Darwin and the theory of evolution

Author: Carlos A. Marmelada. carlosalbertomarmelada@yahoo.es
Date of publication: February 2009

No scientific theory has caused as much ink to flow as the theory of evolution. Ever since Charles Robert Darwin published his famous book graduate The Origin of Species in 1859, the controversy surrounding the scope and limits of this theory has been the subject of heated debate discussion. Within science, practically no one doubts the reality of the evolutionary fact, what is discussed is how evolution is produced, what are its causes, how it has developed, whether it has been slow and gradual or through sudden leaps that have occurred at specific moments. But the most bitter discussions have taken place beyond science. There is no doubt that one of the most intense debates between science and religion today is the one about the compatibility between the scientific theory of evolution and the religious doctrine of creation. 150 years after the publication of Darwin's work, the debates are still as open as they were then, perhaps even more vigorous and with renewed vitality. Behind the work is the author. But ... who was Charles Darwin really? Who was Charles Darwin really? His scientific theory was soon used as a weapon against religion. What was his intention: was he only aiming to establish an alternative scientific theory to the prevailing fixism, or did he also think he was providing scientific evidence in favour of atheism?

In 1809 Jean Baptiste Pierre Antoine de Monet (1744-1829), better known as the Chevalier de Lamarck, published the book in which he set out his evolutionary theories: La philosophie zoologique. On 12 February of the same year, Charles Robert Darwin was born into a well-to-do family in Shrewsbury, the county town of Shropshire, in the west of England, near Wales. He was the fifth of six children, four girls and two boys. His father, Robert Waring Darwin (1766-1848), was a physician of great repute, as was his paternal grandfather Erasmus Darwin (1731-1802), who had written a poem advocating an evolutionary view of life. His mother, Susannah Wedgwood (1765-1817), was the daughter of Josiah Wedgwood I, a famous potter from Maer who had triumphed with the start of the industrial revolution.

At his mother's express wish, he entered Reverend Case's Unitarian school for his early schooling. But the untimely death of Susannah Wedgwood in 1817 led Mr Darwin to make the decision to transfer his son to Dr Butler's boarding school. Darwin was never a brilliant student . In elementary school his grades were average and he was not a standout performer at university either. The reality is that he was an ordinary student.

Mr Darwin's dream was that his two sons would become doctors, so he sent them to study medicine at the prestigious University of Edinburgh. Charles moved there at the end of 1825, his brother having gone earlier. Young Darwin soon realised that he was not cut out for it. He found the lectures extremely boring; but the worst was when he had to go to attend for an operation; don't forget that in those days they were performed without anaesthesia. He only attended two of them, but the second one marked him for good, it was the operation on a child; that experience was so traumatic for him that he discarded final this profession, although he continued in Edinburgh for the rest of the course. However, it was not all wasted time; there he met the naturalist Robert Edmond Grant (1793-1874), an evolutionist and follower of Lamarck, who rekindled his passion for nature by introducing him to various scientific societies in Edinburgh. It was around this time that Darwin gave his first scientific lecture in the cellars of the Plinean Society.

Grant presented Darwin with Lamarck's evolutionary doctrines and reminded him that his grandfather Erasmus had also been an evolutionist. But Darwin was not convinced by either of their arguments. At the time, Charles Darwin was a fixist, i.e. he believed that God had created all the species as they were then known and had distributed them around the Earth in the most convenient way for them. However, this was a situation that could not be maintained for long. His sisters helped him by explaining to his father the young Darwin's lack of vocation, mainly because of his poor time in the operating theatre. Although unhappy, Mr Robert Waring had no choice but to accept the situation. Worried about his son's future, fearing that he would dissipate into dissolute living, he decided that he should study theology at Cambridge in order to become an Anglican country parson. After some thought Darwin agreed; two reasons prompted him to do so. On the one hand, he did not dislike attending to the spiritual needs of the people, and on the other hand, this profession would leave him more than enough time to pursue his great hobby: being a naturalist.

Darwin spent three years at Cambridge. In January 1828 he entered Christ's College. He was not noted for the brilliance of his marks there either. He preferred to hunt, ride horses, or have fun with the group group of friends who formed the "Glutton Club" (the Glotton Club), rather than study theology. In early 1831 he passed the graduation examination with one of the highest marks among the group students who sat for the test , for which he did not aspire to grade. With hindsight it is paradoxical that Charles Darwin, the man whose scientific theories would be used by some as the basis for naturalistic atheism, had as his only academic qualification licentiate degree in theology; or, to be more precise, high school program in the arts.

His time at Cambridge was decisive in Darwin's life. In this illustrious university city he made friendships that would have a profound effect on him, including that of John Stevens Henslow (1796-1861), an Anglican minister and professor of botany. This eminent scientific priest took him into his inner circle. On Fridays he would hold a gathering of students at his house, inviting them to dinner and afterwards they would hold scientific gatherings. Henslow saw early on the great qualities of Darwin as a naturalist that were to characterise the public personality of the eminent British scientist in the future. These qualities had not yet surfaced, and remained hidden even from Darwin himself.

During the summer of 1838 he was on a geological excursion through Wales with Grant. When he returned home at the end of August 1831 he came across a letter that would, in the short term, change his life, and in the long term, change science's and society's view of man.

The British Royal Navy had decided to send one of its ships, the H. M. S. Beagle, to the waters of South America and Tierra del Fuego, to map the coasts, study the draught of the waters, measure the longitude of the Earth and collect all class information that would make it possible to produce better sea charts than those already in existence. The expedition would be under the command of Captain Robert Fitz Roy, and it was in fact the sea charts he produced that were used in the First World War to help the British fleet search for the German Wayside Cross Dresden, hidden in an inlet of Tierra del Fuego. The Dresden's second-in-command was Lieutenant Wilhelm Canaris, the future admiral and head of the Third Reich's counter-espionage services, who was eventually executed for conspiring against Hitler.

In November 1914, the naval division commanded by Admiral Graf von Spee had defeated a British naval fleet off the coast of Coronel, Chile. During his attempt to reach Germany from the Pacific, Spee needed a supply of coal, so he decided to seize some in the Falklands. Arriving at Port Stanley, he realised that Churchill had reinforced the British fleet with two battleships that had just entered service and were far more powerful than he could oppose. Although Spee tried to flee, he was hunted down, sinking all his ships except the Wayside Cross Dresden, which was able to escape because it was a little faster than its rivals, but lacking coal it was unthinkable that it could reach Germany, so its captain decided to take refuge in Tierra del Fuego, hiding for months in the nooks and crannies of its inlets, and ended up being sunk in 1915 off the coast of Chile. There is a curious anecdote about this issue: during the months of searching in Tierra del Fuego, some locals reported the exact position of the German ship in order to collect the reward; however, the British Admiralty rejected this information because in their naval charts, drawn up from the data collected by Fitz Roy, the Wayside Cross was supposed to be on top of a mound.

How did Darwin end up on H.M.S. Beagle? Fitz Roy had asked the Admiralty order to grant him the possibility of choosing a companion, a person who would be polite and pleasant to deal with, but also a scientist who was dedicated to gathering information of a naturalistic nature. Fitz Roy was a fervent believer and wanted to find empirical evidence of the global flood. His idea was to publish, on his return, the story of the voyage along with the scientific study of the samples collected. Darwin was not to be the official naturalist of the expedition, that honour fell to the doctor, but jealousy eventually got the better of him and he decided to leave the ship in mid-1832, leaving Darwin as the sole naturalist. Why did Fitz Roy ask to be allowed to take a companion on board? The rules of the British Navy prevented the commanding officer from making friends with the officers under his command; moreover, their dealings were to be limited exclusively to dealing with matters of the ship's government and everything related to their mission; there could be no other subject dealings, not even an informal conversation on unimportant subjects, let alone an intimate conversation about confidences. The rules were very strict on this point. Moreover, the voyages lasted for years, so the situation of the ship's captain was not enviable. In the circumstances, Fitz Roy's request was very reasonable.

Henslow heard of this and wrote to Darwin encouraging him to take advantage of this unique opportunity, and it was he who wrote the letter he received at the end of August. Darwin's father initially objected, considering the trip unworthy of someone who was to become a clergyman, but his uncle Josiah Wedgwood II helped him by persuading his brother-in-law to let him go. In early September Darwin met Fitz Roy in the English capital. Darwin made a very good impression on him, so Fitz Roy chose him as his companion. On 27 December 1831, the Beagle left Plymouth Harbour for Brazil. A stopover in Santa Cruz de Tenerife was planned, something that Darwin was very excited about, as it had been one of his dreams since he had read Humboldt. But it was not to be, as shortly before departure there was an outbreak of plague in London, and the Spanish authorities demanded a twelve-day quarantine for all those on board the Beagle before they could set foot on land. Fitz Roy refused and ordered to sail the next day. This is how Darwin's Spanish adventure ended.

He did, however, land in Cape Verde, where he spent a few days collecting samples. In San Salvador de Bahia and Rio de Janeiro he was able to appreciate the exuberance of the tropical flora and fauna, something he would remember with great pleasure all his life, not least because from his home in Rio he could enjoy the majesty of Corcovado. In Montevideo he experienced an attempted revolution and had to take up arms to defend a fort near the port, although he did not need to use them. In Argentina he met General Rosas, who was then engaged in a military campaign against the Indians of the Pampas. A few years after meeting Darwin, Rosas would become President of the country. This friendship got him out of trouble when a civil war broke out that caught him in the crossfire at the gates of Buenos Aires and prevented him from returning to the Beagle. A safe conduct issued in the name of Rosas allowed him to enter the city and join his ship.

It was in Argentina that he discovered fossilised skeletons of giant prehistoric animals in the same area where similar but smaller ones existed and which would later be adduced as evidence in favour of his theory of evolution. These findings in Bahia Blanca were, in the short term, more important to his elaboration of the theory of evolution than the subsequent collection of finches and tortoises in the Galapagos.

Darwin's voyage around the world lasted almost five years. In Tierra del Fuego he experienced a small tsunami, and his heroic behaviour in risking his life to save the boat that would allow them to leave and return to the Beagle earned him the admiration of the captain who, in gratitude, named a mountain near that beach after him. In Chile he witnessed a spectacular earthquake which, together with the expedition to the Andes, helped him to understand the geological transformations undergone by the relief, something that would harmonise with his theory of evolution. On the way back he would pass through the Galapagos archipelago, initially not noticing the variety of species of finches and tortoises, each located on different islands, so he did not pack them in separate boxes. However, the differences between the mockingbirds did catch his attention.

After the Galapagos, they passed through numerous islands in the Pacific. From his study he was able to develop an accurate theory of the formation of coral atolls. Some of the stops they made included Tahiti, Australia, New Zealand, South Africa, Brazil again and the Azores again. The Beagle's destination was London, but Darwin was dying to see his family as soon as possible, so as soon as they reached the British coast, Darwin set foot on land, which he did on 2 October 1836 (having sailed around the world for more than 40,000 miles in a voyage that had lasted four years, nine months and six days). When Darwin set sail from Plymouth as a young man of 22 who aspired to be a respectable scientist, he was now returning a man of 27 who had already earned the fame and admiration of the British scientific community as a reputable geologist before he set foot on land. It was then that Darwin discovered that Henslow had been reading Henslow's letters to him publicly in various scientific societies, so that the scientific community was already aware of his discoveries on subject geology and also of the great work he had done in recomputing thousands of samples of animals and plants from all over the world subject.

During the voyage on the Beagle Darwin was a fixist as well as a devout believer. So ... what was it that led him to believe that species transformed themselves and gave rise to new ones? As we said earlier, during his stay in the Galapagos he collected tortoises and finches without noting the island of origin, thinking that they formed homogeneous groups; once they arrived in London, specialists such as the ornithologist John Gold and the palaeontologist and anatomist Richard Owen studied the samples and, at the beginning of 1837, assured him that each group contained different species.

It was in March of the same year that he began to write down his ideas on the transmutation of species. He began with notebook B, followed by others (C, D, E, etc...), with A dealing with geology. In September of the following year, the book by the political economist Thomas Malthus fell into his hands: essay on the Principle of Population, first published in 1798. In this book, essay , Malthus expressed his conviction that humanity was heading for a great crisis due to the increase in population; if it continued to grow at the current rate, Malthus foresaw that in the future there would not be enough food for everyone and then the skill struggle for survival would begin. In Malthus' opinion, the main culprits were the poorer classes, as they reproduced in an uncontrolled manner.

However, the book also talked about plant and animal populations, stating that all species have a tendency to procreate beyond the available resources, so that only some of the offspring can survive. Darwin welcomed these ideas with enthusiasm, as they fitted perfectly with the vision of nature that was emerging in his mind. Malthus's book, together with his observation of the work that farmers and herdsmen did in artificially selecting the characters they wanted to pass on to their offspring, had given him the core topic to explain the engine of evolution, which according to Darwin, was none other than the natural selection of those randomly produced variations that favoured survival through better adaptation to the environment.

His reading of Charles Lyell, the most famous geologist of the time, and his own experiences during the voyage on the Beagle, had made him realise that the same thing could happen in the world of living beings as in geology: there could be gradual changes that would develop over long periods of time. The Galapagos specimens were a sample of the transformation of species by adaptation to the environment, and reading Malthus had provided him with the core topic to explain this transformation: natural selection would be the mechanism proposed by Darwin as the explanatory cause of evolution. Darwin already had the fundamental elements that would characterise his thinking. So why didn't he publish his ideas at the time? Why did he not publish his ideas at the time?

In 1839, twenty years before the appearance of On the Origin of Species, Darwin was already very clear about the instructions of his theory of evolution; however, he did not want to rush the publication of his ideas. He was well aware of the hostility with which they would be received and how much he stood to lose. There was no doubt in his mind, one slip up and his brilliant and promising career as a scientist would be over. It was not easy for Darwin to keep his change of interpretation of nature and man's place in it a secret. His doubts about religion were growing at subject . How did the biblical account of creation according to Genesis fit in with the new theory he was developing? His wife Emma Wedgwood (his first cousin, whom he married in Maer on 29 January 1839, after having drawn up a list of pros and cons of marriage) was a deeply religious woman, and Darwin did not want to hurt her feelings, although Emma was aware at all times of the intellectual journey her husband was embarking on.

Most of Darwin's historians and biographers agree that his conviction that his ideas would be rejected by the Anglican Church and the like-minded intellectual and political establishment not only held him back from publishing his ideas at the time, but also gave rise to a preoccupation that would eventually lead to the illness that would accompany him until his death.

By June 1842 he had become convinced that his theory was sufficiently elaborated to write a brief outline for private use. By the spring of 1844 the text had grown into a essay, in which, quite deliberately, Darwin avoided any reference to the origin of man and the action of the Creator. The book could have been published, but he declined to do so. He entrusted it to his wife Emma with a letter in which he asked her, in the event of his death, to do her utmost to publish it, convinced that its contents would be of great benefit to science. Why did Darwin not publish his essay in 1844? He was fully convinced of the social rejection of his evolutionary ideas. test was that in the same year an anonymous book was published (it was later revealed that the author was Robert Chambers, a Scottish journalist interested in scientific matters) graduate: Vestiges of the Natural History of Creation, which made an apology for evolutionism. Its scientific content was weak and some of the mechanisms proposed to explain evolutionary change were laughable. Darwin was deeply disappointed by Vestiges' geology and zoology, but what surprised him most was the virulence with which this work was attacked. The ideas expressed in Vestiges were broadly similar to those held by Darwin, but those of Vestiges lacked a solid empirical basis. Darwin spent the next five years, among other things, growing orchids and breeding pigeons to find further evidence in favour of his theory of the transformation of species through natural selection of random variations arising in modified offspring.

In September 1855, the young naturalist Alfred Russel Wallace published an article in which he spoke of the transformation of species. Darwin was not perturbed. Despite the insistence of his friends Lyell (a geologist) and Hooker (a botanist), Darwin remained reluctant to publish a book setting out his ideas. The situation changed radically on 18 June 1858. On that day Darwin received a brief manuscript from Wallace (who was then working in Indonesia) accompanied by a letter. The manuscript contained the exposition of the theory of evolution by natural selection. He had been beaten to it. The matter was settled by the joint publication of a paper on topic. Darwin then hurriedly set about writing a book in which he set out his ideas and provided a wealth of data in his favour. The Origin of Species was born.

The work was well received, but it aroused considerable controversy. Although it did not speak of the origin of man, it escaped no one's notice that man was not an exception in nature and that, according to Darwin's theory proposal , human beings should also be the fruit of natural selection and not the result of a divine creation. Famous in this regard was the confrontation between Bishop Wilberforce and Thomas Henry Huxley (popularly known as Darwin's bulldog) in 1860. In 1871 Darwin published The Origin of Man. In this book, he stops prissy and applies his idea that natural selection is the cause of the appearance of man, just as it has been the cause of the appearance of all other living things. He also states that humans have no special place in nature and that the spiritual Schools came from subject by gradual evolution. Paradoxically, this book did not cause as much of a stir as the 1859 book. The notion of evolution in the living kingdom had been gaining ground. Although Darwin believed that everything in us has an evolutionary biological origin, other evolutionists, and very good friends of his, such as Henslow, Asa Gray or Wallace, believed that human intelligence was the result of a creative act of God.

From Darwin's death on 19 April 1882 until the beginning of the 20th century, Darwinism slowly died out. Failure to explain the mechanisms of heredity seemed to doom the theory to its own intellectual extinction. However, the rediscovery of Mendel's work by three independent researchers: Hugo de Vries, Carl Correns and Erich von Tschermak allowed the creation of modern genetics, which in the medium term made possible the resurrection of Darwinism (although at first it seemed to support fixism). Hugo de Vries proposed a new theory of evolution, known as mutationism, which essentially eliminates natural selection as the main process in evolution. The mutationism proposed by de Vries was rejected by many contemporary naturalists and also by the so-called biometricians. According to them, natural selection is the main cause of evolution, through the cumulative effects of small, continuous variations. During the first two decades of the 20th century, mutationists and biometricists engaged in a bitter controversy, centred on the question of whether species appear suddenly through major (qualitative) mutations, or gradually through the accumulation of small (quantitative) variations.

It was not until the 1930s that a theory of evolution was developed that integrated Darwin's essential contribution, natural selection as the engine of evolution, with the newly discovered Mendelian inheritance. The main scientists who developed the synthetic theory of evolution were: Theodosius Dobzhansky, George G. Simpson and Ernst Mayr. In the synthetic theory, also known as neo-Darwinism, the interplay of mutation, genetic recombination of DNA, genetic drift, migration and natural selection were the factors that led to evolutionary changes in living things.

But the synthetic theory would have to face certain objections; on the one hand, in the 1960s, some mathematicians objected that there had not been enough time for evolution to have occurred following the mechanisms described by Darwin, and, on the other hand, the fossil record showed discontinuities that could not be explained by gradualism, so in the 1970s John Eldredge and Stephen Jay Gould proposed the theory of punctuated equilibrium. According to these authors, evolution would be characterised by long periods of stable time, stasis, alternating with brief lapses (a few millennia) in which changes would occur abruptly. According to them, this would be more in line with the fossil record. Today the discussion between Darwinian gradualism and Gould's and Eldredge's saltationism is still under discussion.

150 years after his proposal Darwin's theory has become the mainstay of the life sciences. Today, as Theodosius Dobzhansky said, nothing in biology makes sense unless it is in the light of evolution. This could be extended to the biomedical sciences. Today, evolution as a fact is accepted by the vast majority of scientists. What is questioned is whether Darwinian natural selection has as much influence on evolutionary fact as the English naturalist supposed, some do not agree agreement that natural selection has such a decisive role in the evolutionary process. For this reason, some are calling for a new theory of evolution, a new synthesis, which goes beyond that of the neo-Darwinists proposal . Others argue that biochemistry presents insurmountable challenges to Darwinism and argue for the existence of an intelligent design in nature that can be described by the methods of science, a proposal that is raising heated debate. The idea that life has unfolded over time through an evolutionary process is a conquest of science that can no longer be reversed, as is the case with the big bang in cosmology and heliocentrism in astronomy. It is to Darwin's credit that he was the main architect of this idea that it took hold with such vigour. Nevertheless, the theory of evolution continues to face major challenges. The origin of the kingdoms remains hypothetical, and whether they developed from particular forms of primitive life remains a more or less coherent assumption. The same is true at the next level, that of the phylum. The origins of these basic organisational schemes of life are obscure, and are not guaranteed by the fossil record as understood by gradualism.