Michael Marshall, "The Genesis Quest" (2020)

 I really enjoyed Michael Marshall's The Genesis Quest (full title: The Genesis Quest: the Geniuses and Eccentrics on a Journey to Uncover the Origin of Life on Earth), which is recently out in paperback.

Usually I read books quickly, but this one took me a time, because each chapter is so full of toothsome detail: an expert's guided tour through the many and various scientists who have tried to answer the fundamental question, how did life arise on Earth? It's a question that entails a deeper one, ‘what is life, exactly?’ which Marshall does not shirk. The whole is written with wonderful clarity, occasional moments (especially in the footnotes) of nimble wit, and above all without cutting corners or skimming past any of its rich and fascinating narrative. I know a great deal more about crystals, cells, membranes, RNA, DNA and many other things now than I did before I read this.

Reading made me realise how far it is possible to know a vast amount about the various biochemical and other aspects of ‘life’—and we know more now than at any time before in human history—without that automatically leading to a situation in which we are able to frame ‘answers’, let along ‘an answer’, to the fundamental question posed. Many solutions have been proposed, but there isn't one that garners widespread scientific support, let alone which solves or provides consensus. Remarkable, really.

So, yes, we still don't really know how life came about. It seems the debate is split between those who think that life began with self-replicating proteins is some primordeal soup (it has been shown, by Sidney Walter Fox and others, that amino acids can spontaneously form complex proteins and perhaps even can aggregate into sort-of protocells), and those who believe that membranes are key, since all this amino acid action and metamorphosis will tend to fall apart again without a container of some kind to keep it all in. The ‘membrane-first’ school includes people like David Deamer, William Hargreaves, and Pier Luigi Luisi (Marshall works, creditably, to include as many female scientists as possible in his account, although his narrative is still pretty bloke-heavy). A third theory puts the emphasis on energy, a constant input of which is needful (say some) to counter the entropy that would otherwise collapse the possibilities of complex life as an onward growing phenomenon. Marshall relates the excitement at the discovery of those lifeforms that have evolved around alkaline deep-sea hydrothermal vents, far from the sun, which some think provide the source for all life, though Marshall remains unconvinced by this line.

But though all three theories have supporters, there is no general agreement on which one is closest to the truth. Marshall himself seems to incline towards the ‘chemoton’ model, first proposed by Hungarian scientist Tibor Gánti (though it was, it seems, initially greeted with ‘lack of interest, incomprehension, ridicule and malevolence’ in Gánti's homeland):

The underlying thought behind the chemoton model is that genes on their own, a metabolism on its own, or a membrane on its own cannot achieve very much. The essence of life is the interaction of all three. While most researchers interested in the origin of life were dividing life up into its subsystems, in the hope one of them might be enough to get life started, Gánti instead tried to imagine the simplest possible organism that had all three. [250]

Marshall is too scrupulous a scientist to thump the tub for any one theory, when the science is so contested, but this ‘everything at once’ theory is the one towards which his book leans.

 One thing that I got from this slow, detailed account of the many theories of life's origins was a sense of deep time. Say we started (as most scientists agree we did) with something simple: life as it has now evolved is dazzlingly complex, and that, chemoton model or no chemoton model, is not something that happened overnight. The great gulfs of the past are overgrown with the gradually complexifying forms of this stuff, this thing, this life. That in turn made me reflect on something Marshall does not discuss, since it's not part of his brief: consciousness—specifically, the startling recent-ness of self-aware, self-reflexive minds. For most of that huge backward and abysm of Earth's historical past nothing has both observed and reflected upon the fact there was anything worth observing and reflecting upon. That's a development in life that happened, like, five minutes ago, basically. Nor will it last: ‘before too many billions of years have passed, matter will be too spread to ever condense into new stars ... on this view, we exist in a special period in the universe's history: the one short epoch where isolated pockets of life can emerge, before everything becomes fundamentally uninteresting’ [291] Woh! Marshall adds, with a characteristic touch:

There's a curiously profound line of dialogue in Avengers: Age of Ultron, a film that's otherwise a bit of a mess. The android character Vision is told that the human race is destined to become extinct. He replies: “yes. But a thing isn't beautiful because it lasts.”

“Eternity is in love with the productions of time” as William Blake noted, a piece of profundity that takes its place in a larger body of work determinately not a bit of a mess. Marshall doesn't quote Blake, but he's right about this line from Age of Ultron. And his whole book is precisely as curious and profound as the wisdom he identifies here. Very highly recommended.