Life on Earth

Here’s my latest review, as published in the Wall Street Journal (apart from small editorial changes their end!)

 

Creation
Adam Rutherford
Penguin

I was slightly taken aback by the title of Adam Rutherford’s book.  He is a respected, and respectable, science writer with the journal Nature; surely he couldn’t be espousing Young Earth Creationism?  But no.  The title of Chapter One, “Begotten, Not Created”, is much more reassuring, and much truer to the theme of the book.  In fact, there are two themes.  In the first part of the book, he discusses the origin of life on Earth, while in the second part he looks to the future in the light of the possibilities opened up by human interference in the processes of life.  As he puts it, “the great theories of biology are now being tested with groundbreaking experimentation”.
     The familiarity of the first part of the story to anyone with an interest in the story of life on Earth might have made it tedious in the hands of a less expert storyteller; but Mr Rutherford is a skilled expositor who is a joy to read and who sheds new light on familiar tales.  The main point of the first part of his book is certainly one that cannot over-emphasised or repeated too often.  All life is made of cells.  All cells operate on the same principles, based on the same genetic code incorporated into DNA.  There is overwhelming evidence that all cells on Earth — meaning all life on Earth — descends from a single ancestor, perhaps not the first cell, but the only one to leave descendants around today.  Indeed, life on Earth may have arisen only once, in the equivalent of what Charles Darwin called a “warm little pond”, way back when our planet was young.  This Last Universal Common Ancestor, or Luca, was around some four billion years ago — or four million millennia ago, as the author puts it.
     In telling the story of Luca, Mr Rutherford covers the history of the cell idea from the pioneering studies of Isaac Newton’s contemporary Robert Hooke right up to date, via the discovery of the nature of DNA and the cracking of the genetic code.  Her then goes back to the beginning, to offer a smorgasbord of theories concerning the origin of the first cell, conjuring up graphic images of the primordial Earth bombarded from space with comets carrying many of the chemical precursors to life, and of volcanic vents deep beneath the surface of the oceans where heat energy can stimulate chemical reactions.  And always behind the story lies the knowledge that although the probability of a single living cell emerging may be small, it only had to happen once.
     Cells, it also turns out, are very easy to make (although living cells may be harder).  The molecules that make up the balloon-like skin of a cell have a head and tail structure, like a miniature tadpole.  If the head “likes” water and the tail “hates” water, as collection of these molecules floating in water naturally curl themselves up into tiny bubbles with their tail pointing inwards.  And many experiments have now shown that other kinds of molecules that would have been around in the oceans of the young Earth do naturally form more complex compounds, on the edge of life, if there is an energy supply.
     The last step, from non-life to life itself, has not yet been completed in the laboratory.  But just about everything else in the way of tinkering with life has, and this is the theme of the second part of the book.
     “If the biological twentieth century was concerned with taking cells apart to understand how they work,” writes Mr Rutherford, the twentyfirst century has “given us the ability to put them back together again” in new designs for specific purposes.  His examples range from a goat whose milk contains strands of silk which can be extracted and spun into thread, potentially offering a way to produce “natural” material to repair damaged ligaments or to make puncture-proof tyres, to the “Minimal Genome Project”, an effort to make the simplest possible living cell.  He makes a fascinating, and clear, comparison between the workings of a cell and the way a computer is programmed and controlled using logic gates, and draws an analogy between genetic  engineering, cutting and pasting stretches of DNA, and word processing, cutting and pasting stretches of text.  One breathtaking achievement (still far from being used in laboratory animals, let alone humans) is the development of a “terminator” virus that can enter a living cell, determine if the cell is cancerous, and if so kill it.  If not, the cell is not interfered with.
     But for me the highlight of the book comes near the end, where Mr Rutherford takes an informed stand against the unthinking opponents of genetic engineering, and especially of genetically modified (GM) foods.  His arguments are clear and compelling, but not to be briefly summarised.  I cannot resist, though, repeating one of his comments.  The British newspaper the Daily Mail, he notes, once ran a headline saying “Scientist accused of playing God after creating artificial life by making designer microbe from scratch — but could it wipe out humanity?”  “The very straightforward answer,” says Mr Rutherford, “is no, as is inevitably the case when newspaper science headlines end with a question mark.”  To find out why, read the book.  And bear the aphorism in mind when reading newspapers!
     So why call the book Creation?  Because “in the next few years, for only the second time in four billion years, a living thing, probably something akin to a cell, will be born in the laboratory without coming from an existing cell”.  We are the creators.

John Gribbin is a Visiting Fellow in Astronomy at the University of Sussex, and author of Planet Earth (Oneworld)

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