The Genesis Quest – The Geniuses and Eccentrics on a Journey to Uncover the Origin of Life on Earth
Michael Marshall, Weidenfeld and Nicholson, 360 pages
All societies have their own creation myths which describe the origin of the cosmos and of life itself.
In spite of these myths, the big question remains: just how did life originate? Not an easy question to answer.
The thing about life is that is a very complex phenomenon and biologists are still not unanimous about a common definition or description. As is often the case in biology (and medicine), concepts are frequently a bit fuzzy around the edges.
Marshall does not really elaborate about this but I do not think that it detracts from the book – in fact this is one of the best popular books on this subject that I have read for some time.
Origin research, not as glamorous as the often-overhyped breakthroughs in, say, cosmology or medicine, always had to make do with the few financial crumbs left over after the other subjects have emptied the purse.
Marshall begins his history in the 1920’s, with Alexander Oparin and JBS Haldane’s concept of the origin of life in the primordial soup. Both were communists and he speculates that their viewpoints, rooted as they were in materialism, were influenced by this political philosophy. Be that as it may, life could not have originated by any process other than the probiotic interaction of chemicals.
In 1953 Stanley Miller discovered that amino acids, an essential building block of proteins, could form under natural conditions. He was only 22 at the time and nothing in the rest of his long career equaled this youthful accomplishment.
Miller’s assumptions about the prevailing conditions in the primeval atmosphere are now known to be false and were severely criticized. In spite of this it inspired many new ideas, hypotheses and experiments, fertilizing discussions during the 1970’s and 80’s about which of life’s basic functions came first, where it occurred and the nature of the first organisms.
Marshall discusses the four major theories addressing this: proteins first, compartmentalization first (being separate from the environment), RNA first (the RNA world) and metabolism first. Discovery of undersea waterspouts seemed to support the metabolism first theory to some extent and is supported by some major figures in the field.
This of course raises the question: where exactly did life originate – in the sea, suboceanic waterspouts, or small pools alternately dried out and watered by rainfall.
The latter scenario inevitably reminded me of Charles Darwin’s 1871 letter to Joseph Hooker: “But if (and oh what a big if) we could conceive in some warm little pond with all sorts of ammonia and phosphoric salts, light, heat, electricity etcetera present, that a protein compound was chemically formed, ready to undergo still more complex changes…”
On page 215 we read: “Astute readers may sense a ‘but’ coming, and it is a big one. Go back over the chapter so far and count the number of times you see the word ‘experiment’. There won’t be many… The whole elaborate edifice has very little experimental evidence behind it.”
Every theory mentioned above contributed important insights about the origin of life, insights which expanded when scientists realized that energy, in the form adenosine triphosphate (ATP) or a precursor, must have been of cardinal importance in the origin of life and its organization.
In the last part of the book, “Reunification,” Marshall gives a good resume of the present state of affairs. No single concept, theory or process can adequately describe something as complex as life – to do that we need an ensemble of metabolism, genes, and a membrane bound cell.
Jack Szostak is a Nobel laureate who has done remarkable and charming experiments with ribonucleic acid, succeeding in establishing a model system where genes copy themselves inside a membrane-bound cell, although so far they have not shown any signs of metabolism.
The boundary between life and non-life seems to be fading. “In truth, the question is arguably meaningless. The first life was so intimately bound up with its surroundings that it is difficult to tell what should count as organism and what as surroundings. If chemical reactions in a pool make a protein, but this happens a millimetre away from the nearest DNA, which label should we use? We can only decide which parts of the pool are alive and which aren’t, and in the absence of a lipid membrane to define a cell, there is no good criterion.”
Bottom line: no, we don’t know. I doubt that we will attain that knowledge even in my granddaughter’s lifetime.
The book is well written and readers do not need previous knowledge of biology or biochemistry. A few illustrations would not be amiss, though.
Those who want to find out more about this fascinating subject are invited to watch this video.
The views and opinions expressed in this article are those of the author, and do not necessarily reflect the position of this publication.
