rtluirirrr-;;--- -r--F- ---Itll Charles Darwin and Natural Selection r

I January 15, 2014 from the Print Edition

When you think of "Evolution", you will undoubtedly think about Charles Danuin, since he is the I

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many years of study and research during his travels or at home in his study in England. I

Charles Danruin was born in 1809 to a wealthy family in England. His father was a doctor and so he I

naturally wanted Charles to follow in his footsteps. Charles tried to meet his father's expectations, Iby enrolling in Medical School when he was 16, but found his interest was more in studying natural Ihistory. He loved to study insects (entomology), marine animals, etc. He was able to visit scientists 'and natural history enthusiasts throughout Europe where he joined societies and shared his I

excitement with other well-to*do scientists. I

When he was invited to join the HMS Beagle on it's journey around the world, in 1831, he accepted I

the invitation by Captain Fitzroy. The purpose of the voyage was to map and explore unknown I

lands. His father thought it was a waste of time, but his uncle encouraged him to go. The trip was Ia five-year expedition that took him around the world. His job was as a naturalist where he wassupposed to collect specimens and make observations about ptants and animals they came across. I

He was also a companion for the captain. He was to receive no pay for the position and in fact, had I

to come up with his own money to fund his place on the ship. He was only 22 when he started the Ivoyage.

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The ship sailed south and they first stopped at the Cape Verde lslands off the coast of Africa. There, IDarwin studied Charles Lyell's book about Geology and used it to understand the coral uplift in the Iislands. He eame up with the rdea that the earth is dynamic and is always changing, causing uplift,

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Nexto the ship sailed around the tip of South America, stopBing along the way to visit Argentina, IChile and other spots of interest. Darwin collected specimens, but also became interested in fossils ,he found in Argentina. For example, he studied the fossil of a giant sloth called Megatherium, and I

fossils of Glyptodon, a giant arrnadi!!o. He also studied a fossil of Toxodon u,rhich resernbles a Ihippopotomas. Danrin wondered why some animals became extinct, while others were replaced by

;similar but modified living decedents (like the armadillo and sloth).

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I fu"g"therium Glyptodon ToxodonI

I From South America, they then sailed to the Galapagos lslands, where Darwin started to put

. together his idea of natural selection. The Galapagos consist of 14 islands, with L3 different typesI of finches spread throughout. He figured out that winds carried a few ancestral finches from theI mainland of South America to the different islands, where, over a long period of time, their beaks

; adapted to the particular food on that island available to them. Look at a few of the finches and the

r way their beaks adapt to their food sources on the next page. We say that the finches exhibitEr----rr-----r-

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Glyptodon

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Toxodon

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adaptiv6 radiation because they radiate out from the ancestor in the middle like the spokes of awheel.

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After the Galapagos, the ship sailed around to Australia where he studied the biodiversity there andthe around the cape of Africa, and eventually back home in 1836. Darwin arrived home with manyspecimens, notebooks and an excitement to get started writing about all of his observations.

After the voyage, Darwin spent his time studying, writing and communciating with other scientists.His family money afforded him the prlviiege to be able to study and not have to work. Many

scientists in that day were from the upper classes in Europe. ln the years after the voyage, Darwinpublished 4 books, and wrote many scientific articles and papers. His most famous book is "On theOrigin oi the Species by Means of Natural Selection" where he lays out his theory of naturalselection. ln that book, he describes how species are developed through natural selection.Basically, nature selects the organism that can survive the best, having the best adaptations for hisparticular environment. A bird that has a beak that can eat the food available will survive over a

bird who's beak makes it hard to eat that particular food. There must be variation (for nature tochoose between), many offspring, and competition for resources in order for evolution to occur.

Darwin died in 1882 at the age of 73. His life was filled with the love for knowledge and the quest

for answers. His contribution to the understanding of the evolutionary process is remarkable.

Questions: (answer on another sheet of paper)

1. After reading this article, what would be a good ciet-inition of evolution?

2. What was Darwin's place in society and how did this help him to .o*. up with the ideas aboutnatural selection and evolution?

3. Why do you think some people call Darwin a scientist:s scientist?

4. Using evidence from the article, describe how natural selection occurs.

I 5. Using information from the article, list what is needed for natural selection to occur., from the print edition: Sabetl.r----r-------