Evolution’s destiny

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Robert Williams and Ros Rickaby
RSC Publishing
August 2012 | 366pp | £69.99 (HB)
ISBN 9781849735582

First there was inorganic chemistry (the solar system, the elements and minerals – about 4 to 5 billion years ago, 4–5Ga). Then there was life, the crucial role of photochemistry, emergence of cells, of DNA, blue-green algae (circa 2Ga) and the production of oxygen, followed by animals (circa 1Ga).

In this scholarly, thought-provoking book, the authors (a bioinorganic chemist and a biogeochemist) explore the role of chemistry in evolution, and in particular the changing role of inorganic elements in the evolution of the ecosystem. They emphasise that inorganic and organic chemistry are interactive and not separate. The waste products of cellular organic chemistry can initiate major changes in environmental inorganic chemistry.

This is certainly a book that can be used to train and challenge young (and old!)minds in interdisciplinary thinking. In chapter 1, there are relevant chemical principles, including complex ion equilibria, redox potentials, kinetics and catalysis. Chapter 2 deals with the formation of the Earth, isotope studies, the early development of the environment (<3Ga) and later emergence of oxidation (for example of iron and sulfur), and trace elements in the sea. In chapter 3, the evolution of organic chemistry of organisms is linked to geological inorganic chemistry using fossil evidence – for example, the beautiful mineralised architectures of cockle shells (calcium carbonate) and amoeboid protozoa (silica).

Chapter 4 is an overview of the organic chemistry of living cells, with emphasis on its emergence from environmental inorganic chemicals such as water, carbon dioxide, nitrogen, phosphate and sulfate. The important topics of spatial compartmentalisation in cells and multicellular organisms, and control of growth and shape are considered. The rejection of sodium and chlorine from cells and more generally elemental speciation in cells is the focus of chapter 5 – including the central role of calcium ions in signalling, of sodium and potassium ions in neurotransmission and formation of biominerals.

There is much stimulating material in chapter 7 – an amalgamation of chemical and genetic approaches to evolution: ‘The human DNA sequence does not relate to humans as an organism because this organism depends on the cells’ mitochondrial DNA and all the DNAs of the essential symbiotic “organisms” living within the human body or outside it.’ The assertion that ‘some of the underlying ideas in Gaia may be incorrect’ has the ring of a student exam question! Indeed we should persuade all undergraduates to read this book to help develop their questioning minds, challenge thinking, and realise that essay construction based on logical thought has a firm place, even in chemistry.

How did we get here? Where are we going? Perhaps only chemists will be able to grasp the bigger picture: ‘Man’s activity is now one major driving force on the whole of life’s evolution…. It is a total system that evolves, including the environment and organisms.’ Do you agree?

Purchase this book from the RSC bookshop. RSC members are eligible for a 35% discount.