Despite a century and a half of research since Darwin, our existence is still a thing of wonder, argues our medical columnist.
By Dr. James Le Fanu
Telegraph.co.uk 09 Feb 2009
“Wonders are there many,” observed the Greek dramatist Sophocles, “but none more wonderful than man.” And rightly so, for we, as far as we can tell, are the sole witnesses of the splendours of the universe β though consistently less impressed by this privileged position than would seem warranted.
The chief reason for that lack of astonishment has always been that the practicalities of our everyday lives are so simple and effortless as to seem unremarkable. We open our eyes on waking to be surrounded by the shapes and colours, sounds and smells of the world in the most exquisite detail. We feel hungry, and by some magical alchemy of which we know nothing, our bodies transform the food and drink before us into our flesh and blood. We open our mouth to speak and the words flow in a ceaseless bubbling brook of thoughts and ideas.
We reproduce, and play no part in the transformation of the fertilised egg into a fully formed embryo with its 4,000 functioning parts. We tend to our children’s needs, but effortlessly they grow to adulthood, replacing along the way virtually every cell in their bodies.
These practicalities are not in the least bit simple, but in reality are the simplest things we know β because they have to be so. If our senses did not accurately capture the world around us, were the growth from childhood not virtually automatic, then “we” would never have happened.
There is, from common experience, nothing more difficult than to make the complex appear simple, just as a concert pianist’s effortless playing is grounded in years of toil and practice β so that semblance of simplicity must reflect the complexities of the processes that underpin them. This should, by rights, be part of general knowledge, a central theme of the school curriculum, promoting that appropriate sense of wonder in young minds at the fact of their very existence.
But one could search a shelf’s worth of biology textbooks in vain for a hint of the extraordinary in their detailed exposition of those complexities of life. Rather, for the past 150 years, scientists have interpreted the world through the prism of supposing there is nothing in principle that cannot be accounted for β where the unknown is merely waiting to be known. At least till very recently, when the findings of two of the most ambitious scientific projects ever conceived have revealed quite unexpectedly β and without anyone really noticing β that we are after all “a wonder” to ourselves.
It started in the early 1980s with a series of technical innovations in genetics and neuroscience that promised to resolve the final obstacles to comprehensive understanding of ourselves. They were, first, the immensely impressive achievement of spelling out the entire sequence of genes strung out along the double helix β the genome β of worms, flies, mice, monkeys and humans, which should have identified those “instructions” that so readily distinguish one form of life from another.
And second, the development of those equally impressive scanning techniques that would permit neuroscientists for the first time to observe the brain “in action”: thinking, imagining, perceiving β all the seemingly effortless features of the human mind.
This was serious science of the best kind, filling learned journals and earning Nobel Prizes while holding out the exhilarating prospect that these most fundamental questions of genetic inheritance and the workings of the human brain might finally be resolved.
The completion of the human genome project, on the cusp of the new millennium, marked “one of the most significant days in history”, as one of its architects described it. “Just as Copernicus changed our understanding of the solar systemβ¦ so knowledge of the human genome would change how we see ourselves.”
At the same time Professor Steven Pinker, of the Massachusetts Institute of Technology, after reviewing how neuroscientists with their new techniques had investigated everything “from mental imagery to moral sense”, confidently anticipated “cracking the mystery of the brain”.
Nearly a decade has passed since those heady days, and looking back, it is possible to see how the findings of both endeavours have enormously deepened our knowledge of life and the mind β but in a way quite contrary to that anticipated.
The genome projects were predicated on the reasonable assumption that spelling out the full complement of genes would clarify, to a greater or lesser extent, the source of that diversity of form that marks out the major categories of life. It was thus disconcerting to learn that virtually the reverse is the case, with a near equivalence of a (modest) 20,000 genes across the vast spectrum from a millimetre-long worm to ourselves.
It was similarly disconcerting to learn that the human genome is virtually interchangeable with that of our fellow vertebrates, such as the mouse and our primate cousins.
“We cannot see in this why we are so different from chimpanzees,” remarked the director of the chimp genome project. “The obvious differences cannot be explained by genetics alone.” This would seem fair comment but leaves unanswered the question of what does account for those distinctive features of standing upright and our prodigiously large brain.
More unexpected still, the same regulatory genes that cause a fly to be a fly, it emerged, cause humans to be humans with not a hint of why the fly should have six legs, a pair of wings and a brain the size of a full stop, and we should have two arms, two legs and a turbo-sized brain. These “instructions” must be there, of course, but we have moved in the wake of these projects from supposing we knew the principles of the genetic basis of the infinite variety of life, to recognising we have no conception of what they might be.
At the same time, neuroscientists observing the brain in action were increasingly perplexed at how it fragments the sights and sounds of every transient moment into a myriad of separate components, with no compensatory mechanism that would reintegrate them together into that personal experience of being at the centre of a coherent, ever-changing world.
Meanwhile, the greatest conundrum remains β how the monotonous electrical activity of those billions of neurons in the brain “translates” into the limitless range and quality of subjective experiences of our lives, where every moment has its own unique, intangible feel.
The implications are clear enough: while theoretically it might be possible for neuroscientists to know everything about the physical structure of the brain, its “product”, the mind, with its thoughts and ideas, impressions and emotions, would still remain unaccounted for.
“We seem as far from understanding the brain as we were a century ago,” says the editor of Nature, John Maddox. “Nobody understands how decisions are made or how imagination is set free.”
There is in all this the impression that triumphant science has stumbled on something of immense importance β a powerful parallel reality that might conjure the richness of the living world from the bare bones of the genes strung out along the double helix and the parallel richness of the mind from the electrochemistry of the brain.
Certainly, for the foreseeable future there will be no need to defer to those who would appropriate our sense of wonder at the glorious panoply of nature and ourselves, by their claims to understand it. Rather, the very aspect of the living world now seems once again infused with that deep sense of mystery of “How can these things be?”
James Le Fanu’s new book, ‘Why Us?: How Science Rediscovered the Mystery of Ourselves’ (HarperCollins), is available from Telegraph Books for Β£16.99 + Β£1.25 p&p