Arrival of the Fittest
Greg Spearritt reviews Andreas Wagner’s Arrival of the Fittest (OneWorld Publications, 2015).
How did the incredible eye of that bird of prey, able to see a mouse from a hundred metres above the earth, come about? How did the blind process of evolution throw up exactly the right combination of amino acids and proteins to produce such a wonderful lens?
That, in essence, is the question Arrival of the Fittest considers. As Wagner says:
…no matter how large or small, from the ten feet of a blue whale’s tail fluke to the ten microns of a bacterium’s flagellum, every single one exists because, at some point since life’s origin, the right variation occurred.
That variation is an innovation, a new combination thrown up by slight errors in the copying of DNA. Evolution, in other words: descent with modification. How on earth does this process manage to find the right needle in such an enormous haystack?
Wagner likens genotypes (an organism’s complete set of genes) and phenotypes (the organism’s observable physical traits) to texts in a library. The possible genotypes and phenotypes, some which would support a viable organism and many others which wouldn’t, are unimaginably huge in number. Those which could represent a viable creature are the books in the library that ‘make sense’ and have a meaning. These are scattered among a gigantic number of meaningless texts full of gibberish. How did the bird of prey manage to hit upon the one meaningful text for a viable, incredibly functional eye, made up as it is of one among billions of possible combinations of amino acids? Surely that couldn’t happen by chance?
For context, proteins in the eye such as opsins and crystallins are composed of over 100 amino acid strings. The possible combination of these strings is more than 10130, greater than the number of hydrogen atoms in the universe.
I shall resist the temptation to reveal the spoiler. Suffice it to say, it’s not as impossible as it seems. Life is robust, and the innovation that has led to the bewildering array of species on earth is far more achievable that it first appears. Wagner, through building on the work of others but also through his own experimental projects, demonstrates this fact and communicates it with aplomb.
For those who cling to a ‘God of the gaps’ it’s another in the long line of God-diminishing scientific achievements: in keeping with the pattern over the last couple of hundred years, the natural world requires the explanatory power of a Creator less and less with each new discovery. For those with a more sophisticated theism, as well as for the atheists and agnostics among us, this book will only increase their sense of how marvellous the world is.
Arrival of the Fittest harbours much detail, some of it intellectually challenging, at least for this reviewer, some of it amusing (learn, for instance, how to create mice using wheat, dirty underwear and a plastic bag), but all of it illuminating. The description of how a cell works, for example, is awe-inspiring. In solving a puzzle that Darwin in his day had no chance of sorting out, Wagner underlines the propensity of not just life, but even ‘dead’ matter in the universe, to self-organise – witness the birth of stars and planets from clouds of dust. It’s a gob-smacking universe we live in.
I need to conclude this review before I run out of superlatives. Whether scientifically literate or not, you deserve to have this book on your shelves just to reinforce how bloody wonderful it is to be alive.
Disclaimer: views represented in SOFiA articles are entirely the view of the respective authors and in no way represent an official SOFiA position. They are intended to stimulate thought, rather than present a final word on any topic.