CHARLES ROBERT DARWIN  1809 - 1882

(G3a, G4, W4, Va, Vb, Vc)

Acknowledgements

Map (The World): licensed under Creative Commons. Author Sémhur – en.wikipedia.org/wiki/Charles_Darwin. Darwin: detail, watercolour by the English artist George Richmond (1809-1896), 1840, contained in Origins by Richard Leakey and Roger Lewin, published by Penguin Books, 1991 – English Heritage Photo Library, Downe House, Downe, Kent, England. Henslow: lithograph by the English engraver Thomas Herbert Maguire (1821-1895), 1851. Gray: 1867, artist unknown, contained in More Letters of Charles Darwin, a 2-volume work, published in 1903, sequel to The Life and Letters of Charles Darwin, edited by his son Francis in 1887. Huxley: detail, by the Scottish painter Malcolm Stewart (1829-1916) – Wellcome Library, London. Wallace: after a portrait by the artist Thomas Sims – National Portrait Gallery, London. Bates: detail, contained in obituary notice, Proceedings of the Royal Geographical Society and Monthly Record of Geography, April 1892, photographer unknown.

xxxxxAs we have seen, it was in 1831 (W4), as naturalist on board HMS Beagle, that the Englishman Charles Darwin began his five-year voyage around the world. It was a journey that was to produce his theory of “evolution” and - following the publication of his famous book The Origin of Species in 1859 - bring about a revolution in the science of biology, and a long period of bitter controversy in its wake.

xxxxxDarwin was born in Shrewsbury of quite a distinguished family. His father was a highly respected doctor and his mother, Susannah Wedgwood, was the daughter of the pottery designer and manufacturer Josiah Wedgwood. And he was also the grandson of Erasmus Darwin, the eminent physician and naturalist. He attended Shrewsbury School, but showed little interest in his lessons, spending much of his time collecting insects and pieces of rock. And later, as a medical student at Edinburgh, he proved unable to cope with the trauma of surgical operations and eventually left the course. However, during his two years in Scotland he made friends with various members of staff and cultivated a keen interest in geology and marine life.

xxxxxIn despair, his father, fearing that he would be a disgrace to the family, sent him to Cambridge to study for the priesthood. Again, he neglected his studies, spending many hours riding and hunting, but it was there, too, that he was able to devote even more time to his interest in geology and natural history. Hexlearnt a great deal from his close friend John Stevens Henslow, professor of botany, and on gaining his degree in 1831, he accompanied the distinguished professor of geology, Adam Sedgwick (1785-1873), on a three-week geological survey of North Wales. It was on the strength of this trip, together with Darwin’s enthusiastic interest in natural history, that Henslow managed to secure for him an unpaid post as the naturalist on board HMS Beagle, due to set sail on a scientific expedition in the December of that year. It was a five-year voyage that was to prove a decisive turning point in Darwin’s life, and to signal a momentous advance in man’s understanding of life on earth.

xxxxxThe scientific expedition was planned to take two years. In fact it lasted for five years and circumnavigated the globe via South America and the Pacific and Indian Oceans. Darwin was not a good sailor - he was frequently seasick - , but once on land he showed a remarkable capacity for hard work and meticulous study. During his arduous inland expeditions, some lasting more than a month, he made copious, carefully composed notes, and he sent back detailed information about his findings, together with geological and biological specimens.  

xxxxxIn his work as an amateur geologist he very quickly came out in favour of the argument put forward by the English geologist Charles Lyell in the early 1830s. This had maintained that the Earth’s surface had not been formed by sudden, short-lived explosions of great violence (the generally accepted “catastrophic theory”), but had been slowly changed in form over long periods of time by events such as erosion and earthquakes. At one of the expedition’s first points of call - the volcanic island of Sao Tiago in the Cape Verde islands (off the west coast of Senegal) - Darwin’s close study of the craters and the new lava spills firmly convinced him that the island’s entire surface had indeed been formed and shaped by a series of volcanic eruptions occurring over a vast period of time. Further research in South America - notably a study of the Andes - confirmed his view.

xxxxxThen later he put forward his own geological theory - substantiated by under water investigation in the 20th century.  Whilst studying the islands of the Pacific Ocean, he concluded that a circular coral atoll surrounding a lagoon was all that remained of a volcanic island which had slowly sunk into the sea and finally disappeared below the surface. On his return he made known his findings and conclusions in three books, published in the 1840s: Coral Reefs, Volcanic Islands, and Geological Observations on South America. These findings greatly enhanced his reputation in scientific circles and, at a later date, were to add support to some of his theories on evolution.

xxxxxHis refutation of the catastrophic theory met with strong opposition, but this was nothing compared to the condemnation that was to be heaped upon the ideas he developed in the field of natural history. His studies on the mainland of South America and on the islands of the South Pacific convinced him that, by means of a long, slow process of change, animals and plants had evolved from more primitive forms. He noticed that the fossils of extinct species that he discovered, though smaller in size, closely resembled living species within the same geographical environment, and during his period of detailed study on the Galapagos Islands, some 500 miles off the coast of Ecuador, he found ample evidence of this change or “mutation”. There he found living creatures, such as the tortoise, the marine iguana (illustrated), and the mockingbird, which showed variations in structure and feeding habits from one island to another, despite similar climatic and physical conditions. He demonstrated this “adaptation” by what came to be known as “Darwin’s Finches”. He showed, for example, that according to the food available, some seed-eating finches had more powerful beaks to crack open larger seeds, whilst others, living off local insects, had finer, pointed beaks.

xxxxxBut these findings were to raise even more fundamental issues. Were there possible links, Darwin began to ponder, between distinct but similar species? Indeed, by means of modifications taking place over a vast period of time, could species have evolved from other species? And In the long, fierce struggle for existence, had existing animals and plants survived because they had adapted more efficiently to their environmental conditions and passed these advantages on to their offspring or seeds? In the life of animals and plants, had the fittest survived and the weak become extinct by a process of “natural selection”?

xxxxxIt was with these questions in mind that Darwin returned home in 1836, but his theory about evolution - a theory which was to shock the world - was some time in the making, due to his fear of the consequences once they were made public, and to other more pressing work. He first settled in London to write a general account of his travels, published in 1839 under the title Journal of Researches into the Geology and Natural History of the Various Countries Visited by HMS Beagle (The Voyage of the Beagle), and it was during this period that he was elected to the Geographical Society and admitted to the Royal Society. In the meantime, he had set out his ideas on mutation in his Notebooks on the Transmutation of Species, - but keeping his more radical views to himself -, and by 1838 he had formulated an outline of his theory of evolution through natural selection. In this he was influenced by the predictions of Thomas Malthus on population, arguing that as animals were unable to produce more food for themselves, the battle for survival would be won by those species which best adapted to the changing conditions. Those that survived would perpetuate the race.

xxxxxIn 1839 Darwin married his cousin Emma Wedgwood, and three years later they settled at Downe House in Kent, just outside London. There, as a man of independent means, he was able to pursue his own topics of interest. He gave time to his theory of evolution, but he also worked on other natural history projects. Furthermore, his studies were hampered by a debilitating illness which he had caught, so it would seem, from the bites of a particular insect while researching in the pampas area of Argentina.

xxxxxIn 1842 he produced an outline of his theory for his friend Professor Henslow, but two years later he embarked on other work, including an eight-year study of barnacles. It was not until 1856, in fact, that Darwin began writing up his theory of evolution by natural selection. However, he doubled his efforts two years later when the young Welsh naturalist Alfred Russel Wallace sent him a memoir which contained a theory very similar to his own. Both men presented a joint paper before the Linnaean Society of London that year, and in November 1859 Darwin eventually published an abstract of his own theory under the title On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life.

xxxxx“The book that shook the world”, as it came to be called, was sold out on the first day of publication, and had gone through six editions by 1872. In the past, other scientists had hinted at the idea of organic evolution, including the French biologist Jean Baptiste de Lamarck and Darwin’s own grandfather Erasmus, but none had presented the case in such depth, order and clarity. As a result, it proved a theory that many rejected out of hand. The very idea that animals and plants had slowly developed from simple forms which had existed millions of years ago was clearly contrary to biblical teaching, which held that the world was formed in 4004 BC, and that all living things were specially created in their present form. God was the creator and designer.

xxxxxControversy over the theory raged across the western world. As one would expect, the most vociferous opposition came from the Church. At a meeting at Oxford University, for example, held in 1860, the Bishop of Oxford, publicly refuted “Darwinism” (as it came to be known), but came off the worse in an argument with the English biologist Thomas Henry Huxley, Darwin’s faithful “bulldog”. Less easy to answer, however, were the doubts of a number of sceptical scientists. Some questioned the mechanism whereby these variations or mutations were achieved and passed on, whilst others argued that the theory was based on flimsy evidence. And many harboured doubts about the theory well into the 20th century.

xxxxxAlthough Darwin all but avoided the sensitive issue of human evolution in his Origin of Species, his evolutionary theory begged the question and needed a fuller answer. As we shall see, he was to give that fuller answer twelve years later in his Descent of Man, published in 1871 (Vb), a work which attempted to throw light on the “origin of man and his history”, and promptly added fuel to a controversy which was already burning bright.

 

xxxxxIncidentally, in the formative years of his career Darwin was guided and encouraged by his older cousin William Darwin Fox, an entomologist, but it was the cleric-botanist John Stevens Henslow (1796-1861) (illustrated) who inspired him to take up a career in the natural sciences and got him his post on the Beagle. They became very good friends at Cambridge and, because of their daily walks together, Darwin became known as “the man who walks with Henslow”. ……

xxxxx……  Amongxthe critics of Darwin’s theory of natural selection was his one-time friend the English anatomist Richard Owen (1804-1892). In 1860 he wrote a long anonymous article condemning The Origin of Species and describing it as “extremely malignant”. Later, however, as director of the natural history museum in London, Owen introduced the term “dinosaur” (Greek for “terrible lizard”), and gave the first public exhibition of these extinct reptiles. ……

xxxxx……  Axfriend and firm supporter of Darwin was the leading American botanist Asa Gray (1810-1888) (illustrated). He was one of the founders of the American National Academy of Sciences, and his works included Elements of Botany, the Flora of North America, and his standard reference book Manual of Botany, published in 1850. Among Darwin’s other friends was Charles Babbage, the inventor of the first mechanical calculating machine, and the historian Thomas Carlyle.

xxxxxThe English biologist Thomas Henry Huxley (1825-1895) is best remembered today for his stout defence of Darwin’s theory of evolution, but he also made important contributions to science, notably in the fields of marine life and comparative anatomy. In addition, he introduced new systems of classification for both the bird and animal kingdoms. While serving as a surgeon on HMS Rattlesnake during the late 1840s, he made a special study of plankton and jellyfish, and in 1858 he was the first to disprove the theory that the skull originated from expanded vertebrae.

xxxxxHis series of lectures on organic evolution did much to win over public support for Darwin’s theory, but in the 1860s he himself courted controversy with his Zoological Evidence as to Man’s Place in Nature, a work in which he suggested that apes were the closest relatives of humans. In 1869 he coined the term “agnostic” to explain his own attitude to religion. The novelist Aldous Huxley and the biologist Julian Huxley were his grandsons.

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xxxxxIt was over a period of some ten years, 1848 to 1858, during expeditions to the Amazon and the Malay Archipelago, that the Welsh naturalist Alfred Russel Wallace (1823-1913) came up with his own theory of evolution based on natural selection. When in February 1858 he finally hit upon the idea of the “survival of the fittest”, he put his ideas together in the space of a few evenings and sent them to Darwin, then working on the final draft of his own ideas on the subject. On receiving Wallace’s data Darwin was astounded by the similarity in their findings. “I never saw a more striking coincidence” he wrote in a letter to the geologist Sir Charles Lyell. In July of that year Darwin and Wallace were able to present a joint paper to the Linnean Society in London, with Wallace’s contribution aptly entitled On the Tendency of Varieties to Depart Indefinitely from the Original Type. In all but small detail it could have been written by Darwin himself.

xxxxxIt was in February 1855, while working in Sarawak in Borneo, that Wallace wrote his essay On the Law Which Has Regulated the Introduction of New Species. During his research in both the Amazon region and in south-east Asia he had collected thousands of specimens and gathered a great deal of evidence on the variations within a given species. The animals which survived, he argued, were those which had a physical advantage, be it the length of talon in the case of the falcon, or the length of neck in the case of the giraffe. Likewise those species having colours which best aided their concealment were more likely to escape their predators. Thus “the weakest and least perfectly organized must always succumb.” It was indeed the survival of the fittest.

xxxxxHowever, The Origin of Species, published in November 1859, proved a more scholarly and detailed study of the subject, and it was thus Darwin who was awarded the bulk of the credit for introducing a theory which plunged the science of natural history into turmoil. For his part, Wallace worked to gain wider acceptance of their basic ideas in works such as Contributions to the Theory of Natural Selection, The Geographical Distribution of Animals, and Man’s Place in the Universe.

xxxxxIncidentally, while working in south-east Asia, Wallace divided the islands of the Malay Archipelago according to their zoological affinities. He classified the western islands of Borneo and Bali, for example, as Oriental, and the eastern islands, such as Celebes and Lombok, as Australian. The hypothetical line which divides these two groups is known to this day as “Wallace’s Line”. ……

xxxxx……  The phrase “survival of the fittest” was not coined by either Wallace or Darwin, but was first introduced by the English philosopher Herbert Spencer after reading On the Origin of Species. In his Principles of Biology of 1864 he wrote: “This survival of the fittest, which I have sought to express in mechanical terms, is that which Mr Darwin has called ‘natural selection’ or the preservation of favoured races in the struggle for life.” ……

xxxxx……  Darwin did in fact use the term in a latter edition of On the Origin of Species, but it did not find favour amongst later biologists because survival itself was only seen as a part of the complex notion of natural selection, and thus tended to distort Darwin’s theory. However, as we shall see, Spencer’s System of Synthetic Philosophy, made up of nine volumes and written over thirty years, brought him international recognition during the 1870s and early 1880s.

xxxxxOn his expedition to the Amazon region Wallace was accompanied by his friend the English naturalist Henry Bates (1825-1892). He was born and grew up in Leicester and it was there that he came to know Wallace when the Welshman was teaching at the Collegiate School in the city. They were both firm believers in evolution by natural selection, and in 1848 set out for the Amazon rainforests “to gather facts towards solving the problem of the origin of species”. They worked independently and, over the next eleven years, Bates made a detailed study of insect life over a large area, sending back home some 14,000 specimens, the majority of which were then unknown to science. From 1864 he worked as the assistant secretary of the Royal Geographical Society, and he served twice as the president of the Entomological Society in London. He wrote a scholarly account of his work in Brazil in his The Naturalist on the River Amazons of 1863, and for his contribution to natural science he was elected a fellow of the Royal Society in 1881. The bulk of his collection of specimens is to be seen in the Natural History Museum in London.