The God of Small Things
J. B. S. Haldane’s famous quip about God’s apparent “inordinate fondness for beetles” needs updating. What current biology teaches is that if God (I use the term in the Einsteinian sense) had nominated a class of creatures to do His work on earth it would have been the bacteria and their cousins the Archaea.
This insight is yet to become public knowledge because we are creatures who can see nothing smaller than one tenth of a millimetre with the unaided eye (and that an undifferentiated dot). Bacteria — which contain churning complex chemical processing facilities and around 1500 genes — are from 20 to 200 times smaller. They are what my late co-author the sculptor Tom Grimsey called Giants of the Infinitesimal and the great physicist Richard Feynman famously typed as the “bottom” which nevertheless contained “plenty of room”.
Although a physicist, Feynman knew that nature was the master of nanoscience:
“It is very easy to answer many….fundamental biological questions; you just look at the thing! You will see the order of bases in the chain; you will see the structure of the microsome. Unfortunately, the present microscope sees at a scale which is just a bit too crude. Make the microscope one hundred times more powerful, and many problems of biology would be made very much easier.”
Grasping the nature and importance of the nanoworld was easy for Richard Feynman but difficult for most of us. We evolved to make sense of the world on the basis of the senses we possess. This was adequate for thousands of years and even led to many technological marvels that succeeded despite a total lack of scientific underpinning.
But science now at its most powerful and profound deals with minute organisms and even smaller chemical entities that the eye cannot see and the untutored imagination cannot conceive and therefore deems unimportant. The unscientific think that “seeing is believing”; scientists know that seeing at the resolution of the human eye is of little use. Those tiny bacteria contain intricate chemical nanomachines that can achieve things that are still way beyond human technology: creating biomass from light, water and carbon dioxide, for instance — the holy grail of energy researchers. Every leaf can do that but bacteria invented it.
For those who know something of the chemical basis of life, recent knowledge has administered a shock to human vanity. It transpires that, as far as the planet is concerned, we are a minor inessential excrescence. For it is microbes that have been running the earth’s ecosystems for around 4 billion years. In a mere twinkling of time at the end of this period, an upstart multicellular creature that styled itself Homo sapiens developed the delusion that it was master of the planet. For a while the two realms of life coexisted in ignorance of each other — the pretensions of the would-be usurper were harmless to the microbes, which continued to maintain the atmosphere at 21 % oxygen, the nitrogen cycle that delivered that vital element into the food chain, and all the other delicately balanced mechanisms. The self-styled masters of the planet took these stable conditions for granted and misunderstood the role of the bacteria, regarding them merely as a malign, renegade part of nature whose only purpose was to parasitize and kill humans and which, must consequently be eliminated from the earth.
Then, as knowledge of bacteria’s role as regulator of the ecosystem grew, it became apparent to the humans that their activities had begun to severely upset that regulatory balance set by bacteria. The oxygen content of the atmosphere is slowly falling thanks to our combustive activities which the bacteria cannot keep up with and the natural carbon and nitrogen cycles are way out of kilter.
To maintain the conditions needed to ensure our own survival we will have to start adjusting the parameters formerly set automatically by bacteria. But where to start? If one part of the ecosystem is obviously out of balance, it won’t be enough to address only that part: push down one parameter and others would start to change right across the system. But humans only possess spanners to throw in the works; they don’t have the microbes’ shape-shifting metabolic virtuosity. It turns out that, to turn a modulation on Orwell, in ecological terms: “Once cell is good; many cells bad”.
The bacteria had coped with total reversals of the ecosystem several times in the past: when they started to tap the sun to evolve oxygen, that gas was at first toxic to them but they survived to usher in the oxygen-rich world that sustains us and the other animals. We don’t possess the wisdom of the microbes but we will have to find an equivalent or preside for a little while longer over a world in which only the microbes will have a future.
There is now an overriding imperative for everyone to have some understanding of the great bacterial nanosystems. In the Preface to the 1802 edition of the Lyrical Ballads, Wordsworth wrote: “If the time should ever come when what is now called science, thus familiarized to men, shall be ready to put on, as it were, a form of flesh and blood, the Poet will lend his divine spirit to aid the transfiguration, and will welcome the Being thus produced, as a dear and genuine inmate of the household of man.” This plea for an extended household of man enjoins us to begin to develop an imaginative feel for a world we cannot see without very powerful microscopes. It is possible for the mind to grasp the great skein of biochemical transformations without ever looking down a microscope. Science is a triumph of thought and conceptual imagination as much as it is a work of experiment. The nanoworld — comprising the nanomachines that drive the planet — is the territory we must bring into that Wordworthian household of man. Unless we do, the house is ruined.