The Ascent of Man (27 page)

The men who made the wild inventions and the grand ones came from the same mould. Think of the invention that rounded out the Industrial Revolution as the canals had begun it: the railways. They were made possible by Richard Trevithick, who was a Cornish
blacksmith and a wrestler and a strong man. He turned the steam engine into a mobile power pack by changing Watt’s beam engine into a high-pressure engine. It was a life-giving act, which opened a blood-stream of communication for the world, and made England the heart of it.

We are still in the middle of the Industrial Revolution; we had better be, for we have many things to put right in it.
But it has made our world richer, smaller, and for the first time ours. And I mean that literally: our world, everybody’s world.

From its earliest beginnings, when it was still dependent on water power, the Industrial Revolution was terribly cruel to those whose lives and livelihood it overturned. Revolutions are – it is their nature, because by definition revolutions move too fast for those
whom they strike. Yet it became in time a social revolution and established that social equality, the equality of rights, above all intellectual equality, on which we depend. Where would a man like me be, where would you be, if we had been born before 1800? We still live in the middle of the Industrial Revolution and find it hard to see its implications, but the future will say of it that in the ascent
of man it is a step, a stride, as powerful as the Renaissance. The Renaissance established the dignity of man. The Industrial Revolution established the unity of nature.

That was done by scientists and romantic poets who saw that the wind and the sea and the stream and the steam and the coal are all created by the heat of the sun, and that heat itself is a form of energy. A good many men thought
of that, but it was established above all by one man, James Prescott Joule of Manchester. He was born in 1818, and from the age of twenty spent his life in the delicate detail of experiments to determine the mechanical equivalent of heat – that is, to establish the exact rate of exchange at which mechanical energy is turned into heat. And since that sounds a very solemn and boring undertaking,
I must tell a funny story about him.

In the summer of 1847, the young William Thomson (later to be the great Lord Kelvin, the panjandrum of British science) was walking – where does a British gentleman walk in the Alps? – from Chamonix to Mont Blanc. And there he met – whom does a British gentleman meet in the Alps? – a British eccentric: James Joule, carrying an enormous thermometer and accompanied
at a little distance by his wife in a carriage. All his life, Joule had wanted to demonstrate that water, when it falls through 778 feet, rises one degree Fahrenheit in temperature. Now on his honeymoon he could decently visit Chamonix (rather as American couples go to Niagara Falls) and let nature run the experiment for him. The waterfall here is ideal. It is not all of 778 feet, but he would
get about half a degree Fahrenheit. As a footnote, I should say that he did not – of course – actually succeed; alas, the waterfall is too broken by spray for the experiment to work.

The story of the British gentlemen at their scientific eccentricities is not irrelevant. It was such men who made nature romantic; the Romantic Movement in poetry came step by step with them. We see it in poets like
Goethe (who was also a scientist) and in musicians like Beethoven. We see it first of all in Wordsworth: the sight of nature as a new quickening of the spirit because the unity in it was immediate to the heart and mind. Wordsworth had come through the Alps in 1790 when he had been drawn to the Continent by the French Revolution. And in 1798 he said, in
Tintern Abbey
, what could not be said better.

For nature then …

To me was all in all – I cannot paint

What then I was. The sounding cataract

Haunted me like a passion.

‘Nature then to me was all in all.’ Joule never said it as well as that. But he did say, ‘The grand agents of nature are indestructible’, and he meant the same things.

The theory of evolution by natural selection was put forward in the 1850s independently by two men. One was Charles Darwin; the other was Alfred Russel Wallace. Both men had some scientific background, of course, but at heart both men were naturalists. Darwin had been a medical student at Edinburgh University for two years, before his father who was a wealthy
doctor proposed that he might become a clergyman and sent him to Cambridge. Wallace, whose parents were poor and who had left school at fourteen, had followed courses at Working Men’s Institutes in London and Leicester as a surveyor’s apprentice and pupil teacher.

The fact is that there are two traditions of explanation that march side by side in the ascent of man. One is the analysis of the
physical structure of the world. The other is the study of the processes of life: their delicacy, their diversity, the wavering cycles from life to death in the individual and in the species. And these traditions do not come together until the theory of evolution; because until then there is a paradox which cannot be resolved, which cannot be begun, about life.

The paradox of the life sciences,
which makes them different in kind from physical science, is in the detail of nature everywhere. We see it about us in the birds, the trees, the grass, the snails, in every
living thing. It is this. The manifestations of life, its expressions, its forms, are so diverse that they must contain a large element of the accidental. And yet the nature of life is so uniform that it must be constrained
by many necessities.

So it is not surprising that biology as we understand it begins with naturalists in the eighteenth and nineteenth centuries: observers of the countryside, bird-watchers, clergymen, doctors, gentlemen of leisure in country houses. I am tempted to call them, simply, ‘gentlemen in Victorian
England’, because it cannot be an accident that the theory of evolution is conceived twice by two men living at the same time in the same culture – the culture of Queen Victoria in England.

Charles Darwin was in his early twenties when the Admiralty was about to send out a survey ship called the
Beagle
to map the coast of South America, and he was offered the unpaid post of naturalist. He owed
the invitation to the professor of botany who had befriended him at Cambridge, though Darwin had not been excited by botany there but by collecting beetles.

I will give a proof of my zeal: one day, on tearing off some old bark, I saw two rare beetles, and seized one in each hand; then I saw a third and new kind, which I could not bear to lose, so that I popped the one which I held in my right
hand into my mouth.

Darwin’s father opposed his going, and the captain of the
Beagle
did not like the shape of his nose, but Darwin’s Wedgwood uncle spoke up for him and he went. The
Beagle
set sail on 27 December 1831.

The five years that he spent on the ship transformed Darwin. He had been a sympathetic, subtle observer of birds, flowers, life in his own countryside; now South America exploded
all that for him into a passion. He came home convinced that species are taken in different directions when they are isolated from one another; species are not immutable. But when he came back he could not think of any mechanism that drove them apart. That was in 1836.

When Darwin did hit on an explanation for the evolution of species two years later, he was most reluctant to publish it. He might
have put it off all his life if a very different kind of man had not also followed almost exactly the same steps of experience and thought that moved Darwin, and arrived at the same theory. He is the forgotten and yet the vital character, a sort of man from Porlock in reverse, in the theory of evolution by natural selection.

His name was Alfred Russel Wallace, a giant of a man with a Dickensian
family history as comic as Darwin’s was stuffy. At that time, in 1836, Wallace was a boy in his teens; he was born in 1823, and that makes him fourteen years younger than Darwin. Wallace’s life was not easy even then.

Had my father been a moderately rich man … my whole life would have been differently shaped, and though
I should, no doubt, have given some attention to science, it seems very unlikely
that I should have ever undertaken … a journey to the almost unknown forests of the Amazon in order to observe nature and make a living by collecting.

So Wallace wrote about his early life, when he had had to find a way to earn his living in the English provinces. He took up the profession of land-surveying, which did not require a university education, and which his older brother could teach
him. His brother died in 1846 from a chill he caught travelling home in an open third-class carriage from a meeting of a Royal Commission committee on rival railway firms.

Evidently it was an open-air life, and Wallace became interested in plants and insects. When he was working at Leicester, he met a man with the same interests who was rather better educated. His new friend astonished Wallace
by telling him that he had collected several hundred different species of beetles in the neighbourhood of Leicester, and that there were more to be discovered.

If I had been asked before how many different kinds of beetles were to be found in any small district near a town, I should probably have guessed fifty … I now learnt … that there were probably a thousand different kinds within ten miles.

It was a revelation to Wallace, and it shaped his life and his friend’s. The friend was Henry Bates, who later did famous work on mimicry among insects.

Meanwhile the young man had to make a living. Fortunately, it was a good time for a land-surveyor, because the railway adventurers of the 1840s needed him. Wallace was employed to survey a possible route for a line in the Neath Valley in South
Wales. He was a conscientious technician, as his brother had been and as Victorians were. But he suspected rightly that he was a pawn in a power game. Most of the surveys were only meant to establish a claim against some other railway robber baron. Wallace calculated that only a tenth of the lines surveyed that year were ever built.

The Welsh countryside was a delight to the Sunday naturalist,
as happy in his science as a Sunday painter is in his art. Now Wallace observed and collected for himself, with a growing excitement in the variety of nature that affectionately remained in his memory all his life.

Even when we were busy I had Sundays perfectly free, and used then to take long walks over the mountains with my collecting box, which I brought home full of treasures … At such times
I experienced the joy which every discovery of a new form of life gives to the lover of nature, almost equal to those raptures which I afterwards felt at every capture of new butterflies on the Amazon.

Wallace found a cave on one of his weekends where the river ran underground, and decided then and there to camp overnight. It was as if unconsciously he was already preparing himself for life in
the wild.

We wanted for once to try sleeping out-of-doors, with no shelter or bed but what nature provided … I think we had determined purposely to make no preparation, but to camp out just as if we had come accidentally to the place in an unknown country, and had been compelled to sleep there.

In fact he hardly slept at all.

When he was twenty-five, Wallace decided to become a full-time naturalist.
It was an odd Victorian profession. It meant that he would have to keep himself by collecting specimens in foreign parts to sell to museums and collectors in England. And Bates would come with him. So the two of them set off in 1848 with £100 between them. They sailed to South America, and then a thousand miles up the Amazon to the city of Manaus, where the Amazon is joined by the Rio Negro.

Wallace had hardly been further than Wales, but he was not overawed by the exotic. From the moment of arrival, his comments were firm and self-assured. For example, on the subject of vultures, he records his thoughts in his
Narrative of Travels on the Amazon and Rio Negro
five years later.