English Naturalist, Scientist, and Philosopher. He is best remembered for his book "On the Origin of Species," published in 1859, that established all species of life have descended over time from common ancestors, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection, in which the struggle for existence has a similar effect to the artificial selection involved in selective breeding. While controversial, due to its departure from the religious view of creationism, by the 1870s the scientific community and much of the general public had accepted evolution as a fact. He was born the fifth of six children in Shrewsbury, Shropshire, England at his family home, The Mount. His father was a wealthy society doctor and financier, and both sides of his family were Unitarians. In July 1818, when he was eight years old, his mother died and the following September he attended the Anglican Shrewsbury School with his older brother Erasmus as a boarder. He spent the summer of 1825 as an apprentice doctor, helping his father treat the poor of Shropshire, before going to the University of Edinburgh Medical School in October of that year, which at the time was the best medical school in Scotland. He found lectures dull and surgery distressing, so neglected his studies and turned his attention to nature. Which he found more fascinating. In 1826 he joined the Plinian Society, a student natural history group whose debates strayed into radical materialism. He assisted Robert Edmond Grant's investigations of the anatomy and life cycle of marine invertebrates in the Firth of Forth, Scotland, and in March 1827 presented at the Plinian his own discovery that black spores found in oyster shells were the eggs of a skate leech. The neglect of his medical studies annoyed his father, who sent him to Christ's College in Cambridge, England, for a Bachelor of Arts degree as the first step towards becoming an Anglican minister. He was unqualified for the Tripos, so he joined the ordinary degree course in January 1828. His cousin William Darwin Fox introduced him to the popular craze for beetle collecting, which he pursued zealously, getting some of his finds published in Stevens' "Illustrations of British Entomology." He became a close friend and follower of botany professor John Stevens Henslow and met other leading naturalists who saw scientific work as religious natural theology, becoming known as "the man who walks with Henslow". When his own exams drew near, he focused on his studies and was delighted by the language and logic of William Paley's "Evidences of Christianity." In his final examination in January 1831, he did well, coming tenth out of 178 candidates for the ordinary degree. He remained at Cambridge until June 1831, studying books on natural philosophy. In August 1831 he received a letter from Henslow, proposing him as a suitable gentleman naturalist for a self-funded temporary place on the HMS Beagle with Captain Robert FitzRoy, more as a companion than a mere collector. The ship was to leave in four weeks on an expedition to chart the coastline of South America. His father objected to his son's planned two-year voyage, regarding it as a waste of time, but was persuaded by his brother-in-law, Josiah Wedgwood, to agree to (and fund) his son's participation. After delays, the voyage finally departed Plymouth, England on December 27, 1831 and lasted almost five years. He spent most of that time on land investigating geology and making natural history collections, while the Beagle surveyed and charted coasts. He kept careful notes of his observations and theoretical speculations, and at intervals during the voyage his specimens were sent to Cambridge together with letters including a copy of his journal for his family. He had some expertise in geology, beetle collecting and dissecting marine invertebrates, but in all other areas was a novice and ably collected specimens for expert appraisal. Despite suffering badly from seasickness, he wrote copious notes while on board the ship. When they reached Brazil, he was enthused by the tropical forest, but detested the sight of slavery. At Bahia Blanca, Argentina, and in cliffs near Punta Alta, he made a major find of fossil bones of huge extinct mammals beside modern seashells, indicating recent extinction with no signs of change in climate or catastrophe. He identified the little known Megatherium by a tooth and its association with bony armor which had at first seemed to him like a giant version of the armor on local armadillos. In Chile, he experienced an earthquake and observed signs that the land had just been raised, including mussel-beds stranded above high tide. High in the Andes Mountains, he saw seashells and several fossil trees that had grown on a sand beach, and theorized that as the land rose, oceanic islands sank, and coral reefs round them grew to form atolls. On the Galápagos Islands, he searched for evidence attaching wildlife to an older "center of creation", and found mockingbirds allied to those in Chile but differing from island to island. He heard that slight variations in the shape of tortoise shells showed which island they came from, but failed to collect them, even after eating tortoises taken on board as food. In Australia, the marsupial rat-kangaroo and the platypus seemed so unusual that he thought it was almost as though two distinct Creators had been at work. He found the indigenous people (Aborigines) "good-humored & pleasant", and noted their depletion as a result of European settlement. The Beagle investigated how the atolls of the Cocos (Keeling) Islands had formed, and the survey supported Darwin's theories. FitzRoy began writing the official "Narrative of the Beagle' voyages, and after reading Darwin's diary he proposed incorporating it into the account. His "Journal" was eventually rewritten as a separate third volume, on natural history. While at Cape Town, South Africa, he met John Herschel, who had recently written to English geologist Charles Lyell, praising his uniformitarianism as opening bold speculation on "that mystery of mysteries, the replacement of extinct species by others" as "a natural in contradistinction to a miraculous process". When organizing his notes as the ship sailed home, he wrote that if his growing suspicions about the mockingbirds, the tortoises and the Falkland Islands fox were correct, "such facts undermine the stability of Species", then cautiously added "would" before "undermine". He later wrote that such facts "seemed to me to throw some light on the origin of species". When the Beagle finally reached Falmouth, in Cornwall, England on October 2, 1836, he was already a celebrity in scientific circles as in the previous December, Henslow had fostered Darwin's reputation by giving selected naturalists a pamphlet of his geological letters. He visited Henslow at Cambridge, who advised on finding naturalists available to catalogue the collections and agreed to take on the botanical specimens. His father organized investments, enabling his son to be a self-funded gentleman scientist, and he made the rounds of the London institutions, being honored and seeking experts to describe the collections. In December 1836 he took up residence at Cambridge to organize work on his collections and rewrite his "Journal." 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 January 4, 1837. That same day, he presented his mammal and bird specimens to the Zoological Society. The ornithologist John Gould soon announced that the Galapagos birds that Darwin had thought a mixture of blackbirds, "gros-beaks" and finches, were, in fact, twelve separate species of finches. On February 17, 1837 he was elected to the Council of the Geological Society, and Lyell's presidential address presented Owen's findings on Darwin's fossils, stressing geographical continuity of species as supporting his uniformitarian ideas. While rewriting his "Journal," he took on editing and publishing the expert reports on his collections, and with Henslow's help obtained a Treasury grant to sponsor this multi-volume "Zoology of the Voyage of H.M.S. Beagle." He stretched the funding to include his planned books on geology, and agreed unrealistic dates with the publisher. As a result of the stress from his work, his health suffered from the pressure and in September 1837 he had "an uncomfortable palpitation of the heart," so his doctors urged him to quit working and live in the country for a few weeks and get some much-needed rest before resuming his work. In March 1838 he reluctantly accepted the post of Secretary of the Geological Society. The continued strain of writing and editing his Beagle reports again took its toll on his health and in June 1838 he was laid up for days with stomach and heart problems and headaches, which would plague him for the remainder of his life. The cause of his illness remained unknown, and attempts at treatment had little success. In November 1838 he proposed marriage to his first cousin, Emma Wedgewood at her home, Maer Hall, whom he had met the previous year while recuperating from his first bout of illness. She accepted and they were married there on January 29, 1839 and moved to their new home in London, England, and they would have ten children, two of whom died in infancy. Five days prior to their wedding, he was elected as a Fellow of the Royal Society of London. In May 1839, FitzRoy's "Narrative" was published which included Darwin's "Journal and Remarks" as its third volume," and it was such a success that later in the year it was published on its own. Early in 1842, he wrote about his ideas of natural selection to Lyell, who noted that his ally "denies seeing a beginning to each crop of species. His book, "The Structure and Distribution of Coral Reefs" on his theory of atoll formation was published in May 1842 after more than three years of work, and he then wrote his first "pencil sketch" of his theory of natural selection. To escape the pressures of London, the family moved to rural Down House at Downe, Kent, England in September of that year. In 1846 he completed his third geological book. In 1849, in an attempt to improve his chronic ill health, he went to Dr. James Gully's Malvern spa and was surprised to find some benefit from hydrotherapy. In 1851 his treasured oldest daughter Annie became sick, reawakening his fears that his own condition might be hereditary, and after an extended illness she died. In November 1859 his "On the Origin of Species" went on sale and it proved unexpectedly popular, with the entire stock of 1,250 copies oversubscribed. In the book, he set out "one long argument" of detailed observations, inferences and consideration of anticipated objections. His only allusion to human evolution was the understatement that "light will be thrown on the origin of man and his history". The book aroused international interest, with less controversy than had greeted Scottish journalist Robert Chambers' popular "Vestiges of the Natural History of Creation." The Church of England's response was mixed, with his old Cambridge tutors, Sedgwick and Henslow, dismissing the ideas, but liberal clergymen interpreted natural selection as an instrument of God's design. His close friends still expressed their various reservations but gave strong support, as did many others, particularly the younger naturalists. Darwinism soon became a movement covering a wide range of evolutionary ideas. In 1863 Lyell's "Geological Evidences of the Antiquity of Man" popularized prehistory, though his caution on evolution disappointed Darwin. Weeks later, Huxley's "Evidence as to Man's Place in Nature" showed that anatomically, humans are apes, then "The Naturalist on the River Amazons" by Henry Walter Bates provided empirical evidence of natural selection. Through intense lobbying, on November 3, 1864 Darwin was awarded England's highest scientific honor, the Royal Society's Copley Medal. Despite repeated bouts of illness during the last twenty-two years of his life, his work continued. Having published "On the Origin of Species" as an abstract of his theory, he pressed on with experiments, research, and writing of his "big book". He covered human descent from earlier animals including evolution of society and of mental abilities, as well as explaining decorative beauty in wildlife and diversifying into innovative plant studies. His 1868 "The Variation of Animals and Plants Under Domestication" was the first part of his planned "big book," and included his unsuccessful hypothesis of pangenesis attempting to explain heredity. It sold briskly at first, despite its size, and was translated into many languages. He wrote most of a second part, on natural selection, but it remained unpublished in his lifetime. In 1871 he published "The Descent of Man, and Selection in Relation to Sex" providing evidence from numerous sources that humans are animals, showing continuity of physical and mental attributes, and presented sexual selection to explain impractical animal features such as the peacock's plumage as well as human evolution of culture, differences between sexes, and physical and cultural racial characteristics, while emphasizing that humans are all one species. His research using images was expanded in his 1872 book "The Expression of the Emotions in Man and Animals," one of the first books to feature printed photographs, which discussed the evolution of human psychology and its continuity with the behavior of animals. Both books proved very popular, and he was pleased by the general assent with which his views had been received. His evolution-related experiments and investigations led to the books "Insectivorous Plants" (1875), "The Effects of Cross and Self Fertilization in the Vegetable Kingdom" (1876), "The Power of Movement in Plants" (1880), and "The Formation of Vegetable Mould through the Action of Worms" (1881). In 1882 he was diagnosed with what was called "angina pectoris" which then meant coronary thrombosis and disease of the heart. He died at his Down House residence at the age of 73. He had expected to be buried in St Mary's Churchyard at Downe, but at the request of his colleagues, after public and parliamentary petitioning, William Spottiswoode (President of the Royal Society) arranged for him to be interred at Westminster Abbey, in London, close to Sir John Herschel and Sir Isaac Newton. During his lifetime, many geographical features were given his name. An expanse of water adjoining the Beagle Channel near the southern tip of South America was named Darwin Sound. Mount Darwin in the Andes Mountains was named in celebration of his 25th birthday. When the Beagle was surveying Australia in 1839, his friend John Lort Stokes, sighted a natural harbor which the ship's captain Wickham named Port Darwin. A nearby settlement was renamed Darwin in 1911, and it became the capital city of Australia's Northern Territory. More than 120 species and nine genera have been named after him. Additionally, his work has continued to be celebrated by numerous publications and events. The Linnean Society of London has commemorated Darwin's achievements by the award of the Darwin-Wallace Medal since 1908. Darwin Day has become an annual celebration, and in 2009 worldwide events were arranged for the bicentenary of Darwin's birth and the 150th anniversary of the publication of On the Origin of Species. He is commemorated in England, with his portrait printed on the reverse of £10 banknotes printed along with a hummingbird and HMS Beagle, issued by the Bank of England. A life size seated statue of him is located in the main hall of the Natural History Museum in London. A seated statue of him stands in front of Shrewsbury Library, the building that used to house Shrewsbury School, which he attended as a boy. Darwin College, a postgraduate college at Cambridge University, is named after the Darwin family.