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Darwin Day: Why Charles Darwin Delayed Publishing On the Origin of Species — A Timeline (1809–1859)

📅 Last updated: 31 October 2026📖 23 dated entries, 1809–1859✎ By Nazish Fatima

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In short

Darwin Day: why Charles Darwin waited 20 years to publish On the Origin of Species, from his 1844 essay to Wallace's 1858 letter and the 1859 book.

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Every year on 12 February, Darwin Day marks the birth of Charles Darwin, the naturalist whose theory of evolution by natural selection changed how we understand life. Darwin was born on 12 February 1809, and his most famous book, On the Origin of Species, appeared on 24 November 1859. Yet he had worked out the theory 21 years earlier, written it down in 1842 and expanded it into a long essay in 1844. This timeline follows that gap, and the letter from Alfred Russel Wallace in June 1858 that finally ended it.

Charles Darwin photographed by Maull and Polyblank in 1855, while he was preparing his species theory
Charles Darwin in 1855, a year after he returned to the species question. Photo: Maull and Polyblank, via Wikimedia Commons, public domain.

💡 Short Answer

Darwin conceived natural selection in 1838 but published On the Origin of Species only in November 1859. He wanted overwhelming evidence, spent eight years on barnacles, and from 1856 was writing a huge treatise. He also knew the idea would be controversial. In June 1858 Alfred Russel Wallace sent him an essay with the same theory. Their papers were read jointly on 1 July 1858, and Darwin wrote the shorter book in 13 months.

⚡ Darwin and the Origin at a Glance
Darwin Day12 February (born 1809)
Idea of natural selectionSeptember 1838
Private drafts1842 sketch; 1844 essay
Wallace’s essay arrives18 June 1858
Joint presentationLinnean Society, 1 July 1858
Book published24 November 1859; 1,250 copies
⚡ Quick Answers — AI Overview Ready

Darwin Day and the Origin of Species: Key Questions

Why did Darwin wait so long to publish?
He wanted overwhelming evidence and a complete argument, he spent years on other research, including barnacles, and from 1856 he was writing a far larger book. He knew the idea would cause controversy. Wallace’s 1858 essay made publication urgent.
When was On the Origin of Species published?
John Murray published it in London with 24 November 1859 as the publication date. All 1,250 copies of the first printing were ordered by booksellers at Murray’s trade sale two days earlier.
Who else discovered natural selection?
Alfred Russel Wallace reached the same idea independently in the Malay Archipelago in February 1858 and sent his essay to Darwin. Their work was presented jointly at the Linnean Society of London on 1 July 1858.
What is Darwin Day?
An annual celebration of science on 12 February, Darwin’s birthday. It is not the anniversary of the Origin of Species, which was published on 24 November 1859.
📚 Key Takeaways

Darwin’s Delay in Nine Points

  • The voyage: HMS Beagle, 1831-1836, supplied the observations, not the theory.
  • The idea: Darwin accepted that species change in 1837 and found the mechanism after reading Malthus in September 1838.
  • The drafts: a 35-page pencil sketch in 1842 and a long essay in 1844, which he asked Emma to publish if he died.
  • The warning: the hostile reception of Vestiges in 1844 showed what happened to a thin argument.
  • The detours: geology books and eight years on barnacles, 1846-1854.
  • The big book: begun 14 May 1856; about 250,000 words and half finished by June 1858.
  • The shock: Wallace’s essay arrived on 18 June 1858.
  • The compromise: joint reading at the Linnean Society on 1 July 1858, arranged by Lyell and Hooker.
  • The book: written in 13 months and 10 days, published 24 November 1859.

Darwin’s Publication Timeline: Latest First

From the 1859 book back to Darwin’s birth in 1809. Each entry is colour-coded by phase, so the three stages the brief history often blurs, private writing, Wallace’s discovery and the joint presentation, stay distinct.

Early life & voyage, 1809–1836Private theory, 1837–1857Wallace & the 1858 crisisRoad to publication, 1858–1859
24 Nov 1859

On the Origin of Species is published Road to publication

LondonJohn Murray

What happened: Darwin’s book, On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life, was published in London by John Murray, with 24 November 1859 as the official publication date. The first printing was 1,250 copies.

The sale: Two days earlier, on 22 November, Murray offered the book to booksellers at his autumn trade sale. Orders exceeded the printing by about 250 copies, so the whole first edition was taken up before the publication date. That is the origin of the popular line that it “sold out on the first day”. Murray asked Darwin for a second edition at once.

What the book argued: Species are not fixed. Populations change over generations, and natural selection explains how adaptations and new species arise. Darwin built the case from domestic breeding, geographical distribution, fossils, comparative anatomy, embryology and classification, and he gave a whole chapter to “Difficulties on Theory”. The main text ran to 502 pages, with a single diagram: a branching tree of descent.

Why it matters: Twenty-one years after he first saw how natural selection could work, the argument was finally in print.
Title page of the 1859 first edition of On the Origin of Species by Charles Darwin, published by John Murray
Title page of the first edition, published by John Murray in November 1859. Image via Wikimedia Commons, public domain.
Oct 1859

Darwin finishes correcting the proofs Road to publication

Down House and IlkleyProof sheets

What happened: Darwin finished the last proof sheets in early October 1859, and then left for a water cure at Ilkley in Yorkshire, where he was staying when the book came out.

13 months and 10 days: He reckoned the book had cost him “13 months & 10 days” of work from the day he began the abstract in July 1858. He rewrote heavily in proof, worried about the length and style, and feared that Murray would lose money on it.

The title: The working title included the words “An Abstract of an Essay”. On Murray’s advice the word “abstract” was dropped, though Darwin still called the book an abstract in its introduction.

Why it matters: Even at the last stage Darwin treated the book as a summary of a larger work that never appeared.
Mar 1859

Darwin completes the manuscript Road to publication

Down HouseThe abstract becomes a book

What happened: By the middle of March 1859 Darwin had finished the last chapter of his abstract. Charles Lyell helped arrange publication with John Murray, who agreed terms in early April without reading the whole text.

Why it grew: Darwin had first planned a paper for the Linnean Society’s journal. Each argument needed examples, and each example needed answers to the obvious objections. The “abstract” became a book of 14 chapters.

Why it matters: The shortest version Darwin could accept was still a full-length book.
20 Jul 1858

Darwin begins writing the abstract on the Isle of Wight Road to publication

Sandown, Isle of WightWriting begins

What happened: With his family away from Down House to escape the scarlet fever outbreak, Darwin began writing the abstract of his species theory at Sandown on the Isle of Wight, where the family stayed until mid-August.

The method: He worked from the manuscript of his unfinished “big book” and his notes, cutting the references and much of the detail. He wrote to his cousin W. D. Fox on 21 July that he was “beginning to prepare an abstract” of his species theory.

Why it matters: This is the start of the 13 months and 10 days that produced the Origin.
20 Aug 1858

The Darwin-Wallace papers appear in print Road to publication

Journal of the Proceedings of the Linnean Society

What happened: The papers read on 1 July were published in the Society’s zoology journal under a joint title: “On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection”.

The reaction: There was little immediate reaction. In his address in May 1859 the Society’s president, Thomas Bell, said the year had not been marked by any of those “striking discoveries” that revolutionise a branch of science.

Why it matters: Natural selection was technically published in 1858, but almost no one noticed until the book.
5 Jul 1858

Darwin decides to write a fuller account Road to publication

Letter to Joseph HookerPlan

What happened: Writing to Joseph Hooker after the meeting, Darwin said he would start work on an abstract of his theory for the Linnean Society’s journal while the family was on the Isle of Wight.

The problem: He wanted the abstract to carry evidence, not just announce the idea. That made a journal paper too small almost from the start.

Why it matters: Wallace’s letter turned the big book into a race to write a short one.
1 Jul 1858

Darwin’s and Wallace’s work is presented jointly Wallace & 1858

Linnean Society of LondonBurlington House

What happened: The Society’s secretary read three documents: extracts from Darwin’s unpublished 1844 essay, part of his letter to Asa Gray of 5 September 1857, and Wallace’s essay “On the Tendency of Varieties to Depart Indefinitely from the Original Type”. Charles Lyell and Joseph Hooker had arranged the reading and introduced the papers with a covering letter.

Who was absent: Neither author attended. Darwin was at home after the death of his son. Wallace was in the Malay Archipelago and did not know about the arrangement until afterwards.

Why it was done this way: The order of the papers, Darwin’s first, set out the dates of his earlier work. Including Wallace’s essay in full recognised his independent discovery. Wallace later said he was satisfied with the arrangement.

Why it matters: The meeting settled priority on paper, but the theory still needed a book to persuade anyone.
28 Jun 1858

Darwin’s youngest son dies of scarlet fever Wallace & 1858

Down HouseFamily tragedy

What happened: Charles Waring Darwin, aged about 18 months, died of scarlet fever during an outbreak in the village of Downe. His daughter Henrietta, then 14, had been ill since early June and was struck down with diphtheria in the same weeks.

Why it matters here: Darwin left the handling of Wallace’s essay to Lyell and Hooker, and missed the Linnean meeting. The family then left Down House to escape the outbreak.

What it does not explain: The illness and grief came in the middle of the 1858 crisis. They are not the reason for the long delay before it, which had begun 20 years earlier.

Why it matters: The most important fortnight of Darwin’s scientific life was also one of his worst at home.
18 Jun 1858

Wallace’s essay reaches Darwin Wallace & 1858

Down HouseLetter from Ternate

What happened: Darwin received a manuscript essay from Alfred Russel Wallace, then collecting in the Malay Archipelago. Wallace asked Darwin, if he thought it good enough, to send it on to Charles Lyell.

Darwin’s reaction: Darwin forwarded it the same day. “Your words have come true with a vengeance that I shd. be forestalled,” he wrote to Lyell. “If Wallace had my M.S. sketch written out in 1842 he could not have made a better short abstract!”

A disputed date: The 18 June date comes from Darwin’s letter to Lyell. Some historians have argued that the essay arrived earlier and that Darwin held it back; the Darwin Correspondence Project and most recent research accept 18 June.

Why it matters: Darwin now had to protect the history of his own work without being unfair to Wallace.
Portrait of naturalist Alfred Russel Wallace in 1862
Alfred Russel Wallace in 1862, four years after his essay reached Darwin. Photo: unknown photographer, via Wikimedia Commons, public domain.
Feb 1858

Wallace reaches natural selection independently Wallace & 1858

Ternate, Malay ArchipelagoThe Ternate essay

What happened: During a bout of malarial fever, Wallace thought about Malthus’s essay on population and saw that in every generation the less fit would die and the better adapted would survive. He wrote out the idea over the next two evenings and posted it to Darwin, whom he knew to be interested in the species question.

His route to the idea: Wallace had travelled in the Amazon from 1848 to 1852 and in the Malay Archipelago from 1854. His 1855 paper on the “law” governing the introduction of new species had already shown he was close to the answer.

Why it matters: Two naturalists, working on opposite sides of the world, reached the same mechanism through the same book.
5 Sep 1857

Darwin outlines natural selection to Asa Gray Private theory

Letter to Harvard botanistWritten evidence

What happened: Darwin sent the American botanist Asa Gray an abstract of his theory, including natural selection and the “principle of divergence”, which explained why descendants spread into different ways of life.

Why it mattered later: The letter was dated and in another person’s hands. In July 1858 an extract from it was read at the Linnean Society as proof that Darwin’s ideas predated Wallace’s essay.

Why it matters: A private letter became part of the public record of priority.
14 May 1856

Darwin begins his “big book” Private theory

Down HouseNatural Selection

What happened: Lyell, who had read Wallace’s 1855 paper and discussed the theory with Darwin in April 1856, urged him to publish before someone else did. Darwin began writing on 14 May 1856.

The scale: He first considered a short sketch, but could not bring himself to publish without the evidence. The project became a treatise called Natural Selection. By June 1858 he had written about ten and a half chapters, roughly a quarter of a million words, and was about halfway through.

Why it matters: The book Darwin was writing in 1858 was far bigger than the one he published.
Sep 1855

Wallace’s “Sarawak Law” paper Wallace & 1858

Annals and Magazine of Natural HistoryWallace

What happened: Writing from Sarawak in Borneo, Wallace published “On the Law which has Regulated the Introduction of New Species”. It argued that every species had come into existence close in space and time to a related species.

Why it mattered: The paper did not give a mechanism, but Lyell read it as a sign that someone else was close to Darwin’s idea and began pressing him to publish. Darwin and Wallace started corresponding in 1856 and 1857.

Why it matters: The warning came three years before the letter that forced Darwin’s hand.
9 Sep 1854

Darwin returns to the species question Private theory

Down HouseSorting the notes

What happened: On the same day he finished eight years of work on barnacles, Darwin began “sorting notes for Species Theory”, in the words of his own journal.

What he worked on: Over the next two years he ran experiments on whether seeds survive in seawater, bred and skeletonised fancy pigeons, gathered data on variation in plants and animals, and wrote to naturalists around the world for facts on distribution and breeding.

Why it matters: The theory was 16 years old, but Darwin was still testing it.
1846-1854

Eight years on barnacles Private theory

Down HouseFour monographs

What happened: Darwin began a study of a single odd barnacle in October 1846 and ended up revising the whole group. The work produced four monographs between 1851 and 1854 and won him the Royal Society’s Royal Medal in 1853.

Why it is part of the story: It is often described as a detour, but it gave Darwin first-hand knowledge of variation and classification, and the standing of a working specialist rather than a speculator.

Why it matters: Darwin earned his authority as a taxonomist before he asked anyone to accept his theory.
23 Apr 1851

The death of Annie Darwin Private theory

MalvernFamily

What happened: Darwin’s eldest daughter, Anne, died at the age of ten at Malvern, where she had been taken for treatment. Darwin was devastated.

Why it is mentioned: Her death is often linked to the loss of Darwin’s remaining Christian faith. It is part of the background to his later reluctance to cause pain to his devout wife, Emma, through public controversy.

Why it matters: Darwin’s private life and his science were never fully separate.
Oct 1844

Vestiges causes a sensation Private theory

LondonAnonymous evolutionary book

What happened: Vestiges of the Natural History of Creation, published anonymously (its author was the Edinburgh publisher Robert Chambers), argued that life had developed through natural laws. It became a best seller.

The reaction: Scientists attacked it fiercely for errors of fact and loose argument. Darwin followed the reviews closely. He concluded that a theory of transmutation would be dismissed unless it rested on far more evidence.

Why it matters: Darwin learned from someone else’s mistakes what would happen to a thin argument.
5 Jul 1844

Darwin finishes a long essay and plans for his death Private theory

Down HouseLetter to Emma Darwin

What happened: Darwin expanded his 1842 sketch into a long essay and had a fair copy made. On 5 July 1844 he wrote to his wife, Emma, asking that if he died suddenly she should pay an editor £400 to complete and publish it.

What it shows: Darwin was convinced the theory mattered. He did not want it lost, but he did not think the essay strong enough to publish while he could still improve it. In January that year he had told Joseph Hooker that admitting species were not immutable was “like confessing a murder”.

Why it matters: The theory existed in near-complete form 15 years before publication.
1842

The first written sketch of the theory Private theory

Maer and Shrewsbury35-page pencil sketch

What happened: In May and June 1842, while visiting family, Darwin wrote a short pencil sketch of about 35 pages setting out descent with modification and natural selection. In September the Darwins moved to Down House in Kent.

What it contained: Many arguments that appear in the Origin, including the comparison between artificial and natural selection, are already in the sketch. It was a private document and was not published until 1909.

Why it matters: The core idea was on paper 17 years before the book.
28 Sep 1838

Reading Malthus gives Darwin the mechanism Private theory

LondonNotebook D

What happened: Darwin read Thomas Malthus’s Essay on the Principle of Population, which argued that populations grow faster than food supply. He saw that in nature this pressure would preserve favourable variations and destroy unfavourable ones.

The four ideas: Variation, inheritance, a struggle for existence, and unequal survival and reproduction. Put together, they made natural selection.

What came next: Darwin married Emma Wedgwood in January 1839, the year his Journal of Researches on the Beagle voyage was published. His long illness began around the same time.

Why it matters: From this point Darwin had a theory, not just a suspicion.
Jul 1837

Darwin opens his private species notebooks Private theory

LondonNotebook B

What happened: Back from the voyage and working through his collections with specialists, Darwin opened a notebook on the “transmutation of species”. By then the ornithologist John Gould had told him that the Galapagos mockingbirds belonged to several species and that his finches were a group of closely related species.

The tree: On one page Darwin wrote “I think” and drew a small branching diagram showing species descending from a common ancestor, the first sketch of a tree of life.

Why it matters: Darwin had become an evolutionist; he still needed a mechanism.
Charles Darwin's 1837 notebook sketch headed I think, his first tree diagram of species descent
“I think”: Darwin’s first tree of descent, drawn in Notebook B in 1837. Image: Charles Darwin, via Wikimedia Commons, public domain.
1831-1836

The voyage of HMS Beagle Early life & voyage

Plymouth to FalmouthFive years at sea

What happened: Darwin sailed from Plymouth on 27 December 1831 as a gentleman naturalist on the survey ship HMS Beagle under Captain Robert FitzRoy. The voyage lasted almost five years, most of it in South America, and returned to Falmouth on 2 October 1836.

What he saw: Fossils of giant extinct mammals in Argentina, related species replacing one another down the continent, earthquake-raised coastlines in Chile and, from September to October 1835, the Galapagos Islands, where the animals differed from island to island.

What it did not do: Darwin did not leave the Galapagos with a theory of evolution. The voyage supplied the observations; their meaning became clear only when he worked through the collections in London.

Why it matters: The voyage gave Darwin the questions. It took him years at home to answer them.
HMS Beagle in the Strait of Magellan, painted by Conrad Martens during the voyage
HMS Beagle in the Strait of Magellan, painted by the voyage artist Conrad Martens. Painting: Conrad Martens, via Wikimedia Commons, public domain.
12 Feb 1809

Charles Darwin is born Early life & voyage

The Mount, ShrewsburyBirth

What happened: Charles Robert Darwin was born at Shrewsbury in Shropshire, the fifth child of the doctor Robert Darwin and Susannah Wedgwood. He was born on the same day as Abraham Lincoln.

The family: His grandfather Erasmus Darwin had speculated about evolution in the 1790s, and his mother’s family were the Wedgwood potters. Charles studied medicine at Edinburgh and then prepared for the Church at Cambridge before the Beagle offer came.

Why it matters: His birthday is the date the world now marks as Darwin Day.
Charles Darwin photographed by Maull and Polyblank in 1855, while he was preparing his species theory
Charles Darwin in 1855, a year after he returned to the species question. Photo: Maull and Polyblank, via Wikimedia Commons, public domain.

Why Did Darwin Delay Publishing On the Origin of Species?

Seven connected reasons, from the evidence he wanted to the letter that ended the wait.

Chart of Charles Darwin's work from 1831 to 1859: the Beagle voyage, species notebooks, geology books, barnacles, the big book and the Origin
Darwin’s two decades were full: geology books, eight years on barnacles, then the unfinished big book. Chart by AiTimeline from the Darwin Correspondence Project and Darwin’s journal.

Darwin’s delay was the result of several connected factors. His letters and manuscripts show concern about evidence, scientific credibility, the scale of the work and the risk of publishing an incomplete argument. Historians still argue about how much weight each one carries.

1. He wanted overwhelming evidence

Claiming that species change challenged both scientific and religious assumptions. Darwin did not want to rest the case on a single observation, so he gathered evidence from many fields:

  • Domestic breeding and artificial selection, including pigeons he bred himself.
  • Fossils and the order in which they appear in the rocks.
  • The geographical distribution of species, especially on islands.
  • Similarities in anatomy and in embryos.
  • Variation within wild and domestic populations.
  • The relationships between living and extinct organisms.

2. He feared publishing an incomplete theory

Darwin repeatedly said that a short summary would be inadequate, because each major argument needed facts behind it. He was not waiting for a convenient moment; he was trying to write something that could withstand criticism from the best naturalists of the day.

3. He was busy with other research

Between 1838 and 1846 he wrote up the geology and zoology of the Beagle voyage. From 1846 to 1854 he worked on barnacles. These were not distractions so much as the work that made him an authority, and they gave him direct experience of variation and classification. Darwin even studied how coral reefs form, a question still at the heart of the modern coral reef crisis.

4. He was writing a much larger book

From May 1856 Darwin was writing a full treatise, Natural Selection. By June 1858 it ran to about a quarter of a million words and was only half done. Even when Wallace forced him to cut, the “abstract” became a book of more than 500 pages.

5. He knew the controversy his ideas would cause

In January 1844 Darwin told Joseph Hooker that admitting species were not immutable was “like confessing a murder”. He watched the attacks on Vestiges the same year, and he knew his wife Emma was distressed by his loss of faith. But it would be misleading to reduce the whole delay to fear: the documents point at least as strongly to scientific caution and the sheer amount of research still to do.

6. His health and family life slowed him

From the late 1830s Darwin suffered long bouts of illness that often limited him to a few hours’ work a day. He had ten children, three of whom died young, including Annie in 1851 and Charles Waring in June 1858. These help explain the pace of his work, though not the two decades on their own.

7. Wallace made the delay impossible

The most immediate reason Darwin published in 1858 and 1859 was Wallace’s essay. Another naturalist had independently reached the same explanation. Lyell and Hooker’s solution was a joint presentation, followed by Darwin’s book.

Bar chart of years from each Darwin milestone to the November 1859 publication of On the Origin of Species
From the idea of natural selection to the book took 21 years; from Wallace’s letter, 17 months. Chart by AiTimeline.
The historians’ debate

Was there really a “delay”?

For much of the 20th century, biographers described Darwin as a man who hid his theory for 20 years out of fear of scandal. In 2007 the historian John van Wyhe, director of Darwin Online, challenged this in a paper titled “Mind the gap”. He argued that Darwin told many friends about his views, never said he was delaying out of fear, and was following a plan to finish the barnacles and then the species book.

Most historians now take a middle position: Darwin’s caution was real, but so were his scientific reasons and his workload. The documents, rather than any single motive, are the best guide, and they show a theory that was always being worked on.

Every Version of the Theory, 1837–1859

Darwin’s early private writings, the joint presentation and the book were different documents with different readers.

VersionDateFormWho saw itWhat happened to it
Species notebooks1837-1839Private notebooks B to EDarwin onlyPublished in full only in the 20th century
Pencil sketchMay-June 1842About 35 pagesDarwin onlyPublished 1909
EssayCompleted July 1844Fair copy of roughly 230 pagesEmma Darwin; later HookerExtracts read 1 July 1858; full text 1909
Letter to Asa Gray5 September 1857Short abstract in a letterAsa GrayExtract read 1 July 1858
Natural Selection (big book)May 1856 – June 1858About 250,000 words, half finishedDarwin; parts to HookerAbandoned; published 1975
Linnean paper1 July 1858Extracts with Wallace’s essayLinnean SocietyPrinted 20 August 1858
On the Origin of SpeciesPublished November 1859502 pages of text, 14 chaptersThe public1,250 copies; six editions by 1872

Darwin and Alfred Russel Wallace: Who Discovered Natural Selection?

Two independent discoveries, one joint presentation.

Portrait of naturalist Alfred Russel Wallace in 1862
Alfred Russel Wallace in 1862, four years after his essay reached Darwin. Photo: unknown photographer, via Wikimedia Commons, public domain.

Darwin and Wallace developed the principle of evolution by natural selection independently. Darwin had worked on it since 1838 and had written private sketches, an essay and a letter to Asa Gray before Wallace’s paper reached him. Wallace developed his own explanation while collecting in the Malay Archipelago, after years of fieldwork in the Amazon and in Borneo.

Their routes overlapped in one striking way: both men credited Thomas Malthus’s essay on population with the decisive insight. Their circumstances did not. Darwin was a wealthy, established naturalist with powerful friends; Wallace was a professional collector paying for his travels by selling specimens. That difference is why some writers have questioned whether the 1858 arrangement was fair to Wallace, who was not asked in advance.

Wallace himself never complained. He was pleased to be presented alongside Darwin, defended natural selection for the rest of his life and called his 1889 book on the subject Darwinism. It is most accurate to describe natural selection as an idea independently discovered by both men, with Darwin’s 1859 book supplying the extended evidence that persuaded the scientific world.

Charles DarwinAlfred Russel Wallace
Born12 February 1809, Shrewsbury8 January 1823, Usk, Monmouthshire
Field experienceHMS Beagle, 1831-1836Amazon 1848-1852; Malay Archipelago 1854-1862
Reached natural selectionSeptember 1838, after reading MalthusFebruary 1858, after recalling Malthus during a fever
First written statement1842 sketch (private)1858 Ternate essay, sent to Darwin
Published accountLinnean paper 1858; the Origin 1859Linnean paper 1858; Darwinism 1889
Social standing in 1858Wealthy gentleman naturalist, Royal Medal winnerSelf-funded collector selling specimens

What Was Darwin’s Theory of Natural Selection?

Natural selection is the process by which inherited characteristics that improve an organism’s chances of surviving and reproducing become more common in a population over generations. It rests on four connected ideas:

1. VariationIndividuals in a population differ from one another.
2. InheritanceSome of those differences pass from parents to offspring.
3. StruggleMore are born than can survive; food, predators, disease and climate limit numbers.
4. Unequal reproductionIndividuals with helpful traits leave more offspring, so those traits spread.

Over many generations these differences change populations, and over longer periods they can produce new species. Darwin’s key analogy was with breeders: if farmers could transform pigeons, dogs and crops by choosing which animals and plants to breed, nature could do the same over far longer spans of time. Modern plant breeding, from the dwarf wheat of India’s Green Revolution onwards, is the same principle applied deliberately. Darwin did not know how inheritance worked; Mendel’s genetics, rediscovered in 1900, later supplied that missing piece.

HMS Beagle and the Galapagos Islands: Where the Questions Began

The five-year voyage of HMS Beagle took Darwin around South America, across the Pacific and home by way of Australia and the Cape of Good Hope. Most of his time was spent on land, collecting rocks, fossils, plants and animals. The five weeks in the Galapagos Islands in 1835 are the most famous part, but the fossils of the Argentine pampas and the way related species replaced each other along the continent mattered as much.

Darwin left the Galapagos without realising the importance of what he had collected. Only when specialists examined his specimens in London did the picture change: the islands’ mockingbirds were distinct species, and his finches turned out to be a whole group of related species. The finches later became the textbook example of adaptive radiation, thanks largely to long-term field studies in the 20th century.

Four Galapagos finches drawn by John Gould showing different beak shapes
Galapagos finches as drawn by John Gould, who first classified Darwin’s birds in 1837. Illustration: John Gould, via Wikimedia Commons, public domain.
Common mix-ups

Five things often told wrongly about Darwin and the Origin

  • “The book sold out on publication day.” All 1,250 copies were ordered by booksellers at Murray’s trade sale on 22 November 1859, two days before the official 24 November publication date.
  • “Darwin worked out evolution on the Galapagos.” He left the islands in October 1835 without a theory. It was the mockingbirds, and John Gould’s classification of the birds in London in 1837, that changed his mind.
  • “Darwin coined ‘survival of the fittest’.” Herbert Spencer did, in 1864. Darwin added it to the fifth edition in 1869.
  • “His eldest daughter was ill in June 1858.” The daughter with diphtheria was Henrietta, then 14. His eldest daughter, Annie, had died in 1851.
  • “Wallace’s paper was published and Darwin’s was not.” Both were read together on 1 July 1858 and printed together in August 1858.

Why Darwin Day Is Celebrated on 12 February

Darwin Day is observed every year on 12 February, the anniversary of Charles Darwin’s birth in 1809. It began as an informal celebration organised by scientists, humanist groups and universities, and is now marked by museums, schools and science societies in many countries with lectures, exhibitions and nature walks. It is not a public holiday.

The day celebrates scientific inquiry, evidence-based thinking and natural history. It is also a reminder of how scientific ideas actually develop: through observation, testing, debate, collaboration and revision, rather than a single flash of insight. The bicentenary of Darwin’s birth in 2009, which was also the 150th anniversary of the Origin, was marked around the world.

Darwin Day is not the anniversary of the book. The two dates mark different milestones:

  • 12 February 1809: birth of Charles Darwin, marked as Darwin Day.
  • 24 November 1859: publication of On the Origin of Species, sometimes marked as Evolution Day.

For other turning points in the history of science, see how Galvani and Volta made the first battery, the history of computing pi and the story of the Nobel Prizes. For the living world Darwin studied, see the discovery of the first adult T. rex trackway and India’s Project Tiger.

Explore More Timelines

People Also Ask

How long did Darwin wait to publish his theory?
About 21 years from the moment the idea took shape, in September 1838, to the book in November 1859. Measured from the first written sketch in 1842 the gap is 17 years, and from the long 1844 essay it is 15 years.
Was the Origin of Species published on Darwin Day?
No. Darwin Day, 12 February, is Darwin’s birthday. On the Origin of Species was published on 24 November 1859, which is sometimes marked as Evolution Day.
Did Wallace steal Darwin’s theory, or did Darwin steal Wallace’s?
Neither. Darwin’s 1842 sketch, 1844 essay and 1857 letter to Asa Gray prove his priority, and Wallace reached the idea independently. Wallace accepted the 1858 arrangement and later called his own book Darwinism.
Did Darwin discover evolution on the Galapagos Islands?
No. He collected specimens there in 1835, but recognised what they meant only in 1837 in London, after John Gould classified the birds. Natural selection came in 1838, after he read Malthus.
Why is Darwin’s 20-year delay controversial among historians?
Older accounts said Darwin hid his theory out of fear. Later historians, notably John van Wyhe, argue that the evidence shows a busy scientist following a plan, not a man paralysed by fear. Most accept that several reasons worked together.

Darwin Day and On the Origin of Species: Frequently Asked Questions

Why did Charles Darwin wait 20 years to publish his theory?
Darwin wanted overwhelming evidence and a complete argument, he spent years on other research including eight years on barnacles, and from 1856 he was writing a huge treatise rather than a short book. He also knew the idea would be controversial. Wallace’s essay in June 1858 made publication urgent.
When did Darwin first develop his theory of evolution by natural selection?
Darwin accepted that species change in 1837, and found the mechanism of natural selection in September 1838 after reading Malthus. He wrote a short pencil sketch in 1842 and a longer essay in 1844.
When was On the Origin of Species published?
It was published by John Murray in London with 24 November 1859 as the publication date. Copies were offered to booksellers at Murray’s trade sale on 22 November.
How many copies of the first edition were printed?
1,250. Booksellers’ orders at the trade sale on 22 November 1859 exceeded the printing by about 250 copies, so the first edition was fully taken up and a second edition of 3,000 copies followed in January 1860.
Did Darwin’s book sell out on the first day?
In effect, yes, but before publication day. The whole first printing was ordered by booksellers at Murray’s trade sale on 22 November 1859, two days before the official publication date.
Who was Alfred Russel Wallace?
A British naturalist and collector (1823-1913) who explored the Amazon and the Malay Archipelago. He independently conceived natural selection in February 1858 and later did pioneering work on the geography of animals, including the Wallace Line.
What was in Wallace’s 1858 essay?
It was titled On the Tendency of Varieties to Depart Indefinitely from the Original Type. It argued that in the struggle for existence the better adapted varieties survive and multiply, so that varieties can diverge permanently from the parent species. It was close to Darwin’s theory.
When did Darwin receive Wallace’s essay?
Darwin’s letter forwarding it to Charles Lyell is dated 18 June 1858, and that is the generally accepted date. A few historians have argued it arrived earlier, but the evidence for that is disputed.
What happened at the Linnean Society on 1 July 1858?
The secretary read extracts from Darwin’s 1844 essay and his 1857 letter to Asa Gray, followed by Wallace’s essay. Lyell and Hooker arranged the reading. Neither Darwin nor Wallace was present, and the papers were published in August 1858.
Why did neither Darwin nor Wallace attend the Linnean Society meeting?
Darwin’s infant son Charles Waring had died of scarlet fever on 28 June 1858, and the family was in mourning. Wallace was thousands of miles away in the Malay Archipelago and learned of the reading afterwards.
Did Darwin and Wallace discover natural selection together?
They discovered it independently, not together. Darwin had worked on it since 1838; Wallace reached it in 1858. Their papers were presented jointly, and both are recognised as co-discoverers of the principle.
Was Darwin afraid of religious opposition?
He knew the theory would offend many people, including his devout wife, and in 1844 he said admitting it felt like confessing a murder. But his letters show that the need for evidence and a complete argument mattered at least as much. Fear alone does not explain the delay.
What was Darwin’s big book?
A large treatise called Natural Selection that Darwin began on 14 May 1856. By June 1858 he had written about ten and a half chapters, around a quarter of a million words. It was never finished; part was later used in other books and the rest was published in 1975.
What was Darwin’s 1844 essay?
An expanded version of his 1842 sketch, roughly 230 pages in its fair copy. Darwin left instructions with his wife to have it published if he died. Extracts were read at the Linnean Society in 1858, and the full text was published in 1909.
What was Vestiges of the Natural History of Creation?
An anonymous best-selling book of October 1844 arguing that life developed by natural law. Its author was Robert Chambers. Scientists condemned its errors, which convinced Darwin that his own theory needed much stronger support.
What role did the Beagle voyage play?
The voyage of 1831 to 1836 gave Darwin the observations that made him question fixed species: fossils in South America, the distribution of related species and the island-to-island differences on the Galapagos. The theory itself came later, in London.
What did Darwin’s finches have to do with the theory?
Less than the popular story suggests. Darwin did not label most of his finches by island, and it was the Galapagos mockingbirds that first made him think about species changing. The finches became a famous example of adaptation later, through other scientists’ work.
What is natural selection?
The process by which inherited traits that help an organism survive and reproduce become more common in a population over generations. It depends on variation, inheritance, competition for limited resources and unequal reproduction.
Did Darwin use the phrase survival of the fittest?
Not at first. The phrase was coined by Herbert Spencer in 1864. Darwin adopted it as an alternative name for natural selection in the fifth edition of the Origin in 1869.
Did the word evolution appear in the first edition?
No. The first edition does not use the word evolution, although its last word is evolved. Darwin preferred the phrase descent with modification. Evolution was added in the sixth edition of 1872.
How did Darwin’s health affect his work?
From the late 1830s Darwin suffered long bouts of stomach upset, vomiting, fatigue and heart palpitations. He often could work only a few hours a day, and took water cures, including at Ilkley when the Origin was published.
What is Darwin Day?
An informal international celebration of science held each year on 12 February, Darwin’s birthday. Universities, museums and science groups hold lectures and events. It is not a public holiday in any country.
When did Darwin die?
Charles Darwin died at Down House on 19 April 1882, aged 73, and was buried in Westminster Abbey. Wallace was one of the pall-bearers at his funeral.

Conclusion: Darwin Waited for Evidence, but Wallace Changed the Timetable

Charles Darwin did not publish his theory as soon as he had it. He spent years examining specimens, comparing species, studying fossils and testing his explanation against everything he could think of. His private writings show that he had the central argument by 1842 and 1844, yet he kept gathering evidence because he believed an incomplete account would fail.

Alfred Russel Wallace’s essay in June 1858 turned a private research programme into a question of priority. Lyell and Hooker’s joint presentation acknowledged both naturalists, and 17 months later On the Origin of Species appeared. Darwin Day celebrates more than a famous birthday: it is a reminder that major discoveries are rarely instant, and that publishing them takes both evidence and nerve.

Title page of the 1859 first edition of On the Origin of Species by Charles Darwin, published by John Murray
Title page of the first edition, published by John Murray in November 1859. Image via Wikimedia Commons, public domain.

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⚠️ Editorial Note

Last updated 31 October 2026. Dates follow the Darwin Correspondence Project at Cambridge University Library, Darwin’s own journal and standard references. Where accounts differ we say so: for example, the 18 June 1858 arrival date of Wallace’s essay is accepted by most historians but has been disputed. Some popular summaries contain errors, which we correct in the “Common mix-ups” box. Quotations from Darwin’s letters keep his original abbreviations.

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