October 2, 2009 BIOE 109 Fall 2009 Lecture 4 The life of Charles Darwin References: A. Desmond and J. Moore 1991. Darwin. Penguin. J. Browne. 1995. Charles Darwin: Voyaging. Random House. J. Browne. 2002. The Power of Place. Random House. The early years - Darwin was born on February 12th 1809 in Shrewsbury, Shropshire, England the second son and fifth of six children born to Dr. Robert Darwin, a prominent local physician. - Darwin s father, Robert Darwin, was a very successful physician. - his mother, Susanna, was a daughter of Josiah Wedgwood - the founder of the Wedgwood china empire. - the family was not lacking for money - the Wedgwoods were much wealthier than the Darwins. - however, Robert Darwin was a very astute financier, a kind of private lending institution, who garnered an immense fortune that freed Charles (and the rest of the family) from ever having to worry about money or work for a living. - Robert Darwin practiced medicine less and less over time, given the success he enjoyed in investing. - he was a large man (6 2 ) and stopped weighing himself after he reached 24 stone (336 lbs.) in weight. - he was so large that he required his coachman to test the strength of floorboards in the homes he visited. - he also had special stone steps made for him to enter his carriage! - by the time he died, he had left an estate worth 223,759 pounds. - Darwin s early performance at school was quite ordinary - later in life he admitted I must have been a very simple little fellow. - Charles idolized his older brother Erasmus who was almost five years his elder. - Erasmus was to play an important role in Charles personal and intellectual life. - as young children and up until their time at the University of Edinburgh, Charles and Erasmus were close friends who shared very similar interests. - like many boys raised in rural England, Darwin s early interests were based entirely on outdoor activities. - he learned to ride ponies, to fish, and to shoot. - he pursued natural history with total absorption. - Charles was an avid collector from a very early age, collecting all kinds of natural or antiquarian objects.
- he collected insects, bird eggs, pebbles, and even the wax seals that came on letters. - this passion for collecting items was instilled early and remained a passion for the rest of his life. - not only was Charles an avid collector, he was also meticulous in recording details of these items. - the habit of recording detail served Darwin well throughout his career - particularly during the Beagle voyage. - Darwin s mother died when he was eight - from what is now thought to be appendicitis - and he was largely raised from that point on by his three older sisters. Shrewsbury School (1818-1825) - a few months after his mother died, at the age of 9, Charles was sent away to board at Shrewsbury school located in the center of town. - Shrewsbury school was an upper class boarding school whose main aim was to prepare young gentlemen for entry into Oxford or Cambridge. - Darwin loathed the experience. - the curriculum was strictly classics with a little history and geography thrown in. - Charles grew closer than ever to his older brother Erasmus, who was attending the same school. - Erasmus was developing a keen interest in chemistry, and Charles began to like the subject through his enthusiasm. - the two boys set up a lab in an old washing room, or scullery, in the back garden of The Mount (the name of their home). - they would experiment in analyzing interesting minerals or the metallic residues of coins. - in these early experiments that we see the first beginnings of experimental science that Charles was to maintain throughout his career. - Charles performance at Shrewsbury was not good enough to gain him entry into Oxford or Cambridge. - Darwin s poor performance at Shrewsbury school must have been disappointing for his father. - it was decided by his father that Charles would become a physician, like himself, and thus continue the family tradition. The University of Edinburgh (1825-1827) - in the fall of 1825, Charles joined his older brother Erasmus at the University of Edinburgh who had begun his studies there a year earlier. - the move to Edinburgh must have been a shock to the two boys. - the University itself was only half-built at this time and, coupled with the deteriorating urban life, contrasted sharply with their upbringing in a quiet respectable town. - the classes were quite a contrast to what they were used to. - rowdy classes were normal in medical school - the students sang, shouted, stamped their feet and scraped their benches as signs of disapproval during lectures. - trumpets and peashooters were common.
- Never come into the class until after the hour advised a student magazine in 1825, and when you do come, make as great a noise as you can in opening the door and going for your seat, for it shows you are there, and lets your acquaintances know where to find you when the class is over. - Charles hated medical school. - the site of blood made him squeamish, and he particularly disliked the series of lectures on anatomy given by Alexander Munro. - the practicals (lab sessions) in Munro s class were particularly revolting to Darwin. - these were performed in a huge new amphitheater with steeply tiered benches by a Prosector. - during the session, one or two cadavers were displayed and dissected. - Darwin s dislike of dissection was intensified by the notorious traffic in corpses at that time in Edinburgh. - the trade in bodies had a long history and was fueled by the medical school. - cadavers were smuggled in from Dublin in kegs of whisky, or up from the slums of London. - many were illegally supplied by grave robbers. - the year after Darwin left, an Irishman named William Burke, was tried and convicted of murdering at least 16 people and delivering them to the back door of the medical school in the middle of the night. - he was paid 8 pounds per body in the summer and 10 pounds in the winter (reflecting the quality of the cadavers). - Darwin did enjoy taking courses by Robert Jameson on natural history and became close friends with Robert Grant, who was then teaching invertebrate biology. - it was through Grant that Darwin got a heavy dose of Lamarkian evolutionary theory - although it was clear that it had little long-lasting effect on Charles. - after two years at Edinburgh, it was decided by his father that Charles would attend the University of Cambridge to study to become a minister. - this was the most avenue that best offered Charles the chance to continue his studies of natural history. Cambridge University (1828-1831) - Darwin arrived in Cambridge in January of 1828. - he received his BA in 1831 after a tedious curriculum of classics, theology and mathematics. - he finished tenth in his class of 178 students. - his performance was very good considering that most of his Cambridge days were spent fox hunting, riding, shooting, or at his favorite pastime of all - collecting beetles. - at Cambridge, Darwin met John Stevens Henslow - then a professor of Botany - who was to prove to be the most influential figure in Darwin s early career. - the other person who was to greatly influence Darwin was Adam Sedgewick, a professor of Geology. - a particularly important event for Darwin was a field trip to north Wales with Sedgewick. - here, Darwin was taught important lessons in field geology that were to be put to good use later in South America.
- in August of 1831, after Darwin had completed his degree, a letter arrived at the Mount from Henslow who had been asked to recommend a suitable young man interested in science and natural history to join the voyage of a surveying ship called the H.M.S. Beagle. - Darwin was not to be brought on board as the ship s naturalist, but as a gentleman companion for the captain, Robert Fitzroy. - this was not than unusual a request - Fitzroy came from an aristocratic background and wanted desperately to have a dining companion on board who was an equal (the captain could not dine or converse with any of the ship s crew). - the idea of this voyage was not received kindly by Charles father. - however, he left Charles an opportunity of changing his mind by saying to his son: If you can find a man of common sense who advises you to go, then I will give my consent. - Charles knew instantly who he meant - his uncle Josiah Wedgwood. - Darwin quickly went to visit his uncle and together they formed a strategy of how best to approach Darwin s father to get him to change his mind. - a letter was written and sent to The Mount on September 1. - by the time Darwin returned home - the doctor had already changed his mind and was willing to help Charles out as best he could. The Voyage of the H.M.S. Beagle (1831-1836) - the Beagle sailed from Plymouth, England on December 27, 1831 when Darwin was 22. - when the Beagle finally left England, three months late, Darwin was already homesick, depressed and ready to question the wisdom of his decision to go. - he was deeply in love with a woman named Fanny Owen and he knew that leaving her would be the end of their relationship. - he then found out immediately upon departure that he suffered from terrible sea sickness that would persist the entire voyage. - an anticipated stop in Madeira did not happen because of poor weather. - the ship was then scheduled to stop at Tenerife, but this didn t happen either because the Beagle was quarantined due to an outbreak of cholera back in England. - instead the boat stopped off at St. Jago, a member of the Cape Verde islands off the west coast of central Africa. - Darwin was in ecstasy - the lush tropical vegetation was more than he had ever imagined. - the island was a geologists dream - and after two days geologising, Darwin had worked out what he thought was the geological history of the island. - the islands were volcanic in origin but by looking at the deposition of shells in the horizontal bedding of cliffs of the island he deduced that the island had experienced a gradual elevation over time. - this was a daring interpretation that was not in line with accepted dogma. - this interpretation was strongly influenced by his reading of the first volume of Charles Lyell s new book Principles of Geology.
- before leaving England, Darwin had heard only negative things of Lyell, particularly from Sedgewick during their trip to Wales. - Darwin was warned by Sedgewick not to take Lyell s views seriously. - what his Cambridge professors disliked so intensely of Lyell was his insistence that the earth s changes were not necessarily progressive in nature. - Lyell s earth was always changing, but not directed to any future point. - Lyell argued that there was no obvious connection between Christian doctrine and the geological history of the earth. - Lyell also argued that the fossil record was not reflective of an increasing perfection of organisms over time - he pointed out that very complex animals and plants had lived long ago. - the other major theme of Lyell s book was that the agencies at work today - volcanic activity, weathering, etc. - were acting in the past. - nothing could happen faster or slower than today - there was no need to invoke any special events. - Lyell s thinking thus diverged considerably from the Christian influences of the major geologists of his era. - this perspective is now called uniformitarianism. - Darwin applied this Lyellian viewpoint throughout the rest of the voyage. - Darwin was wonderfully preadapted to collecting and he had the full support of Fitzroy. - Captain Fitzroy was extremely accommodating to Darwin, dropping him off at various locations throughout South America for weeks at a time, heading back out to do the surveying work that was the reason for the trip and then returning to pick up Darwin at specified times and places. - scientific collections from remote areas where valuable commodities in Darwin s time, and Charles knew the great value of such a collection and the considerable prestige that went along with the person who collected the material. - an early disagreement occurred during the voyage between Darwin and the ship s naturalist and surgeon, Robert McCormick. - McCormick quickly saw that Fitzroy was going out of his way to ensure Darwin was able to collected wherever and whenever possible. - as a result McCormick resigned his post when the Beagle was in Rio de Janeiro in May of 1832 and arranged his return to England aboard the HMS Tyne. - Darwin was extremely fortunate in having the family wealth to accumulate his collection and the blessings of his father, who ended up signing all the checks and having his London bank honor all those dubious-looking calls on his account from South America. - Darwin did a careful job of collecting - having called upon experts from the British Museum prior to leaving for advice, etc. - he also concentrated on collecting small, overlooked organisms - many insects, small reptiles, fish, spiders, corals, barnacles, and other invertebrates. - he also made extensive collections of plants for Henslow. - as expected, he kept meticulous records. - the size of the Darwin s collection was impressive - all together 8 consignments were received by Henslow at Cambridge.
- the sheer volume of material forced Henslow to rent an unused lecture room at the University to store all the boxes. - he most influential place of call was the Galapagos Islands, a small cluster of 15 islands 600 miles off the coast of Ecuador. - coming from his extensive experiences on the mainland, Darwin was at once struck with the fact that the Galapagos were very recently formed and were volcanic in origin. - Lyell had prepared Darwin for his approach to these islands, writing about the problems of accounting for islands species. - Darwin made some very important collections here - most notably a series of finches (that are now called Darwin s finches) and a number of mockingbirds. - Darwin provisionally classified these finches into different subfamilies on the basis of their beak morphologies. - in uncharacteristic fashion, he failed to label the birds he collected to their island of origin. - that differences may exist among islands was brought to his attention by a British resident named Nicholas Lawson. - according to Lawson, tortoises from different islands could be identified depending on the degree of flaring of the shell. - Darwin failed to put any importance to this observation at the time. - after leaving the Galapagos, the Beagle stopped in at Tahiti, New Zealand, Australia and Tasmania, and South Africa, and back to South America before returning to England. - the Beagle returned to port five years later on October 2, 1836. - Darwin made immediately for home, and walked into The Mount on Wednesday October 5, 1836. - Darwin was already famous upon completion of the voyage due to the excellence of his many collections and some spectacular fossil finds in S. America. - Darwin s stature as a scientist was enhanced over the next 10 years by publishing books on the Beagle collection and from a personal narrative of his voyage. - as Darwin grew older, he began to shun the spotlight, retreating to a quiet rural life at Downe house in Kent, about 15 miles south of London. - there exists continuing confusion about whether Charles thinking changed suddenly during the voyage of the Beagle, particularly whether he underwent some sudden transformation into an evolutionist. - this just isn't true. - he began his voyage quite orthodox in his thinking about natural theology, species and religion and finished up that way as well. - there is no doubt that his visit to the Galapagos Islands in 1835 had a profound influence on his thinking. - this did not happen during the voyage but about a year afterward in April 1837 when some mockingbirds he had given to his friend the ornithologist John Gould were returned to Darwin and identified as distinct species, previously undescribed. - this relevation by Gould had a major impact on Darwin. - Darwin had initially thought that these were just varieties of the same species.
- if each island had its own species of birds, as Gould had shown, then perhaps species are not unchangeable after all! - perhaps the mockingbirds diversified into a range of forms on each island because of their geographic isolation! - perhaps there is no logical distinction between geographic variants and species. - shortly after this bombshell was dropped, Darwin went to a talk by Gould at the Zoological Society and hear him announce that the rhea Darwin had collected was in fact a new species as well - named Rhea darwinii. - this was the crucial turning point of Darwin s life - he thought immediately back to the stories of distinct tortoises, iguanas, and finches on different islands. - he went back and tried to study the finches he had collected but failed to label properly. - he even wrote to Fitzroy and asked to borrow his collection of finches. - he wasn t successful. - shortly after this, Darwin began his first notebook on what he called transmutation. - Darwin was not scared by the lack of evidence and the repulsion that the established scientific community in England had at the possibility of evolution. - from this point on the topic of transmutation, or the transformation of species, became his lifetime work. - notebooks quickly filled - A to F, an M and N notebook for what he called metaphysics and morals. - in his writings over the next two years, it is possible to trace the development of his theory - because of his detailed notes, we know that the crucial day this occurred was on September 28, 1838 when he happened to re-read Malthus' Essay on the Principle of Population. - Malthus' essay simply puts forth the argument that there must exist a severe struggle for existence each generation - only a small fraction organisms produced survive to maturity. - here's what Darwin wrote in his autobiography: "Fifteen months after I had begun my systematic inquiry, I happened to read for amusement Malthus on Population, and being well prepared to appreciate the struggle for existence which everywhere goes on, from long-continued observation on the habits of animals and plants, it at once struck me that under these circumstances favorable variations would tend to be preserved, and unfavorable ones to be destroyed. The result of this would be the formation of new species. Here, then, I had at last got a theory by which to work." - Darwin was struck by the similarity of what farmers and horticulturists do (artificial selection) and the process of natural selection. - as a result, Darwin corresponded with many breeders to gain insights into the genetic basis of heredity and the source of the variation that was being selected. - on two occasions Darwin actually circulated a detailed questionnaire among plant and animal breeders - Darwin had basically formulated his theory of evolution by natural selection by 1838.
- this was a full 21 years before the Origin was published in 1859. - on two occasions before the Origin was eventually published, Darwin had put his theory to paper in what he called his species essay. - in 1842 he had written a 35 page manuscript on the topic of transmutation. - in 1844 he had greatly expanded this manuscript into a carefully argued 230 page manuscript that took him 6 months to write. - this manuscript was completed 15 years before the appearance of the Origin. Why did Darwin stall? 1. Fear - Robert Chambers in 1844 published anonymously Vestiges of the Natural History of Creation in which he argued for the evolution - very similar to Lamarck's arguments about the gradual perfecting of evolutionary lineages. - it was a provocative and highly controversial book and was roundly condemned by all leading biologists in England. - Darwin was shocked by the similarity of some of the theories to his. - Chambers had argued that species were not immutable and garnered much of the evidence used by Darwin. - this included integrating evidence from geology, the fossil record, embryology, classification, comparative anatomy and behavior. - Vestiges was a national phenomenon - it went through 3 publications in its first year, was translated into German and by 1860 had sold 24,000 copies. - the venom by which the leading scientists of his day lambasted Vestiges certainly made Darwin concerned. - the most vitriolic attack was by his mentor Adam Sedgewick in 1845. - Darwin knew that all the criticisms leveled at Chambers by Sedgewick would be used against him, when he put forward his version forward. - therefore, Darwin took this opportunity of addressing all possible arguments against biological evolution prior to the publication of the Origin in 1859. - this he did with considerable success. 2. Credibility - one of the major criticisms leveled at the author of Vestiges was his amateurish knowledge of zoology, particularly comparative anatomy, embryology, classification, and the nature of species in particular. - how could a serious argument be leveled by a person who was clearly only superficially familiar with these areas? - Darwin realized that there was a serious credibility problem to be faced up to. - Sedgewick made these points and it is possible that Darwin would have been able to ignore them. - however, his close friend Joseph Hooker (who Darwin deeply admired) made very similar criticisms. - Hooker said that nature was often a muddle and species were very difficult to define on morphological grounds.
- Darwin realized that for him to convince the leaders of the scientific community, he had to become knowledgeable about the nature of species. - he therefore embarked on a project to investigate the systematics of barnacles. - Darwin s research into his beloved barnacles lasted for eight years and resulted in a fourvolume treatise that is still the authority on this group today. - the result was as anticipated - Darwin had national and international acclaim as a systematist of note whose arguments on species could be taken seriously. 3. Emma - Darwin s wife Emma was deeply religious. - this was an obvious source of angst for Charles who knew how upset Emma would be at seeing his ideas published. - after he completed his 1844 manuscript, he wrote a long letter to Emma outlining that in the event of his sudden death she should publish this manuscript posthumously and detailing the precise instructions of the best editors to send the manuscript to. - not surprisingly, at the top of the list was his valued friend Charles Lyell, followed by Forbes, Henslow and Hooker. - all of these men were highly esteemed scientists and good friends. - it was very clear from this letter that Darwin did not look forward to the controversy that he knew would result. - he also knew how Emma would be devastated. - Darwin began working on his big book that was to be four times larger than the Origin in 1856. - he was halfway through it when an essay arrived on his desk from Alfred Russel Wallace (who had arrived at the same conclusion as Darwin from basically the same background as a naturalist). - Lyell and Hooker convinced Darwin to publish an extract of his big book, together with Wallace s essay, in the Journal of the Linnaean Society in 1858. - as suggested, the papers were presented together at a meeting on the Linnaean society of London on July 1, 1858. - it was another year before Darwin's book, On the Origin of Species, was published - November 24, 1859.