A list of famous scientists would be incomplete without Charles Darwin, who determined the theory of evolution through the mechanism he called “natural selection.” However, Darwin rarely used the word “scientist,” and he never used it even for himself. He was famous for his great advances in the field of geology, but he rarely called himself a geologist; he greatly shaped our understanding of plant physiology, but he said he was not a botanist. Darwin considered himself a naturalist in the broadest sense of the word. His success was based on the way he pushed the boundaries between different fields of study and asked questions about them.
Who Was Charles Darwin?
There were many factors behind Darwin’s scientific education: his father was a medical doctor; he was the grandson of the famous inventor and philosopher Erasmus Darwin by his father; and the grandson of the Wedgwood Pottery founder, a technologist named I. Josiah Wedgwood, by his mother. As they grew up in Shropshire, he and his brother were curious about chemistry, and they found enough money and space to set up a lab of their own. This was Darwin’s only laboratory; he began and continued his scientific career at home.
As the family’s younger son, Darwin needed a profession. There were only a few respectable options. The most obvious one was to be a doctor like his father, so he studied medicine for a while in Edinburgh. But he left the school without graduating and went to Cambridge to study for a general undergraduate degree in 1828 to work in the church—it was a common career for people in his social class. In Edinburgh, Charles had a keen interest in natural history; although he did not like the anatomy lessons and skipped the class, he wrote his first known scientific work after spending hours on the beach with zoologist Robert Grant. This was an article on the seaweed-like sea creature Flustra.
Darwin was a popular and harmonious student in Cambridge. He went to concerts and parties. But he was also a passionate insect collector and became friends with Adam Sedgwick, a professor of geology, and John Henslow, a professor of mineralogy and botany. Both of these people had a big impact on his scientific education.
Charles Darwin to build his reputation
Charles Darwin discovered her letter proposing that Henslow participate in a naval survey of South America when she returned home from her post-graduation field trip with Sedgwick. He would join the Imperial Ship Beagle as a companion to the free naturalist and captain Robert FitzRoy. It was proposed for his budding scientific talent as well as his social position and calm temperament. “He’s not yet a natural scientist,” said Henslow.
The ship Beagle sailed on December 27, 1831. The voyage was supposed to last two years but was extended to five. For Darwin, this was a life-changing experience. When he left, he was a 22-year-old rookie with no long-term plans. When he came back from his trip around the world, however, he was a respected member of the scientific community.
Charles Darwin’s theory about Earth’s crust
Throughout the voyage, Darwin gained practical scientific skills: observation, compilation, protection, rigorous record-keeping, classification, and microscope use. He put samples of plants, birds, insects, fossils, and all kinds of sea creatures inside the crates and barrels and sent them to England. These collections were important but not unique; there were other collections in South America too. Darwin once jokingly said, “There are more Naturalists in the country than Carpenters or Shoemakers or any other honest trade.” Darwin was different from others because he knew how the things he had collected fit together by making large-scale comparisons in the fields of geography and time.
He traveled hundreds of miles on horseback in the Andes Mountains and saw the evidence of almost unimaginable changes in the terrain. The fossilized trees that once sank into the water now stand in the highest passages of the mountains. When he decided to sail with a ship after an earthquake, FitzRoy showed him the evidence of a slow but steady relative altitude change of the land and sea. In his newly published theory, Charles Lyell agreed completely with Darwin’s observations, claiming that the current Earth was not the result of a single major disaster but rather the gradual operation of known causes over thousands of years. He combined his observations throughout the continent onto roughly glued paper to create long geological cross-sections. Giant blocks rising and falling on the molten core below the Earth’s crust were used to explain the new theory.
New hypotheses from Charles Darwin
Although Darwin said that he blindly combines all kinds of phenomena and then draws general conclusions from them, his method was much more complex and ingenious than that. He especially brought together a large amount of evidence to support his printed arguments, but he was never afraid to establish an ambitious hypothesis at an early stage and then look for counter-evidence to test this hypothesis. It was suggested from his notebooks that Darwin began to take note of many surprising ideas only after returning to England in October 1936, including his theory of the origin of species, which he published several decades later. When he returned to England, he became famous in scientific circles, thanks to Henslow, who distributed his booklet on geology. He was now celebrated by prominent scientists, and he had many research opportunities.
Using the uplift and subsidence hypotheses, Darwin came up with an answer to two of geology’s most controversial questions. One was a striking success, and the other was, in his own words, “a long-lasting huge pot.” Darwin was aware of the deadlock posed by ocean coral reefs. Because coral polyps could not live in waters deeper than sixty meters, proving their existence was difficult. Lyell recently argued that they must have grown in underwater volcano cones (mouths).
However, based on the large-scale subsidence theory, Darwin suggested that corals first formed in shallow waters around the islands and then followed the gradual collapse of the islands within generations. This elegant solution ensured Darwin’s place among the world’s leading scientists. When he returned to England, he was elected secretary of the Geological Association in March 1883, and he quickly started to evaluate the possibility of a university career.
Charles Darwin and a biographical sketch of an infant
Darwin had now turned his attention to a series of stunning terraces stretching around the Great Glen valley system, called “parallel roads,” in Glen Roy, on the mountainous terrain of Scotland. Geologists argued that the valleys, which were once thought to be man-made, previously contained lakes, and the lowering and rising waters carved these roads. But there was no trace of the huge dam sequence implied by this theory. Darwin suggested that the seawater, which was discharged as the landmass increased, must be the reason. But this was also problematic, as there was not a trace of sea creature fossils. Shortly after it was published, Louis Agassiz opposed Darwin’s theory with the argument that these large dams were made of ice from the Ice Age. This was a lesson for Darwin to be more prudent about what he made public.
Shortly after his field trip to Glen Roy, Darwin was elected a member of the Royal Society in January 1839. Five days later, she married her cousin Emma Wedgwood, and soon their first child was born in December of the same year. Darwin, who was always an observer, recorded all aspects of his son William’s life during his infancy. He used his notes for the first time in his book The Expression of the Emotions in Man and Animals and later in his article “A Biographical Sketch of an Infant,” published in Mind, a psychology publication founded in 1877.
The evolution of evolutionism
In 1842, Darwin and his family moved to the village of Downe, near the city. It was carefully calculated to be close enough to London to maintain professional and personal ties while being far enough away to deter unwanted guests. For the rest of his life, this place became his home and workplace. His wife and children provided the loving and stable life he needed. Now, Darwin was a prominent writer who proved himself with his best-selling book about his Beagle voyage. He also had a chronic illness. Nevertheless, he made a very important friend, both personally and professionally.
The young botanist and explorer Josef Hooker, who would be the manager of the Royal Botanical Garden in Kew, was appointed to identify Darwin’s Beagle plant specimens. They started a correspondence, and for the next forty years, Hooker became the touchstone of Darwin’s ideas.
Darwin was now settled, and all the amateur and professional scientists around the world who wanted to share their findings with Darwin about plants, animals, and people were only allowed to talk with Hooker. This included explorers, diplomats, and those who settled in a colonial land. Hooker would be one of the few people with whom Darwin shared his theory about the diversity of organic life and how all living things came from a single common ancestor. Darwin had been developing this theory since the 1830s.
Darwin’s new profession: Ecologist
During his voyage on the Beagle, Darwin became increasingly aware of the difficulty of distinguishing between different species and variants, the surprising similarity of many extinct fossils and existing creatures, and the precise harmony of many organisms with their environment. The idea that species may transform over time was a matter of disagreement but not new; French biologist Jean-Baptiste Lamarck suggested that the beneficial properties acquired by one generation could be passed on to the next. Authors like William Paley explained that this harmony was a result of the divine design in nature.
During his journey around the world, Darwin encountered an enormous diversity of species, including some explicit relatives. On his return to England, he explored dog and pigeon breeders, observing the dramatic change in the characteristics of pets that could be produced in just a few generations, guided by the naturally occurring diversity. Thomas Malthus’s Essay on the Principle of Population Study, which explains how population growth is limited to the point of competition for resources, gave Darwin the piece he needed to draft his new theory.
He argued that any trait that would help an individual survive enough to give birth, be it animal, plant, bird, or human, would be transferred to subsequent generations disproportionately. This principle of “natural selection” was true for all physical traits, whether it was coloration for camouflage, the ability to fight or escape, or the ability to access food sources that others could not reach.
With this mechanism, Darwin realized that all the populations, like finches, that he collected from different islands in the Galapagos, even though John Gould’s subsequent work clarified this, could adapt to local conditions. Given enough time, the offspring of such organisms could diversify, occupy different environmental niches, and evolve into new species. Although the word “ecology” was not available in English until 1876, Charles Darwin was already an ecologist in many respects.
The birds coming from Malaysia
The way things went with geology also happened with biology: Darwin’s whole research program was shaped by the bird species once he outlined the global theory. Even the eight-year taxonomy study he conducted on living and fossil rock mussels, which was finally published in 1851, was a conformity study if it is considered in the light of his main theory. While working on mussels, Darwin was working on a new book called Natural Selection, which would never be published, and he was collecting data from all areas of natural history, mostly through the growing network of correspondence.
One of them was a naturalist and commercial collector, Alfred Russel Wallace, who sent bird samples from Malaysia to Darwin in late 1856. They both knew they shared similar ideas. Darwin told Wallace that he plans to publish a book on the species problem. Except for some chapters of this big book, they had drafts explaining almost all the theory, one of which was previously written in 1842 and one in 1844. In 1858, Wallace sent Darwin a text with a similar idea to his theory about how species change over time. This helped Darwin’s theory get published faster.
Fearing that he would lose his priority in the publication but also distracted by two of his children having serious illnesses, Darwin sent Wallace’s text to Charles Lyell as requested. Lyell and Hooker arranged for both Wallace’s text and Darwin’s loosely written text to be read at the meeting of the Linnean Society. Darwin was destroyed by his baby son’s death, so he was not there. Almost nobody noticed his article, but Darwin did not give up. He quickly expanded the original text with materials from his main book and completed his book “On the Origin of Species by Means of Natural Selection” in less than a year. Contrary to Wallace, Darwin had a social position, a scientific reputation, and a depth of knowledge that would allow him to be taken seriously in his new book. This book was the biggest breakthrough in the life of Charles Darwin.
His creative experiments
Darwin did not end his career with the publication of The Origin of Species. Although he suffered from chronic disease attacks, he was only fifty years old, and most of his books had not yet been published. He still had no theory of how heredity worked. Gregor Mendel developed this theory, now called genetics, in the 1860s. But his work was not understood until after Darwin’s death, nor did Darwin ever hear of Mendel’s work.
Ten years after the Origin of Species, he published his extensive two-volume work The Variation of Animals and Plants under Domestication, which resulted in Darwin’s description of the hypothetical mechanism of inheritance he called “pangenesis.” He argued that particles circulating in body fluids that could be passed from parents to children, namely sediments, act as catalysts for the development of certain organs. But not many people were convinced, and his cousin Francis Galton’s experiments with blood transfusions didn’t show anything to back up his claims.
The next two books, The Descent of Man and Selection in Relation to Sex and The Expression of the Emotions in Man and Animals, were written to show that some human-appearing dimensions such as aesthetic sensibility, conscience, and even religious feelings might be part of the evolutionary continuity in the rest of the animal kingdom. The process of natural selection was helped along by the process of sexual selection. Organisms not only had to live long enough to reproduce, but they also had to have traits that would appeal to their offspring.
However, Darwin’s main struggle was not with people or even animals, but with plants. He saw humans only as a distinct variety of primates, but there were no strict boundaries between animals and plants. In Down, he conducted innovative experiments in his garden and conservatory, including hybrid crossing to ensure greater diversity. He studied plants that show animal-like behaviors, such as vines or insect-eating plants, and that are sensitive to external stimuli.
Charles Darwin’s last book
Though he was criticized later in his life for the amateur-looking nature of his working methods, Darwin was a skilled experimenter and by no means away from the advances of science. He was also in contact with the university laboratories established in Germany, thanks to his botanist son Francis, who conducted experiments for him. He examined the importance of regulating the habitat for the cultivation of seeds that are brought from one end of the world to another. He was one of the first people to use scientific surveys and sign petitions to Parliament about how science affects public life.
Darwin’s latest book, The Formation of Vegetable Mold through the Action of Worms, published in 1881, was a return to the line of investigation that began decades ago and was the result of experiments he made with his children at home. It was also a pioneering work in showing the importance of seemingly insignificant creatures as well as the full cycle of nature in a wider environment. Darwin saw his last book sell more than all of his previous books, and the next year Charles Darwin’s life ended. Because of his groundbreaking ideas in science and his fame, he was buried in a beautiful ceremony at Westminster Abbey in London.
References:
- FitzRoy, Robert (1839). Voyages of the Adventure and Beagle, Volume II. London: Henry Colburn
- Freeman, R. B. (1977). The Works of Charles Darwin: An Annotated Bibliographical Handlist. Folkestone: Wm Dawson & Sons Ltd. ISBN 978-0-208-01658-4. Retrieved 4 November 2008.
- Freeman, R. B. (2007). Charles Darwin: A companion (2nd online ed.). The Complete Works of Charles Darwin Online.
- Herbert, Sandra (1980). “The red notebook of Charles Darwin”. Bulletin of the British Museum (Natural History), Historical Series (7 (24 April)): 1–164. doi:10.5962/p.272299.
- Herbert, Sandra (1991). “Charles Darwin as a prospective geological author”. British Journal for the History of Science. 24 (2): 159–192.