For other people of the same surname, and places and things named after Charles Darwin, see
Darwin.
Charles Robert Darwin (12 February 1809 –
19 April 1882) was an English naturalist.[I] After becoming eminent among scientists for his field work and
inquiries into geology, he proposed and provided scientific
evidence that all species of life have evolved over time from
one or a few common ancestors through the process of natural selection.[1] The
fact that evolution occurs became accepted by the scientific community and the general public in his lifetime, while his theory of natural selection came to be widely seen as the primary explanation of the process of evolution in the
1930s,[1] and now forms the basis of modern evolutionary theory. In modified form, Darwin's scientific discovery remains the
foundation of biology, as it provides a unifying logical
explanation for the diversity of life.[2]
Darwin developed his interest in natural history while studying first medicine at
Edinburgh University, then theology at
Cambridge.[3] His five-year voyage on the
Beagle established him as a geologist whose
observations and theories supported Charles Lyell's uniformitarian ideas, and publication of his journal of the voyage made him famous as a popular author. Puzzled by the geographical
distribution of wildlife and fossils he collected on the voyage, Darwin investigated the
transmutation of species and conceived his theory of natural selection in 1838.
Having seen others attacked as heretics for such ideas, he confided only in his closest friends
and continued his extensive research to meet anticipated objections.[4] In 1858, Alfred Russel Wallace sent him an essay
describing a similar theory, causing the two to publish their theories early in a joint publication.[5]
His 1859 book On the Origin of Species established evolution by
common descent as the dominant scientific explanation of diversification in nature. He
examined human evolution and sexual selection
in The Descent of Man, and Selection in Relation to
Sex, followed by The Expression of the Emotions
in Man and Animals. His research on plants was published in a series of books, and in his final book, he examined
earthworms and their effect on soil.[6]
In recognition of Darwin's pre-eminence, he was buried in Westminster Abbey, close
to John Herschel and Isaac Newton.[7]
Biography
Early life
-
The seven-year-old Charles Darwin in 1816, one year before his mother's death.
Charles Darwin was born in Shrewsbury, Shropshire, England on 12 February
1809 at his family home, the Mount.[8] He was the fifth of six children of wealthy society doctor and
financier Robert Darwin, and Susannah
Darwin (née Wedgwood). He was the grandson of Erasmus Darwin on his
father's side, and of Josiah Wedgwood on his mother's side. Both families were largely
Unitarian, though the Wedgwoods were adopting Anglicanism. Robert Darwin, himself quietly a freethinker, made a nod
toward convention by having baby Charles baptised in the Anglican Church.
Nonetheless, Charles and his siblings attended the Unitarian chapel with their mother, and in 1817, Charles joined the day
school, run by its preacher. In July of that year, when Charles was eight years old, his mother died. From September 1818, he
attended the nearby Anglican Shrewsbury School as a boarder.[9]
Darwin spent the summer of 1825 helping his father treat the poor of Shropshire as an apprentice doctor. In the autumn, he
went to the University of Edinburgh, Scotland, to study medicine, but he was
revolted by the brutality of surgery and neglected his medical studies. He learned
taxidermy from John Edmonstone, a freed black slave
who told him exciting tales of the South American rainforest. Later, in The Descent
of Man, he used this experience as evidence that "Negroes and Europeans" were closely related despite superficial
differences in appearance.[10]
In Darwin's second year, he joined the Plinian Society, a student group interested in natural history.[11] He became a
keen pupil of Robert Edmund Grant, a proponent of Jean-Baptiste Lamarck's theory of evolution by
acquired characteristics, which Charles's grandfather Erasmus had
also advocated. On the shores of the Firth of Forth, Darwin joined in Grant's
investigations of the life cycle of marine animals. These studies found evidence for
homology, the radical theory
that all animals have similar organs which differ only in complexity, thus showing
common descent.[12]
In March 1827, Darwin made a presentation to the Plinian of his own discovery that the black spores often found in
oyster shells were the eggs of a skate leech.[13] He also sat in on Robert
Jameson's natural history course, learning about stratigraphic geology, receiving training in classifying plants, and assisting with
work on the extensive collections of the University Museum, one of the largest museums in
Europe at the time.[14]
In 1827, his father, unhappy at his younger son's lack of progress, shrewdly enrolled him in a Bachelor of Arts course at Christ's College,
Cambridge to qualify as a clergyman, expecting him to get a good income as an Anglican parson.[15] However, Darwin preferred
riding and shooting to studying.[16] Along with his cousin William Darwin Fox, he became engrossed in the craze at the time for the competitive collecting of
beetles.[17] Fox
introduced him to the Reverend John Stevens Henslow, professor of botany, for expert advice on beetles. Darwin subsequently joined Henslow's natural history course and became his
favourite pupil, known to the dons as "the man who walks with Henslow".[18][19] When exams drew near, Darwin focused on his studies and received private instruction from Henslow.
Darwin was particularly enthusiastic about the writings of William Paley, including the
argument for divine design in nature.[20] It has been argued that Darwin's enthusiasm for Paley's religious adaptationism
paradoxically played a role even later, when Darwin formulated his theory of natural selection.[21] In his finals in January 1831, he performed well in theology and, having scraped through in classics, mathematics and physics, came tenth out of a pass list of 178.[22]
Residential requirements kept Darwin at Cambridge until June. Following Henslow's example and advice, he was in no rush to
take Holy Orders. Inspired by Alexander von
Humboldt's Personal Narrative, he planned to visit the Madeira Islands
with some classmates after graduation to study natural history in the tropics. To prepare
himself, Darwin joined the geology course of the Reverend Adam Sedgwick and, in the
summer, went with him to assist in mapping strata in Wales.[23] After a fortnight with student friends at Barmouth, he returned home to find a letter from Henslow recommending Darwin as a suitable (if unfinished)
naturalist for the unpaid position of gentleman's companion to Robert FitzRoy, the
captain of HMS Beagle, which was to leave in four weeks on an expedition to chart the
coastline of South America. His father objected to the planned two-year voyage, regarding it as a waste of time, but was
persuaded by his brother-in-law, Josiah Wedgwood, to agree to his son's
participation.[24]
Journey of the Beagle
-
The voyage of the
Beagle.
The Beagle survey took five years, two-thirds of which Darwin spent on land. He carefully noted a rich variety of
geological features, fossils and living organisms, and methodically collected an enormous number
of specimens, many of them new to science.[1] At
intervals during the voyage he sent specimens to Cambridge together with letters about his findings, and these established his
reputation as a naturalist. His extensive detailed notes showed his gift for theorising and formed the basis for his later work.
The journal he originally wrote for his family, published as The Voyage of the
Beagle, summarises his findings and provides social, political and anthropological insights into the wide range of people he met, both native and colonial.[25]
While on board the ship, Darwin suffered badly from seasickness.[26] In October 1833 he caught a fever in Argentina, and in July
1834, while returning from the Andes down to Valparaíso, he fell ill and spent a month in
bed.[27]
Before they set out, FitzRoy gave Darwin the first volume of Charles Lyell's
Principles of Geology, which explained landforms as the outcome of gradual processes over huge periods of
time.[II] On their first stop
ashore at St Jago, Darwin found that a white band high in the volcanic rock cliffs consisted of baked coral fragments and shells. This
matched Lyell's concept of land slowly rising or falling, giving Darwin a new insight into the geological history of the island
which inspired him to think of writing a book on geology.[28] He went on to make many more discoveries, some of them particularly dramatic.[1] He saw stepped plains of shingle and seashells in
Patagonia as raised beaches, and after experiencing an
earthquake in Chile saw mussel-beds stranded above high tide
showing that the land had just been raised. High in the Andes he saw several fossil trees that had
grown on a sand beach, with seashells nearby. He theorised that coral atolls form on sinking
volcanic mountains, and confirmed this when the Beagle surveyed the Cocos
(Keeling) Islands.[29]
In South America, Darwin found and excavated rare fossils of gigantic extinct mammals in
strata with modern seashells, indicating recent extinction and no change in climate or signs of catastrophe. Though he correctly
identified one as a Megatherium and fragments of armour reminded him of the local
armadillo, he assumed his finds were related to African or European species and it was a
revelation to him after the voyage when Richard Owen showed that they were closely related
to living creatures exclusively found in the Americas.[30]
As
HMS Beagle surveyed the coasts of
South
America, Darwin began to theorise about the wonders of nature around him.
Lyell's second volume, which argued against evolutionism and explained species
distribution by "centres of creation", was sent out to Darwin. He puzzled over all he saw, and his ideas went beyond
Lyell.[31] In Argentina, he found that two types of
rhea had separate but overlapping territories. On the Galápagos Islands, he collected mockingbirds and
noted that they were different depending on which island they came from. He also heard that local Spaniards could tell from their
appearance on which island tortoises originated, but thought the creatures had been imported by
buccaneers.[32] In
Australia, the marsupial rat-kangaroo and the platypus seemed so unusual that Darwin thought it was
almost as though two distinct Creators had been at work.[33]
In Cape Town he and FitzRoy met John Herschel, who
had recently written to Lyell about that "mystery of mysteries", the origin of species. When organising his notes on the return
journey, Darwin wrote that if his growing suspicions about the mockingbirds and tortoises were correct, "such facts undermine the
stability of Species", then cautiously added "would" before "undermine".[34] He later wrote that such facts "seemed to me to throw some light on the origin of species".[35]
Three natives who had been taken from Tierra del Fuego on the Beagle's
previous voyage were taken back there to become missionaries. They had become "civilised" in England over the previous two years,
yet their relatives appeared to Darwin to be "miserable, degraded savages".[36] A year on, the mission had been abandoned and only Jemmy
Button spoke with them to say he preferred his harsh previous way of life and did not want to return to England. Because
of this experience, Darwin came to think that humans were not as far removed from animals as his friends then believed, and saw
differences as relating to cultural advances towards civilisation rather than being racial. He detested the slavery he saw elsewhere in South America, and was saddened by the effects of European settlement on
Aborigines in Australia and Maori in New
Zealand.[37]
Captain FitzRoy was committed to writing the official Narrative of the Beagle voyages, and near the end of the
voyage, he read Darwin's diary and asked him to rewrite this Journal to provide the third volume, on natural
history.[38]
Inception of Darwin's evolutionary theory
-
While still a young man, Charles Darwin joined the scientific élite.
While Darwin was still on the voyage, Henslow fostered his former pupil's
reputation by giving selected naturalists access to the fossil specimens and a pamphlet of Darwin's geological letters.[39] When the Beagle returned on 2 October 1836, Darwin was a celebrity in scientific circles. After visiting his
home in Shrewsbury and seeing relatives, Darwin hurried to Cambridge to see Henslow, who
advised on finding naturalists available to describe and catalogue the collections, and agreed to take on the botanical
specimens. Darwin's father organised investments, enabling his son to be a self-funded gentleman scientist, and an excited Darwin went round the London
institutions being fêted and seeking experts to describe the collections. Zoologists had a huge backlog of work, and there was a
danger of specimens just being left in storage.[40]
An eager Charles Lyell met Darwin for the first time on 29
October and soon introduced him to the up-and-coming anatomist Richard Owen, who had
the facilities of the Royal College of Surgeons at his disposal to
work on the fossil bones collected by Darwin. Owen's surprising results included gigantic sloths,
a hippopotamus-like skull from the extinct rodent
Toxodon, and armour fragments from a huge extinct armadillo (Glyptodon), as Darwin had initially surmised.[41] The fossil creatures were unrelated to African animals, but closely
related to living species in South America.[42]
In mid-December, Darwin moved to Cambridge to organise work on his collections and rewrite his Journal.[43] He wrote his first paper, showing that the South American
landmass was slowly rising, and with Lyell's enthusiastic backing read it to the Geological Society of London on 4 January
1837. On the same day, he presented his mammal and bird specimens to the Zoological Society. The ornithologist John Gould soon
revealed that the Galapagos birds that Darwin had thought a mixture of blackbirds,
"gross-beaks" and finches, were, in fact, twelve
separate species of finches. On 17 February
1837, Darwin was elected to the Council of the Geographical Society, and in his presidential
address, Lyell presented Owen's findings on Darwin's fossils, stressing geographical continuity of species as supporting his
uniformitarian ideas.[44]
Darwin's first sketch of an
evolutionary tree from his
First Notebook on
Transmutation of Species (1837)
On 6 March 1837, Darwin moved to London to be close to this
work, and joined the social whirl around scientists and savants such as Charles Babbage, who thought that God preordained life by natural
laws rather than ad hoc miraculous creations. Darwin lived near his freethinking brother Erasmus, who was part of this
Whig circle and whose close friend the writer Harriet Martineau promoted the ideas of Thomas Malthus
underlying the Whig "Poor Law reforms" aimed at discouraging the poor from breeding beyond
available food supplies. John Herschel's question on the origin of species was widely
discussed. Medical men including Dr. Gully even joined Grant in endorsing transmutation of species, but
to Darwin's scientist friends such radical heresy attacked the divine basis of
the social order already under threat from recession and riots.[45]
Gould now revealed that the Galapagos mockingbirds from different islands
were separate species, not just varieties, and the "wrens" were yet another species of finches.
Darwin had not kept track of which islands the finch specimens were from, but found information from the notes of others on the
Beagle, including FitzRoy, who had more carefully recorded their own collections. The zoologist Thomas Bell showed that the Galápagos tortoises were
native to the islands. By mid-March, Darwin was convinced that creatures arriving in the islands had become altered in some way
to form new species on the different islands, and investigated transmutation while noting his speculations in his "Red Notebook"
which he had begun on the Beagle. In mid-July, he began his secret "B" notebook on transmutation, and on page 36 wrote "I
think" above his first sketch of an evolutionary tree.[46]
Overwork, illness, and marriage
As well as launching into this intensive study of transmutation, Darwin
became mired in more work. While still rewriting his Journal, he took on editing and publishing the expert reports on his
collections, and with Henslow's help obtained a Treasury grant of £1,000 to sponsor this
multi-volume Zoology of the Voyage of H.M.S. Beagle. He
agreed to unrealistic dates for this and for a book on South American Geology supporting Lyell's ideas. Darwin finished
writing his Journal around 20 June 1837 just as
Queen Victoria came to the throne, but then had
its proofs to correct.[47]
Darwin's health suffered from the pressure. On 20 September 1837, he had "palpitations of the heart". On doctor's advice that a month of recuperation was needed, he went to
Shrewsbury then on to visit his Wedgwood relatives at Maer Hall, but found them too eager for
tales of his travels to give him much rest. His charming, intelligent, and cultured cousin Emma
Wedgwood, nine months older than Darwin, was nursing his invalid aunt. His uncle Jos pointed out an area of ground where cinders had disappeared under loam and suggested that this might have been the work of earthworms. This
inspired a talk which Darwin gave to the Geological Society on 1 November, the first
demonstration of the role of earthworms in soil formation.[48]
William Whewell pushed Darwin to take on the duties of Secretary of the Geological
Society. After first declining this extra work, he accepted the post in March 1838.[49] Despite the grind of writing and editing, remarkable progress was made on
transmutation. While keeping his developing ideas secret, Darwin took every opportunity to question expert naturalists and,
unconventionally, people with practical experience such as farmers and pigeon
fanciers.[1][50] Over time his research drew on information from his relatives and children, the
family butler, neighbours, colonists and former shipmates.[51] He included mankind in his speculations from the outset, and on seeing an ape in the zoo on 28 March 1838 noted its child-like
behaviour.[52]
The strain took its toll, and by June he was being laid up for days on end with stomach problems, headaches and heart
symptoms.[53] For the rest of his life, he was repeatedly
incapacitated with episodes of stomach pains, vomiting, severe boils, palpitations,
trembling and other symptoms, particularly during times of stress, such as when attending meetings or dealing with controversy
over his theory. The cause of Darwin's illness was unknown during his lifetime,
and attempts at treatment had little success. Recent attempts at diagnosis have suggested Chagas
disease caught from insect bites in South America, Ménière's disease, or
various psychological illnesses as possible causes, without any conclusive results.[54]
On 23 June 1838, he took a break from the pressure of work and
went "geologising" in Scotland. He visited Glen Roy in glorious weather to see the parallel
"roads", horizontal ledges cut into the hillsides. He thought that these were raised
beaches: they were later shown to have been shorelines of a glacial lake.[55]
Fully recuperated, he returned to Shrewsbury in July. Used to jotting down daily notes on animal breeding, he scrawled
rambling thoughts about career and prospects on two scraps of paper, one with columns headed "Marry" and "Not
Marry". Advantages included "constant companion and a friend in old age ... better than a dog anyhow", against points
such as "less money for books" and "terrible loss of time."[56] Having decided in favour, he discussed it with his father, then went to visit Emma on
29 July 1838. He did not get around to proposing, but against his
father's advice he mentioned his ideas on transmutation.[57]
Continuing his research in London, Darwin's wide reading now included "for amusement" the 6th edition of Malthus's An Essay on the Principle of
Population which calculates from the birth rate that human population could double every 25 years, but in practice
growth is kept in check by death, disease, wars and famine.[1][58] Darwin was well
prepared to see at once that this also applied to de Candolle's "warring of the
species" of plants and the struggle for existence among wildlife, explaining how numbers of a species kept roughly stable. As
species always breed beyond available resources, favourable variations would make organisms better at surviving and passing the
variations on to their offspring, while unfavourable variations would be lost. This would result in the formation of new
species.[59] On 28
September 1838 he noted this insight, describing it as a kind of wedging, forcing adapted
structures into gaps in the economy of nature as weaker structures were thrust out.[1] He now had a theory by which to work, and over the following months compared
farmers picking the best breeding stock to a Malthusian Nature selecting from variants thrown up by "chance" so that "every part
of [every] newly acquired structure is fully practised and perfected", and thought this analogy "the most beautiful part of my
theory".[60]
On 11 November, he returned to Maer and proposed to Emma, once more telling her his
ideas. She accepted, then in exchanges of loving letters she showed how she valued his openness, but her upbringing as a very
devout Anglican led her to express fears that his lapses of faith could endanger her hopes
to meet in the afterlife.[61] While he was house-hunting
in London, bouts of illness continued and Emma wrote urging him to get some rest, almost prophetically remarking "So don't be ill
any more my dear Charley till I can be with you to nurse you." He found what they called "Macaw Cottage" (because of its gaudy
interiors) in Gower Street, then moved his "museum" in over Christmas. The
marriage was arranged for 24 January 1839, but the Wedgwoods
set the date back. On the 24th, Darwin was honoured by being elected as Fellow of
the Royal Society.[62]
On 29 January 1839, Darwin and Emma Wedgwood were married at
Maer in an Anglican ceremony arranged to suit the Unitarians, then immediately caught the train to London and their new
home.[63]
Preparing the theory of natural selection for publication
-
Darwin had found the basis of his theory of natural selection, but was aware of how
much work remained to make it credible to his fiercely critical scientific colleagues. As Secretary of the Geological Society at
its meeting on 19 December 1838, he saw Owen and Buckland display their hatred of evolution when
destroying the reputation of his old Lamarckian teacher
