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5 CHARLES DARWIN BIOGRAPHY 790L CHARLES DARWIN NATURALIST & AUTHOR Born February 12, 1809 Shrewsbury, England Died April 19, 1882 Downe, England By Cynthia Stokes Brown, adapted by Newsela Before the 1800s, scholars generally assumed that living organisms remained as they were created, never changing. Charles Darwin shattered this idea by presenting evidence that species do change over time. He called the process that species go through “natural selection.” 2 3 Setting out to sea Charles Robert Darwin was born the same day as Abraham Lincoln in 1809. Both of these men helped reshape the way we look at the human race. Darwin was the fifth of six children. His father was a doctor and businessman. His mother came from a wealthy family. She died when Darwin was 8, and his older sisters raised him. His family was Unitarian (a Christian sect) and abolitionist (anti-slavery). Both of these were uncommon in that time. Darwin considered himself a religious man. Darwin’s father pushed him toward medicine or religious studies, but Darwin had other ideas. His heart was set on becoming a naturalist. He went to university in Scotland, and finished at Cambridge University in England. When he was 22, Darwin joined a ship going on a voyage to South America. It was only supposed to sail for two years. However, the trip on the HMS Beagle ended up lasting almost five years and going around the world. It gave Darwin the opportunity to observe natural life in many different places. Darwin visited the Galápagos Islands, 14 unique islands about 600 miles off the coast of Ecuador in western South America. He found animals and birds slightly different from each other on each island. Darwin collected many samples to take back to England. Famously, he brought back different finches. A finch is a small bird. Darwin showed his finches to bird experts, called ornithologists, in England. They told him that he had about a dozen species of finches. No one had ever seen them anywhere else. Darwin examined the birds’ beaks. He noticed that each bird’s beak had adapted to the type of seeds available on its island. The need for food had caused the shape of each beak to develop over time. Darwin wrote reports about his trip. Soon he was elected to the famous Royal Society of London. It is a group of famous scientists. Shortly after, Darwin married a cousin of his, Emma Wedgwood. They had 10 children. Two died as infants and one died at age 10. Emma and Charles were very happy together. Near the end of his life, he told his children that she had been his greatest blessing. Darwin’s key idea Darwin was only 30, but he had already developed his key idea: small changes occur when creatures reproduce. Some creatures are helped by these changes. The creatures that benefit from the changes are more likely to reproduce and pass on those characteristics to their offspring. Over time, these changes can result in new species. This was just what he believed had happened on the Galápagos Islands. Painting of the HMS Beagle at Tierra Del Fuego, by Conrad Martens Darwin did not rush to publish his idea. He wanted to gather more evidence. He didn’t want to upset people who believed that God had created the world in a single moment. Darwin struggled with his findings. He tried to find a way to balance his religious beliefs with the scientific evidence he had uncovered. 4 5 It took him almost 20 years before he published his theories. In 1858, another English naturalist, Alfred Russel Wallace, sent Darwin a letter outlining his own theories. Wallace had come up with ideas similar to Darwin’s. Like Darwin, Wallace had developed his theories from years of research out in nature. Wallace’s letter clearly motivated Darwin to put his own ideas into print. His book, On the Origin of Species, appeared in 1859. By the end of the twentieth century, Darwin’s theory of evolution had plenty of evidence supporting it. His theory was now accepted as fact. Darwin’s ideas became the foundation of modern biology. Darwin did not know the Earth’s age. Educated people in England thought that maybe it was tens of thousands of years old. Darwin realized that it must be older. More time would have been needed for species to evolve. He estimated the Earth’s age at about 300,000 years. Much later, the Earth was proven to be 4.56 billion years old. That’s more than enough time for evolution to occur. The introduction stated Darwin’s main idea: More individuals of each species are born than can possibly survive. Consequently, there is a constant struggle for existence. Any being that has an advantage, even a small one, will have a better chance of surviving. Thus it is naturally selected. These individuals that survive will tend to pass down their traits to their offspring. Darwin presented three kinds of evidence in support of his theory of natural selection. First, fossils showed that species have changed over time. Second, species are descended from local ancestors. Third, he found unexpected similarities between species. For example, cats, whales, bats, and humans are very different animals. Yet, they all have fingers. The finger bones showed that these species are all related to each other. Darwin’s book caused a huge controversy. Still, within 10 years, many scientists accepted his ideas. New evidence since then has clearly supported Darwin’s theories. Biologists have been able to watch species change in relation to their environment. Scientists have discovered the structure of DNA. They now understood how it passes down traits through generations. Occasionally errors, called mutations, get passed down as well. Genetic and fossil evidence has proved that the human species emerged in Africa. Scientists now believe we evolved from chimpanzees. 6 Darwin also didn’t understand how changes occurred in reproduction. He knew changes happened and could be magnified. Dog breeders did this when they selected animals with the traits they wanted. They let animals with traits they liked reproduce together. They didn’t let them reproduce with ones that didn’t carry the traits. Over time this led to new breeds of dogs. It was called artificial selection, or breeding. Darwin called his idea “natural selection” to contrast it with this planned evolution. A quiet life of observation Darwin spent most of his life on his farm with his family, writing and studying. Darwin wrote thousands of letters to people all over the world. He was always asking questions and seeking information. Darwin continued observing the natural world and recording what he saw. During his life he studied bees, orchids, ants, rabbits, pigeons, earthworms, and insect-eating plants. Darwin’s other famous work was The Descent of Man, and Selection in Relation to Sex (1871). In this book, he argued that humans descended from apes. His critics drew him in cartoons with a monkey’s body. Darwin guessed that this evolution must have occurred in Africa, since that’s where the apes lived. But Darwin never had any solid evidence for this. 7 Darwin wrote well and his books sold well. His total earnings on sales came close to $500,000 in modern terms, an impressive sum for science books. His best-known sentence is this final one at the end of On the Origin of Species: There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved. Last days, lasting legacy All his life, Darwin suffered from stomach problems and heart palpitations. They were never explained. He died in 1882 at the age of 73. He was buried in Westminster Abby in London, not far from the tomb of Sir Isaac Newton. Time has confirmed that Darwin opened a new era in our understanding of the living world. He showed us how organisms of today are the product of a long process of change, the greatness of evolution itself. An 1871 cartoon lampooning Darwin 8 9 Timeline of Darwin’s life 1828-1831 Attends Cambridge University 1817 Darwin’s mother dies when he is 8 years old 1831-1836 Travels aboard the Beagle 1839 Elected to the Royal Society of London 1809 Born in Shrewsbury, Shropshire, England on February 12 1800 1839 Marries Emma Wedgwood 1825-1827 Attends University of Edinburgh 1810 1820 1809 Abraham Lincoln born in Hodgenville, Kentucky 1827 German composer Ludwig van Beethoven dies 1818 Mary Shelley publishes Frankenstein anonymously During the time of Darwin 1830 1840 1851 Death of 10-year-old daughter Anne 1850 1848 Karl Marx publishes The Communist Manifesto 1837 Inventor Samuel Morse patents his electric telegraph Sources Browne, Janet. Charles Darwin: The Power of Place. Princeton, NJ: Princeton University Press, 2002. 1871 Publishes The Descent of Man, and Selection in Relation to Sex Browne, Janet. Charles Darwin: Voyaging. Princeton, NJ: Princeton University Press, 1995. Heiligman, Deborah. Charles and Emma: The Darwins’ Leap of Faith. New York: Henry Holt, 2009. 1859 Publishes On the Origin of Species 1876 Writes his autobiography, which was published posthumously in 1887 Quammen, David. “Alfred Russel Wallace: The Man Who Wasn’t Darwin.” National Geographic, December 2008. http://ngm.nationalgeographic .com/2008/12/wallace/quammen-text. 1882 Dies in Kent, England, on April 19 1860 1870 1880 1879 Thomas Edison tests his first light bulb 1869 Dmitri Mendeleev devises the periodic table 1868 Astronomer Henrietta Swan Leavitt is born 1866 Gregor Mendel publishes Experiments on Plant Hybridization, becoming the “father of modern genetics” 1861 The American Civil War begins 13 Image credits An 1881 photograph of Charles Darwin © Bettmann/CORBIS A painting of the HMS Beagle at Tierra Del Fuego by Conrad Martens, public domain A caricature of Charles Darwin from 1871 © PoodlesRock/CORBIS Articles leveled by Newsela have been adjusted along several dimensions of text complexity including sentence structure, vocabulary and organization. The number followed by L indicates the Lexile measure of the article. For more information on Lexile measures and how they correspond to grade levels: http://www.lexile.com/about-lexile/lexile-overview/ To learn more about Newsela, visit www.newsela.com/about. The Lexile® Framework for Reading The Lexile® Framework for Reading evaluates reading ability and text complexity on the same developmental scale. Unlike other measurement systems, the Lexile Framework determines reading ability based on actual assessments, rather than generalized age or grade levels. Recognized as the standard for matching readers with texts, tens of millions of students worldwide receive a Lexile measure that helps them find targeted readings from the more than 100 million articles, books and websites that have been measured. Lexile measures connect learners of all ages with resources at the right level of challenge and monitors their progress toward state and national proficiency standards. 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