Metazoa by Peter Godfrey-Smith

Reviewed by Patricia Simms-Reeve

Peter Godfrey-Smith is a philosopher scientist who writes with a clarity and beauty of language which make his latest work, Metazoa, easily accessible to the lay person who has a natural curiosity and an appreciation of science, especially biology.

Life on Earth began with minute organisms with an intricate structure on a tiny scale. Over millions of years, more complex structures evolved.  In the 16th century, Descartes, the French-born Philosopher/ Scientist, maintained that life is linked to mind which is separate from the materialist view.  This takes action and sensitivity into account. So the mind can be a natural extension to living activity. Or, conversely, activity by a living form can indicate mind.

In today’s world, the computer demonstrates high level memory and reasoning but is not alive.

Experience may be linked to memory, an important attribute of mind.

Questions are proposed, for example, is a cerebral cortex necessary for experience which is subsequently stored in memory? Some organisms have no cerebral cortex but do they have experience/memory? This leads to a form of consciousness when it can display sentience of, say, pleasure/pain and good/bad. Peter Godfrey-Smith then examines “subjective experience”.

In the Chapter headed “The One Armed Shrimp”, he conveys pure excitement in his discovering this small creature, when its feeler was touched, emerging from hiding and staring at him.

Mountains of information are lightened occasionally with humour, too. He suggests that the difference in size of its two major claws was ‘as if the animal had bought it late online’!  This shrimp, made like a ‘Swiss Army Knife’, in its diverse sections and movement is a giant step from soft corals and sponges – that are alive but not aware.

The next step is sensing. When the shrimp’s feelers respond immediately, this can mean confusion or opportunity.

All this developed 540 million years ago in the Cambrian period.

It is the lengthy chapter on the Octopus that is riveting. All its neurons are not in the brain in its head. The nervous system is decentralised. Two-thirds of its neurons are in the arms.  One experiment demonstrated an octopus using only one arm to reach along, out of water to reach food, then back again. An Octopus may vary in size from a matchbox to a football.

Godfrey-Smith has studied an ‘Octopolis’ in Nelson Bay. It has 18 different sizes living together. They have built a den of scallop shells, which has grown over the ten years. This small society’s members only live 1-2 years, but have learned cooperation. There are many fights but no fatalities.

Many regard the Octopus as ‘smart’, but Peter Godfrey-Smith is hesitant. He concedes they are curious and have individual quirks. It displays consciousness and there is an ongoing debate as to the capability of its split brain. Establishing the autonomy of those eight arms and the degree of operation of the central brain is an aspect of the study of subjectivity.

The powerful big fish, like the Kingfish, can move at speed through thick water. He informs at length about them, and follows with the land creatures, insects, birds and so on.  The scientific detail supported by tests and longitudinal studies is at times, challenging.

Metazoa is a book to be kept at hand and delved into at regular intervals so that its brilliant contents can be fully appreciated and absorbed.

This is merely a snapshot of the contents of Metazoa.

The wealth of knowledge in the book bestows an awe in the complexity and brilliance of the myriad life forms on our planet. It’s another platform, and further reason, to launch strenuous efforts to conserve and protect this world.

Metazoa: Animal Minds and the Birth of Consciousness


by Peter Godfrey-Smith

Harper Collins

ISBN  9 780008 321208

$32.99; 288pp


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