Charles Darwin: gentleman naturalist
A biographical sketch by John van Wyhe
CHARLES Robert Darwin (1809-1882) was born the fifth of six children into a wealthy Shropshire gentry family in the small market town of Shrewsbury. His father, the hugely portly Robert Waring Darwin (1766-1848), was a successful physician and fincancier and son of the famous poet, Erasmus Darwin. Charles Darwin's mother, Susannah Wedgwood (1765-1817), died when he was eight years old. Darwin, watched over by his elder sisters and maidservants, grew up amidst wealth, comfort and country sports. He attended the nearby Shrewsbury School as a boarder from 1818-1825.
In October 1825 Darwin went to Edinburgh University with his brother Erasmus to study medicine with a view to becoming a physician. While in Edinburgh Darwin investigated marine invertebrates with the guidance of Robert Grant. Darwin's name first appeared in print in one of Grant's articles. Darwin did not like the study of medicine and could not bear the sight of blood or suffering and so his father proposed the church as a respectable alternative. The advantage to becoming a country parson, as Darwin saw it, would be the freedom to pursue his growing interest in natural history. He read several books on Christianity while making up his mind. Some of these survive here. To become ordained in the Church of England he must first obtain a B. A. degree from an English university.
On 15 October 1827 he was admitted a member of Christ's College, Cambridge. However, as he had forgotten most of the Greek he had learned at school, and advanced Greek was required in the daily college lectures, Darwin could not come up in October. He studied under a private tutor at home until he was able to translate Greek with some ease. Therefore he did not come into residence in Cambridge until 26 January 1828. As all of the College rooms were full, Darwin first lived in lodgings for Christ's students above W. Bacon, the tobbacconist, on Sidney Street just down the street. (The original building was destroyed in the 1930s but two plaques on the site of a branch of Boot's the chemist mark the location today.) He matriculated, that is signed the role as a member of the University, at the Senate House on 26 February 1828 (not in January as maintained by some biographies). Darwin's student bills were recently discovered at Christ's College and shed new light on his time in Cambridge.
Darwin's cousin, William Darwin Fox, was at Christ's just before Darwin and overlapped with him for a short time. See Fox's diary and accounts recording his early time at Christ's here: Image (Reproduced with permission of Gerry Crombie. Photographed by Colin Higgins.)
Darwin was never a model student, but he did become a passionate amateur naturalist. He began avidly collecting beetles along with fellow undergraduates. His name appeared in print when some of his records of insect captures were published by Stephens in his British Entomology in 1829. Darwin's first published word was "Cambridge". Darwin became the devoted follower of Professor of botany John Stevens Henslow (1796-1861). Through their close friendship Darwin learned a great deal about the practice of natural science. Darwin passed his B.A. examination in January 1831. As he had not fulfilled the residence requirement to take a degree, it was not awarded until 26 April 1831. Shortly thereafter he was taught the rudiments of field geology by Professor Adam Sedgwick during a tour of north Wales.
Henslow was able to pass on to Darwin the offer of Commander Robert FitzRoy of travelling on a survey ship, HMS Beagle, as a "scientific person" or naturalist. The round-the-world journey lasted five years. Darwin spent most of these years investigating the geology and zoology of the lands he visited, especially South America, the Galapagos islands, and Pacific oceanic islands. A section of his massive geological diary is transcribed here. He recorded many of his specimens and observations immediately in field notebooks. His telegraphic pocket notes were later used in writing up more formal notes, such as his animal notes. Later he recorded his experiences in a diary which became the basis of his famous book Journal of researches (1839) now known as Voyage of the Beagle. (This latter title was first used on the title page of a 1905 edition.)
Darwin was particularly influenced by the works of men of science like astronomer Sir John Herschel, traveller Alexander von Humboldt and geologist Charles Lyell. Lyell's new book, Principles of Geology (1830-3), profoundly influenced Darwin. Lyell offered not just a new geology but a new way of understanding nature. Lyell showed how tiny, slow, gradual and cumulative change over immense periods of time could produce large changes. Natural, visible, non-miraculous causes should be sought to explain natural phenomenon. Darwin had the opportunity to witness all of these forces, such as erosion, earthquakes and volcanoes, during the Beagle voyage and he became convinced that Lyell's views were correct. Darwin made several very important discoveries about the geology of South America, volcanic islands and the origins of coral reefs by building on Lyell's ideas. Darwin later wrote in the 2nd edition of his Journal of researches:
Where on the face of the earth can we find a spot, on which close investigation will not discover signs of that endless cycle of change, to which this earth has been, is, and will be subjected?
Darwin also collected organisms of all sorts which he recorded in his specimen lists and zoology notes. These formed the basis of the five volume series he edited and superintended after returning home The zoology of the voyage of H.M.S. Beagle (1838-43).
Geological sections from Darwin's Geological observations on South America.
Darwin also unearthed many fossil creatures in South America. He wondered why the fossils resembled the present inhabitants of that continent more than any other species. Where had the new species come from? In fact, why was the world covered with so many different kinds of living things? Why were some very similar to one another and others vastly different? If species were somehow created to fit their environments, as was then believed, why were jungle species different in Asia, Africa and South America despite the similarity of climate?
Darwin did not conceive of a solution during the Beagle voyage, but rather a few years later in London, while writing books on his travels and studying the specimens he had collected. Experts in London, such as the ornithologist John Gould, were able to tell him how many of the specimens of plants and animals he had collected in the Galapagos Islands were unique species, found nowhere else. Clearly they resembled species from South America 600 miles away. It seemed to Darwin as if stray migrants from South America had come to the Galapagos, after the islands rose from the sea as volcanoes, and then changed over time in isolation on the islands.
Darwin began to speculate on how new species could arise by natural observable causes. His idiosyncratic eclecticism led him to investigate some unconventional evidence. He made countless inquiries of animal breeders, both farmers and hobbyists like pigeon fanciers, trying to understand how they made distinct breeds of plants and animals. Gradually Darwin concluded that organisms were infinitely variable, and that the supposed limits or barriers to species was a belief without foundation. In modern terms we would say that Darwin came to accept that life evolves. One conventional view of the time was that species had been created where they are now found, in accordance with the environment. Few men of science then held to the view that there had been only a single species creation event. The fossil evidence seemed to show very many creations had occurred in different geological eras.
Darwin then sought to explain how living forms changed over time. He was familiar with the evolutionary speculations proposed earlier by his grandfather Erasmus Darwin and by the great French zoologist Jean-Baptiste Lamarck. But already Darwin's theorizing had extended in novel directions. He was thinking of the history of life not as a number of independent lineages somehow impelled to progress upwards from monads to monkeys. Instead Darwin saw all life as a single genealogical tree, branching and rebranching. Thus similarities between different kinds of living things would be expected from their joint ancestry or common descent. (See Hodge 2005) Darwin's speculations and early theorizing were recorded in a series of notebooks similar to those he kept during the Beagle voyage.
In September 1838 Darwin read Thomas Malthus's Essay on the Principle of Population (1798). As Janet Browne has written, Darwin was 'clearly following up lines of inquiry relating to individual variation, averages, and chance, as well as seeking information on human population statistics.' (Browne 1995, p. 385) Malthus argued that human population growth, unless somehow checked, would necessarily outstrip food production. Population growth was geometrical. For example, two parents might have four children, each of whom could have four children, whose children could also have four children. Thus in four generations there would be an increase from 2 to 4 to 24 to 96 and so forth.
The focus of this argument inspired Darwin. He realised that an enormous proportion of living things are always destroyed before they can reproduce. This must be true because every species would otherwise breed enough to fill the earth in a few hundred generations. Instead populations remain roughly stable year after year. The only way this can be so is that most offspring (from pollen, to seeds and eggs) do not survive long enough to reproduce.
Darwin, already concentrating on how new varieties of life might be formed, suddenly realised that the key was whatever made a difference between those that survive to reproduce and those that do not. He came to call this open-ended collection of causes 'natural selection' because it was analogous to breeders choosing which individuals to breed from and thus changing a breed markedly over time.
As Darwin wrote in his Autobiography in 1876: 'In October 1838, that is, fifteen months after I had begun my systematic enquiry, I happened to read for amusement Malthus on Population, and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this would be the formation of new species. Here, then, I had at last got a theory by which to work'. Below is the famous passage from Darwin's notebook where these ideas were first recorded:
[Sept] 28th. Even the energetic language of <Malthus> «Decandoelle» does not convey the warring of the species as inference from Malthus.— «increase of brutes, must be prevented soley by positive checks, excepting that famine may stop desire.—» in Nature production does not increase, whilst no checks prevail, but the positive check of famine & consequently death..
...—The final cause of all this wedging, must be to sort out proper structure, and adapt it to change.—to do that for form, which Malthus shows is the final effect by means however of volition of this populousness on the energy of man. One may say there is a force like a hundred thousand wedges trying [to] force every kind of adapted structure into the gaps in the economy of nature, or rather forming gaps by thrusting out weaker ones. [Notebook D 134e-135e]
Or, as Darwin later put it in the Origin of Species (1859):
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.
Therefore only the survivors would pass on their form and abilities. Their characteristics would persist and multiply whilst characteristics of those that did not live long enough to reproduce would decrease. Darwin did not know precisely how inheritance worked—genes and DNA were totally unknown. Nevertheless he appreciated the crucial fact of inheritance. Offspring resemble their parents. Darwin thought in terms of populations of diverse heritable things with no essence—not representatives of ideal types as many earlier thinkers had done. From his observations and experiments with domesticated and wild plants and animals he could find no limits to the extent organic forms could vary and change through generations. Thus the existing species in the world were related not along a 'chain of being' or separated into artificially separate species categories but were all related on a genealogical family tree through 'descent with modification'.
As Darwin wrote in the Origin of Species (1859):
why should the species which are supposed to have been created in the Galapagos Archipelago, and nowhere else, bear so plain a stamp of affinity to those created in America? There is nothing in the conditions of life, in the geological nature of the islands, in their height or climate, or in the proportions in which the several classes are associated together, which resembles closely the conditions of the South American coast: in fact there is a considerable dissimilarity in all these respects. On the other hand, there is a considerable degree of resemblance in the volcanic nature of the soil, in climate, height, and size of the islands, between the Galapagos and Cape de Verde Archipelagos: but what an entire and absolute difference in their inhabitants! The inhabitants of the Cape de Verde Islands are related to those of Africa, like those of the Galapagos to America. I believe this grand fact can receive no sort of explanation on the ordinary view of independent creation; whereas on the view here maintained, it is obvious that the Galapagos Islands would be likely to receive colonists, whether by occasional means of transport or by formerly continuous land, from America; and the Cape de Verde Islands from Africa; and that such colonists would be liable to modification;—the principle of inheritance still betraying their original birthplace.
Darwin also identified another means by which some individuals would have descendants and others would not. He later called this sexual selection. This theory explained why the male sex in many species produce colourful displays or specialised body parts to attract females or to compete against other males. Those males who defeat other males, or are selected for breeding by females leave more offspring and so subsequent generations resemble them more than those who succeed less often. As Darwin pointed out, "A hornless stag or spurless cock would have a poor chance of leaving offspring." (Origin p. 88)
Darwin, deeply studied in the sciences of his time, yet living somewhat independently from his colleagues, was able to think in new ways and to conceive of worlds quite unimaginable to his more orthodox friends. However, the legend of Darwin as a lone genius discovering evolution on the Galapagos Islands is now known by historians to be a groundless myth.
It is now clear that Darwin did not keep his ideas about species changing secret; he discussed them with many friends, family and colleagues during succeeding years. But his full-time occupation before and long after he became an evolutionist was the publication of his recollections and scientific work resulting from the Beagle voyage.
Darwin in 1840. Watercolour by George Richmond. Reproduced courtesy of the Darwin Heirlooms Trust.
He married his cousin Emma Wedgwood (1808-1896) in 1839. Darwin's many acute and innovative books and articles forged a great reputation as a geologist, zoologist and scientific traveller. His eight years grueling work on barnacles, published 1851-4 enhanced his reputation as an authority on taxonomy as well as geology and the distribution of flora and fauna as in his earlier works. Nevertheless there is no reason to allege, as is so often done, that Darwin needed to supplement his reputation or skills before he could publish his species theory. Marine invertebrates had been of central interest for Darwin since his student days in Edinburgh. During the Beagle voyage a large percentage of his notes were devoted to them, and he did not give this class of organisms to another expert to identify but kept them for himself.
Extract from Darwin's catalogue of microscope slides of barnacle specimens.
Darwin conducted breeding experiments with animals and plants and corresponded and read widely for many years to refine and substantiate his theory of evolution. In 1842 he prepared an essay outlining his theory. This was greatly expanded in another essay written in 1844. After completing his work on barnacles Darwin immediately turned to his theory to explain species. He was more than half way through a great work on the subject when he was interrupted on 18 June 1858 by a letter from an English naturalist and collector, Alfred Russel Wallace (1823-1913). Wallace was then collecting in South East Asia. In an essay enclosed, Wallace described his ideas 'On the Tendency of Varieties to Depart Indefinitely From the Original Type'. Darwin was struck by the similarity. He sent the letter on to Lyell the same day as requested, and it was decided, together with Darwin's friend J. D. Hooker, to avoid competition for priority, to publicise abstracts by both men as soon as possible. The papers were read, in the absence of Darwin and Wallace, at a meeting of the Linnean Society of London on 1 July 1858 and later published in their Proceedings. Darwin was urged by friends to publish an 'abstract' or overview of his work-in-progress on natural selection. This abstract became one of the most famous books ever written: On the Origin of Species (1859).
Although Darwin convinced most of the scientific community within 15-20 years that descent with modification, or evolution, was true, many rejected natural selection as the primary mechanism. Darwin was not the first to propose that species can change. A glance at his 'An historical sketch of the progress of opinion on the origin of species' shows that Darwin made no pretence to have originated or discovered evolution per se. However, Darwin's understanding of branching descent was more accurate, refined and convincing than his predecessors who considered, for example, that the members of one genus might be commonly derived. We know that a wide popular literature such as George Combe's Constitution of Man (1828) and the anonymous Vestiges of the Natural History of Creation (1844) had already shocked and converted vast popular audiences to belief in the power of natural laws to control the development of nature and society. Historians of science now believe that Darwin's effect was, as James Secord put it, a 'palace coup' amongst elite men of science rather than a revolution. Indeed recent research suggests that the reaction to Darwin's Origin was less of a furore than once believed. (Fleming & Goodall 2002) Nevertheless to the end of his life Darwin was regarded as a great scientific revolutionary who had overturned the ideas of his generation.
Darwin, as an unquestionably respectable authority in elite science, publicly threw his weight on the side of evolution, and soon young allies like Hooker, T. H. Huxley, and John Tyndall publicly threw their own weight towards the same position. Darwin's name is so linked with evolution because his works convinced the international scientific community that evolution was true. In the two decades after the publication of Origin the great majority of the scientific community came to accept that Darwin was right about the evolution of life. But natural selection was often not accepted. In fact, a generation of biologists regarded Darwin as correct in uncovering the evolution of life but mistaken in stressing natural selection. Natural selection's canonisation had to wait until the modern synthesis of Darwinism with Mendelian genetics in the 1930s.
Like Combe, Charles Babbage, Robert Chambers, Herbert Spencer and countless other authors before him, Darwin represented his doctrine as furthering the domain of natural laws. We see this in the following epigraph Darwin used for the Origin of Species:
" But with regard to the material world, we can at least go so
far as this-we can perceive that events are brought about not by
insulated interpositions of Divine power, exerted in each particular
case, but by the establishment of general laws."
W. WHEWELL : Bridgewater Treatise.
Darwin even saw the power of his law of natural selection extending beyond life to what we would call psychology, linguistics and to society and history (see for example Descent of Man, 1871, chapter 3).
In the Origin of Species Darwin first tried to convince his readers that organisms are malleable and not fixed natural kinds. He demonstrated that domesticated plants and animals were known to be highly variable and to have changed so much as to be classified as different species if they were not already familiar.
He then showed that the existence and abundance of organisms was dependent on many factors, which tended to hold their numbers in check such as climate, food, predation, available space etc.
Only then did Darwin set about showing the effects of differential death and survival on reproduction and the persistence and diversification of forms—natural selection. In other words Darwin's theory of evolution has three main elements or requirements: variation, selection and heredity. If all individual life forms are unique, which no one denied, and these differences could make a difference to which organisms lived to reproduce and which did not, then, if these differences could be inherited by offspring, subsequent generations would be descended from those which were lucky enough to survive.
An illustrative example is seen in the recent work of biologists in the Galapagos Islands. During a drought season when no new seeds were produced for an island's finches to eat, the birds were forced to hunt for remaining seeds on the ground. Soon all the visible seeds had been devoured. It so happened that those with slightly thicker beaks than average could turn over stones a little bit better than the rest to find the remaining seeds and so the birds which survived the famine tended to be thicker beaked. When the drought ended and the birds again had young, this new generation had slightly thicker beaks. This is an example of Darwinian evolution observed and measured in the field. (See Weiner. 1994. Beak of the Finch.)
Darwin's theory of genealogical evolution (as opposed to earlier theories by Lamarck or Vestiges which entailed independent lineages unfolding sequentially because of an innate tendency towards progress) made sense of a host of diverse kinds of evidence such as the succession of fossil forms in the geological record, geographical distribution of life (biogeography), recapitulative appearances in embryology, homologies like the hand of a man and the wing of a bat, vestigial organs, nesting taxonomic relationships observed throughout the world and so forth.
The famous last paragraph of the Origin of Species is a concise and eloquent précis of Darwin's vision:
It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, being Growth with Reproduction; Inheritance which is almost implied by reproduction; Variability from the indirect and direct action of the external conditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less-improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. 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.
Modern readers often misunderstand the meaning of the title of Darwin's book. They take the origin of species to mean the origin of life. Then it is pointed out that Darwin 'failed' to throw light on the origin of life. Others seem to think that his book is called The origin of THE species i.e. aimed at human beings. But this was not Darwin's aim. Darwin argued that species—that is the different kinds of organisms in the world —come not from multiple unique creation events on each island or particular place—but instead that species are the modified descendants of earlier forms. Darwin demonstrated that the origination of species could be entirely explained by descent with modification and that a host of facts were inconsistent with the belief in spontaneous creations according to environmental circumstances or divine interventions.
The reactions to Darwin's evolutionary theories were varied and pronounced. In zoology, taxonomy, botany, palaeontology, philosophy, anthropology, psychology, literature and religion Darwin's work engendered profound reactions—many of which are still ongoing. Most disturbing of all, however, were the implications for the cherished uniqueness of man. Although Darwin refrained from discussing the derivation of any particular species, including man, in the Origin except for his famous sentence: 'Much light will be thrown on the origin of man and his history' many people who read the book could think only about what this genealogical view of life meant for human beings. This is a subject Darwin later took up in The Descent of Man (1871) and The Expression of the Emotions in Man and Animals (1872). In these brilliantly original and seminal works Darwin showed that there is no difference of kind between man and other animals, but only of degree. Rather than an unbridgeable gulf, Darwin showed there is a gradation of change not only between man and other animals, but between all organic forms which is a consequence of the gradual change continuously and cumulatively operating over time.
Darwin's extraordinary achievements are not restricted to his early scientific works and his evolutionary works. His keen observation, imagination, curiosity and determination allowed him to make strikingly prescient contributions to ecology, botany and a dozen of what would later be distinct disciplines. Darwin was very impressed by the inter-relatedness of different species, climate and environment. He stressed that the life in any area was the outcome of an amazing history of struggle or 'great battle for life'. He proposed new solutions to how organisms spread across the globe. His numerous discoveries and theories are too numerous to list here. Only by reading his works themselves can one gain an accurate sense of Darwin's achievements.
His final book, The formation of vegetable mould through the action of worms (1881), was published the year before his death. In it Darwin made another important contribution, and, characteristicly, revealed the amazing complexity and importance of a natural process of gradual accumulation, which no one seemed to have grasped before, and that had all along been under our feet.
A myth about Darwin still circulates today—that he repented of evolutionism or converted to Christianity on his deathbed. These stories are usually told by those who would like them to be true, but they are not. There are no mysteries surrounding Darwin's death; his relatives present at the time wrote detailed accounts of his last hours. The history of the legend, however, is revealed in James Moore, The Darwin legend (1994). For most of his life Darwin was not an atheist, but a deist; that is he believed that a creator had designed the universe and set up natural laws according to which all of nature was unwaveringly governed. It was the pursuit of a man of science to discover the laws by which nature operated. He discussed his religious views in his autobiography (these appear, however, only in the 1958 edition by Nora Barlow with original omissions restored.)
Charles Darwin was a kind, good-humoured, pleasant man, unassuming and profoundly modest. He suffered from ill health much of his adult life. We will probably never know the causes for his illness. He nevertheless remained driven to understand nature and to remain part of the elite scientific world he respected and admired. Darwin died in April 1882 and is buried in Westminster Abbey.
After his death Darwin's private papers were mostly preserved and many of these were later deposited in Cambridge University Library. See Darwin's papers online.
In 1909 over 400 scientists and dignitaries from 167 different countries gathered at Cambridge to celebrate the centenary of Darwin's birth and the fiftieth anniversary of the publication of On the Origin of Species. The event was an unprecedented success - never before had such a celebration been held, not for an institution or a nation - but for an individual scientist. In the year 2009 we are witnessing another unprecedented celebration of an extraordinary man.
An extremely useful reference work for almost anything relating to Darwin is:
Freeman, Charles Darwin: A companion. 2d online edition. (2007) Text
For more detailed accounts of Darwin's life on this site see:
The autobiography of Charles Darwin 1809-1882. With the original omissions restored. (1958) Text
To learn more about Darwin:
Janet Browne, Charles Darwin: Voyaging.
Janet Browne, Charles Darwin: The power of place.
Janet Browne, Darwin's Origin of Species: A biography.
John van Wyhe, Darwin. (2008)
M. T. Ghiselin, Darwin: A reader's guide. Occasional Papers of the California Academy of Sciences (2009)