Reviewed in the United States on February 26, 2021
Metazoa, Animal Life and the Birth of the Mind
Peter Godfrey-Smith, 2020
We are all descended from Protozoa, single celled animals that evolved over a period of several billions of years. We evolved from, single celled animals, Prokaryotes like bacteria, without a nucleus, which then evolved into Archaea, complex, single celled animals with a nucleus. Things started to get really interesting 600 million years ago when Metazoa, multi-celled, cooperative organisms came onto the scene and that is where this book picks up the story. Peter Godfrey-Smith is the author of the book “Other Minds” which chronicles the intelligent capabilities of the Cephalopods or Octopus and squids; creatures who evolved intelligence and self-awareness on a separate evolutionary path from the vertebrates. How did minds evolve? How did it coincide with the evolution of muscles, nervous systems and sensory organs? If you are interested in these questions, then you may be interested in this somewhat esoteric but illuminating book.
Do you dismiss crabs or insects as somewhat mindless, automatons with no self-awareness? Insects are members of the Arthropods that came into being 500 million years ago and which include crabs and shrimp. Smith considers shrimps and crabs he has encountered in his many underwater research expeditions on the reefs of Australia. He concludes that these creatures with eyes, multiple sensory and manipulative limbs are and must have a sense of self, a sense of who they are separate from other creatures and their environment. A fascinating example are decorator crabs who are a sub-species of hermit crab. Hermit crabs use the discarded shells of clams to hide and protect themselves but in the case of decorator crabs they take camouflage one step further by plastering their discarded shell homes with algae, sponges and in some cases poisonous anemones for further protection. A form of tool use? Obviously, they could not engage in this behavior without a sense of self, a sense of the nature of their environment and the motivations of others. Dismiss the mental capabilities of bees? Their brain consists of over one million neurons which enables sophisticated vision and smell, navigation and flight control capabilities as well as sophisticated social interaction and building capabilities.
Smiths long term study of Octopus centers around long term research at two sights off the coast of Australia where they live together in large communities, one nick named Octopolis and the other Octalantis. Before his research, Octopus were considered solitary creatures, but his long-term study shows many complex social interactions including not only aggression but habitat sharing and defense strategies. One amazing capability is the ability to instantly sense the color and texture of their surroundings and to instantly camouflage themselves by mirroring the surroundings in their own skin. Also mirrored are their emotions. If an Octopus turns deep red you know it is angry. Studying their sleep EEGs reveals brain wave patterns similar to vertebrates dream sequences. The content of their dreams seems to be reflected in changing skin patterns and colors as they dream. One fascinating unique characteristic of their mind is the hundred of millions of neurons distributed in their 8 arms. “Assuming that sensory information from the skin and suckers does get to the central brain as well as to local neural networks, the octopus becomes an animal with both a very expansive sensory surface and, from the brains point of view, a rather unpredictable one. As the arms wander, they will change the shape of the body and also encounter objects, surfaces, and chemicals that produce sensory events. This can happen in several arms at once. The Octopus does occupy a perspective, but a protean and perhaps sometimes chaotic one. When I try to imagine this, I find myself in a rather hallucinogenic place, and that is everyday life for an octopus”.
Most people would rather not admit this fact, but we, mammals, “are an offshoot of the fish part of life” which came into being as the first vertebrates during the Cambrian period 500 million years ago. Our single lens eyes, our jaws, our bilateral brains, our lungs as derivatives of buoyancy bladders, all these features of our own beings came into being through our fish relatives. Some of our oldest relatives are the sharks which evolved about 400 million years ago and who still patrol the oceans with sophisticated sensing, navigational ability, and fast mobility. “A number of huge, and necessarily early, innovations occurred in the sea: the evolution of animals and animal bodies, senses, limbs, nervous systems, and brains. The sea is the natural context of these stages. … We have the marine stages to thank for the nerves and brains through which these words are buzzing, for animal bodies, and for experience itself”.
Humans have existed for at least the last 200,000 years. For most of that time we existed as hunter, gatherers, part of the natural ecosystem. Only relatively recently, in the last few thousand years, have we devised cultural evolution, changed and massively manipulated ecosystems for our own purposes. Since that time, we as humans, through our mythologies, have tended to have the hubris that we are separate from nature, that we are the only conscious and sentient beings on the earth. We tend to dismiss the minds of other creatures and not consider where we came from, that our brains and sense of self are only recent alterations in the long 500-million-year evolution of mindfulness, that we share our heritage, our consciousness, and our sense of self with millions of other creatures. If reading a book like this does anything it will hopefully make you pause when you encounter the many other creatures around you, be they mammals, birds, reptiles, arthropods or fish; be humble and realize that we are only a recent appearance in the miracle of sentient life on this small rock. Preserve and respect all life. JACK