AUTHOR: CHARLES DARWIN
DATE: 1859
Every now and again, a scientific work comes along that not only increases humankind’s collective knowledge but also prompts a step-change in how we as a species view ourselves and our place in the world. In the nineteenth century, it was On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life (to give it its full name) – Darwin’s treatise on the subject of evolutionary biology.
Darwin compellingly argued that species evolve down through generations, changing and adapting in order to secure the greatest chance of ongoing survival. In short, those which evolve to deal with the conditions of life prevail, and those that don’t, die off – a process of natural selection. It is this fundamental idea, he showed, that is responsible for the rich diversity of life that inhabits our planet. For humans, this raised some serious questions, particularly in an age of widespread faith in long-held church teachings. Specifically, much Christian theology held that humans are a species apart from the animals, designed in all their complexity by a creator-God. Darwin, though, now seemed to be saying that the story is a little more complex than that.
By the time of publication, Darwin had been honing his thesis for many years. He was building on the kernel of ideas introduced by other scientists over the previous century. In the eighteenth century, Georges Buffon was conjuring with the idea of species varieties deriving from a common ancestor. Darwin’s own grandfather, Erasmus Darwin, and the naturalist Jean-Baptiste Lamarck had also discussed the transmutation of species over generations. Darwin was also influenced by Thomas Malthus’s theories on human population growth, which chimed with his ideas on the competitive nature of survival.
Darwin had initially studied medicine but soon found his true passion was the natural sciences. In the 1830s, he spent almost five years travelling around the world aboard HMS Beagle, during which time he gathered the notes and data that were to underpin On the Origin of Species. In 1839, Darwin’s journal from these travels was published (becoming popularly known as The Voyage of the Beagle), and making Darwin something of a celebrity in Victorian society.
CHALLENGING ORTHODOXY
The fundamental social and religious implications of Darwin’s work were famously explored in the so-called Scopes Monkey Trial, conducted in Dayton, Tennessee, in 1925. On trial was high school teacher, John Scopes, accused of violating state law by teaching human evolution. He was initially convicted but the verdict was later overturned on a technicality. Scopes, though, had implicated himself in order to bring attention to the tension that existed between those in the Presbyterian Church who believed that religious teaching should respond to the expansion of scientific knowledge and those who believed that the words of the Bible should always take precedence.
The voyage had left him suspecting that species were not fixed, but rather subject to adaptation. But finding himself a man in high demand, it was only in 1842 that he wrote a first brief abstract of his developing theory – notes that comprised some thirty-five pages. Over the next couple of years, he expanded this into an essay over two hundred pages in length. Around the same time, a book by Robert Chambers popularized the idea of species transmutation. Although it was altogether a much less wide-ranging theory than Darwin would eventually launch onto the world, it eased the path for what was to come.
Meanwhile, Darwin was intent on gathering more data. For example, over a period of several years he studied barnacles to detect indicators of their evolution, becoming a world authority on the species. In a similar vein, he turned himself into an expert pigeon breeder. By the mid-1850s, he was fully dedicated to progressing his theory of natural selection as a driver of evolutionary divergence. But there was now another player on the field – naturalist Alfred Russel Wallace was developing his own thesis on the subject.
The two men corresponded and, by 1858, it was apparent that they were heading in similar, if not identical, directions. Spooked that he might be beaten to the punch and that his years of work would be for nothing, Darwin agreed to co-publish and present a collection of papers with Wallace in London. Few outside the specialized scientific community took much notice, though. Darwin now devoted himself to completing On the Origin of Species, which appeared the following year with this startling summation of natural selection:
As many more individuals of each species are born than can possibly survive; and as, consequently, there is a frequently recurring struggle for existence, it follows that any being, if it vary however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selected. From the strong principle of inheritance, any selected variety will tend to propagate its new and modified form.
This was truly revolutionary stuff. Not least, if nature evolves to survive and flourish, where does that leave the idea of a godhead pulling the strings? For the time being, Darwin was careful not to overreach himself. He did not extend his theory to the human species, although he did give a tantalizing glimpse of what it all might mean for us with a line in the last chapter: ‘Light will be thrown on the origin of Man and his history.’ He also noted: ‘There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.’ From the second edition of the book, he added the words ‘by the Creator’ after ‘breathed’.
Fearful of ‘only add[ing] to the prejudices against my views’, it was not until 1871 that Darwin publicly tackled human evolution in The Descent of Man, and Selection in Relation to Sex. By then, the theory of Darwinian evolution had widespread acceptance. Of course, not everyone was convinced. John Herschel, a scientist venerated by Darwin, dismissed the theory as the ‘law of higgledy-piggledy’. Others, more damagingly, abused Darwin’s work for their own ends – in particular, advocates of ‘social Darwinism’ who espoused ideas of ‘survival of the fittest’ to justify theories of racial superiority and eugenics. But away from the hands of the cranks, Darwin’s theory of evolution has proved extraordinarily durable, underpinning over a century and a half of natural science and spilling into other areas as diverse as agriculture, medicine and computer science.