Table of contents |
2 Journey on the Beagle 3 First writings 4 The Origin of Species 5 Before Darwin 6 Darwin's theory of evolution 7 Views on religion 8 See also 9 External links |
Charles Darwin was born in Shrewsbury, Shropshire, England, the fifth of six children of Robert and Susannah Darwin (née Wedgwood), and the grandson of Erasmus Darwin, and of Josiah Wedgwood.
After finishing school, Darwin studied medicine in Edinburgh in 1825.
His dislike for dissection and the brutality of surgery at the time led him to leave the medical school in 1827.
Whilst there, however, he was influenced by the Lamarckian Robert Edmund Grant.
His father, unhappy that his younger son had not become a physician and fearing that he would become a "ne'er do well", enrolled him at Cambridge University, with the hopes of Charles' eventually becoming a parson.
While at Cambridge, he came under the intellectual influence of scientific minds such as William Whewell and John Stevens Henslow which (combined with his interest in collecting beetles, which was encouraged by his cousin, William Darwin Fox) resulted in him pursuing natural history.
After taking his degree with honors, Darwin stayed at Cambridge for further studies in geology, where he proved particularly adept. In the summer of 1831, Darwin worked with the great geologist Adam Sedgwick mapping strata in Wales.
Darwin had planned to visit Madeira with some class-mates upon graduation in 1831. These plans, however, fell through. After Darwin finished his studies, Henslow recommended him for the position of gentleman's companion to Robert Fitzroy, the captain of the HMS Beagle, which was departing on a five-year expedition to chart the coastline of South America.
Darwin's work during the Beagle expedition allowed him to study both the geological properties of continents and isles and a multitude of living organisms and fossils. He collected an enormous number of specimens new to science in a very methodical way, and his specimens sent back to the British Museum were by themselves a significant contribution to science, and made him one of the precursors of ecology. No other collector has rivalled his work since.
During his voyage, he visited the Cape Verde Archipelago, the Falkland Islands, the South American coast, the Galapagos Islands, New Zealand and Australia, collecting considerable quantities of specimens.
After returning from the voyage on October 2, 1836, Darwin analyzed the specimens he collected, and noticed similarities between fossils and living species within the same geographic area. In particular, he noticed that every island in the Galapagos Archipelago had its own kind of tortoises and birds that were all slightly different in appearance, favored food etc., but otherwise similar.
In the spring of 1837 ornithologists at the British Museum informed Darwin that the several very different species of birds he had taken in the Galapagos were all finches. This, coupled with a re-reading of Thomas Malthus' 1798 essay on populations, triggered a chain of thought that would culminate in the theory of evolution by natural and sexual selection.
He developed the hypothesis that, for example, all the different turtles had originated from a single turtle species, and had adapted to life on the different islands in different ways.
Based on these thoughts, he formulated his ideas about the changes and developments of species in his Notebook on the Transmutation of Species, which was in accordance with Lyell's Principles of Geology and Thomas Malthus' Essay on the Principle of Population, which stated that the size of a population is limited by the food resources available.
Realizing the potential of this understanding, Darwin undertook extensive experiments with pigeons and plants, and extensive consultation with pig breeders and other animal husbanders, in an attempt to discover holes in the hypothesis.
In 1842, Darwin formulated a short "Pencil Sketch" of his theory and by 1844 had written a 240 page "Essay" which provides an expanded version of his early ideas on natural selection.
Between 1844 and 1858, when he would present his theory to the Linnean Society of London, Darwin would modify his theory in a number of ways.
Darwin published other treatises in science, including an explanation for the creation of coral atolls in the South Pacific, and the story of his voyage aboard the Beagle.
Darwin married his cousin Emma Wedgwood in 1839.
After living for a number of years in London, the couple eventually moved to Down House, in Downe, Kent (which is now open to public visits, south of Orpington).
Darwin and his wife had ten children, three of whom died early. Between 1839 and 1843, Darwin's Zoology of the Voyage of H.M.S. Beagle was published in five volumes.
Darwin's work brought him a correspondence relationship with Alfred Russel Wallace, working in the islands of the South Pacific. In June, 1858, Wallace sought Darwin's ideas on a theory Wallace had developed which exactly mirrored Darwin's own work. Scientist friends persuaded Darwin to go public with the theory, now independently confirmed. On 1 July, 1858, Darwin's paper about The Origin of Species by Means of Natural Selection was read to the Linnean Society in London, jointly with Wallace's paper.
Darwin's book On the Origin of Species by Means of Natural Selection was published one year later, and was of sufficient interest to have the publisher's stocks completely sold to bookstores on the first day.
It provoked an outraged response from the Church. A large meeting was organised in Oxford where 'Soapy Sam' Wilberforce, the Bishop of Oxford, numerous Clergy and Robert Fitzroy (the Captain of HMS Beagle) argued against Darwin, Thomas Huxley and their Evolutionist supporters. On being asked by Wilberforce, whether he was descended from monkeys on his grandfather's side or his grandmother's side, Huxley, recognizing the stupidity of the question, apparently muttered to himself: "The lord has delivered him into my hands", and then replied that he "would rather be descended from an ape than from a cultivated man who used his gifts of culture and eloquence in the service of prejudice and falsehood" [several alternative versions of this supposed quote exist, see Wilberforce and Huxley: A Legendary Encounter.
In several of his later books
The Variation of Animals and Plants Under Domestication (1868),
The Descent of Man, and Selection in Relation to Sex (1871) and
The Expression of Emotions in Animals and Man (1872),
Darwin expanded on many topics introduced in
Origin of Species.
The value of Darwin's work was appreciated throughout the scientific community.
He became a member of the Royal Society of London in 1839 (on the basis of his collecting during his voyages) and of the French Academy of Sciences (l'Académie des Sciences) in 1878
Darwin died in Downe, Kent, England, on 19 April 1882 was given a state funeral, and interred in Westminster Abbey near Isaac Newton.
Darwin was given particular recognition in 2000 when his image appeared on the Bank of England ten pound note, replacing Charles Dickens. His impressive and supposedly hard-to-forge beard was reportedly a contributing factor in this choice.
Before the nineteenth century, the accepted theory for the extinction of species was called Catastrophism, which stated that species went extinct due to catastrophes that were often followed by the formation of new species ex nihilo (out of nothing).
The extinct species can then be found as fossils.
The new species were considered unchangeable.
This theory was in accordance with the story of the Flood in the Bible.
In the early nineteenth century, several new theories started to compete with Catastrophism.
One of the most important ones was developed by Jean-Baptiste Lamarck (1744-1829).
He observed that every new generation inherits the traits of its ancestors.
He suggested that traits or organs become enhanced with repeated use and weakened or removed by disuse in each individual, who will pass these improvements or losses directly to their offspring.
In 1830, the British geologist Sir Charles Lyell disproved the Catastrophism Theory, but held on to the theory of species staying unchanged during time.
Lyell founded uniformitarianism, a theory stating that the surface of earth changed slowly through eons by constant forces.
Darwin's theory of evolution is based on five key observations and inferences drawn from them. These observations and inferences have been summarized by the great biologist Ernst Mayr as follows: First, species have great fertility. They make more offspring than can grow to adulthood. Second, populations remain roughly the same size, with modest fluctuations. Third, food resources are limited, but are relatively constant most of the time. From these three observations it may be inferred that in such an environment there will be a struggle for survival among individuals. Fourth, in sexually reproducing species, generally no two individuals are identical. Variation is rampant. And fifth, much of this variation is heritable. From this it may be inferred: In a world of stable populations where each individual must struggle to survive, those with the "best" characteristics will be more likely to survive, and those desirable traits will be passed to their offspring. These advantageous characteristics are inherited by following generations, becoming dominant among the population through time (Fig. 2). This is natural selection. It may be further inferred that natural selection, if carried far enough, makes changes in a population, eventually leading to new species. These observations have been amply demonstrated in biology, and even fossils demonstrate the veracity of these observations.
Darwin imagined it might be possible that all life is descended from an original species from ancient times. DNA evidence supports this idea.
After the publication of Darwin's book, evolution as the means of natural selection was widely discussed (Fig. 3), particularly by the religious and the scientific communities.
Though Darwin was supported by some scientists (e.g., T.H. Huxley), others hesitated to accept the theory due to the unexplained ability of individuals to pass their special abilities to their offspring.
The last point remained a mystery until the existence of genes was discovered.
In 1902 Peter Kropotkin published the book Mutual Aid: A Factor of Evolution, challenging Darwin's Theory as too narrow.
In 1874, the theologian Charles Hodge accused Darwin of denying the existence of God by defining humans to be a result of a natural process rather than a creation designed by God. Darwin's theory is now backed up by the comparison of DNA from different organisms which shows the closeness of their relationship.
Today, whilst the overwhelming majority of biologists consider Darwin's basic theory correct, a significant fraction of the general population, particularly in the United States amongst Western countries, do not do so on religious grounds. See Pseudoscience creationism.
Contrary to popular opinion, Darwin did not "discover" evolution as it was accepted by many since the beginning of the 1800s.
Instead, he and Wallace discovered the first really coherent mechanism that explains how evolution occurs (natural selection).
Darwin is included in the top 10 of the 100 Greatest Britons poll sponsored by the BBC and voted for by the public.
It has been falsely claimed that Darwin converted to Christianity on his deathbed. The claim can be dismissed by his never having renounced the church.
This claim is discussed in The Survival of Charles Darwin: A Biography of a Man and an Idea, by Ronald W. Clark (Weidenfeld & Nicholson 1985), p. 199:
Early life
Journey on the Beagle
First writings
The Origin of Species
Before Darwin
Darwin's theory of evolution
Figure 2 : Schematic drawing of the evolution process.
(1) Natural selection. (2) Reproduction. (3) Mutation.
Response to Darwin's theory
Other important aspects of Darwin's overall theory were: common descent, sexual selection, gradualism, and pangenesis.
It is important to remember that Darwin's version of natural selection was different from that presented by Wallace in that he held that natural selection was continuously operating, whereas Wallace argued that selection only occurred when the environment changed.
Figure 3 : Caricature of Darwin as an ape in the Hornet magazine. (Image in the PD)
Views on religion
In the introduction of The Descent of Man (1871), Darwin wrote:
Later on in the book he dismisses an argument for religion being innate:
Darwin's own struggle with faith got sharper the older he became, and his posthumously-published autobiography contained quotes about Christianity that were omitted by Darwin's wife Emma and his son Francis because they were deemed dangerous for Charles Darwin's reputation.
Only in 1958 Darwin's granddaughter Nora Barlow published a revised version which contained the omissions.
This included statements such as:See also
External links
'Expression of Emotions in Man and Animals' http://paradigm.soci.brocku.ca/~lward/Darwin/darwin00.html