First Life opens with a beautifully evocative anecdote. Taking a night-time swim off the coast of Baja California beneath a clear starry sky, David Deamer was struck by an overpowering sense of oneness with the Universe. Starlight from the bright constellations above had travelled hundreds of light years to mix with the flashing luminescence of aquatic living organisms as he swam in the bay. Could there really exist a link between the stars and life, in a scientific sense rather than astrological?
Deamer certainly thinks so, and in this insightfully written book he explains how over recent decades we have come to understand how the roots of life on Earth reach back out into the cosmos. The chemical elements needed for life - carbon, oxygen, nitrogen and so on - are synthesised deep in the fiery cores of stars, and even many of the fundamental molecular building blocks of cells, such as amino acids, have been discovered inside meteorites.
But the question remains: how do you get from the simple chemical building blocks of life to life itself? How did information-storing, replicating molecules such as DNA first become associated with the intricate reaction network of biochemistry, and both become encapsulated in a membrane bubble - an essential three-way collaboration to build even the simplest cell? We're still a long way off a comprehensive answer to this question, or even a widely supported theory of where on the early Earth and under what set of conditions this biological genesis actually occurred.
Here, Deamer makes a valiant effort to explain the current state of the field and the latest hypotheses, and, drawing on his distinguished research career at the University of California, Santa Cruz, he also charts how these ideas have developed over recent decades and the personalities involved. He is a lipid chemist, interested in how oily hydrocarbon molecules can self-assemble into natural barrier layers and bubbles resembling cell membranes, and naturally this topic is the focus of much of the book.
In the book's penultimate chapter, Deamer describes what he sees as the future of this line of research: a biochemical reactor able to recreate the volcanic environment of the early Earth and so investigate the chemistry of the origins of life on the lab bench. His dream machine is not yet built - it exists only as a thought experiment - but it represents a bold experimental programme to systematically attack this open question.
He envisions a vessel with a controllable internal environment, in terms of the temperature or acidity of the water, complemented with different mineral surfaces that could serve as catalysts to drive chemical reactions, and a suite of high-tech detection equipment to analyse samples taken from the reactor throughout every experimental run. For example, Deamer describes how such a reactor could be seeded with nucleotides to study how readily they can be made to link together into the long-chain molecules RNA and DNA that are needed for life, or doping the sterile circulating fluids within the reactor with simple compounds such as hydrogen cyanide or formaldehyde and incubate them for periods to see what kinds of more complex organic molecules can be cooked up.
This is exactly the experimental programme that we have initiated at University College London, led by Nick Lane, and we have constructed just such a prebiotic reactor to investigate the origins of life.
Deamer puts his money on the origin of life taking place on the flanks of a primordial volcano, periodically wetted with rain or seawater, where cycles of dry heating and desiccation act to drive the building of complex long-chain molecules.
Our group, on the other hand, believes that deep-sea serpentinisation hydrothermal vents, where warm alkaline fluids circulate through fantastically porous chimney walls, present a much more likely crucible for creating the first cells.
Whatever the answer, it is certainly a very exciting time in research into our own origins, and First Life is a masterly introduction to the playing field.
First Life: Discovering the Connections between Stars, Cells, and How Life Began
By David Deamer. University of California Press. 288pp, £19.95. ISBN 97805202583. Published 10 May 2011