds light on the nature of ageing for us all.
That is the key conceit for this entrancing book - first he engages you with charming information about the weird world of cephalopods, then he explains the latest research and theory and at the same makes you think about the implications this has for our understanding of all life - particularly our own. He grapples with the nature and development of language, the construction of intelligence and right up to subjective awareness and consciousness. He does all of this with a playful intelligence and wonder that mirrors the most inquisitive cephalopod. A delight on so many levels.