Charles Darwin - the bi-cententary

The 12th February 2009 was the 200th anniversary of the birth of Charles Darwin. Our member Dan Clery has written his story:

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Charles Darwin, born on the 12th February 200 years ago, came up with what is probably the most important idea in the history of science. He reasoned that plants, animals and all living things are not static and unchanging, remaining as they were made by a divine creator; instead they change subtly from one generation to the next and those that are better suited to whatever environment they find themselves in prosper and reproduce more, while those that are less well suited don’t. In this way, plants and animals gradually change, eventually developing into new species and producing the huge variety of nature that we see today. Darwin’s theory, evolution by natural selection, is at the root of our understanding about life on Earth: it explains why there is such diversity in nature, why we are here, and why we are as we are.

When Darwin graduated from Cambridge University in 1831, there was little sign of the revolutionary that he would eventually become. He was an enthusiastic and good natured young man from a well-to-do family, destined to become a country clergyman. He had, however, developed a passion for natural history, both as a boy and in his student years when he would scour the countryside around Cambridge looking for beetles.

Out of the blue, soon after graduation, one of his professors recommended him for the position of unpaid naturalist on a Royal Navy survey ship. He travelled to London and met Robert Fitzroy, captain of HMS Beagle, who was preparing to survey the coast of South America. Fitzroy was a deeply religious man who hoped that any scientific discoveries made on the expedition would provide evidence for the literal truth of the bible. Darwin was soon signed up and on 27th December 1831 the Beagle set sail from Plymouth.

Darwin suffered terribly from seasickness but when they arrived in Brazil he was overwhelmed by the richness and diversity of life in the rainforest. He spent much time ashore, based in Montevideo and Buenos Aires, while the Beagle mapped the coast of Argentina. He travelled deep into the rainforest collecting specimens and crossed the Argentinean pampas with the local gauchos. He carefully preserved and packed up hundreds of specimens of plants and animals and shipped them back to England for later study. His discoveries set him thinking about the nature of species and whether they were really unchangeable and had all originated from one divine act of creation.

With Darwin back on board the Beagle, they passed through the Straits of Magellan into the Pacific. While Fitzroy surveyed the cost of Chile, Darwin journeyed high into the Andes by mule and made the startling discovery of layers of fossilised seashells. Geology too was thought to be unchanged since God created it, but Darwin surmised that the Andes must have been slowly pushed up over the aeons of geological time by enormous underground movements. While in Chile, the crew of the Beagle experienced an earthquake that killed nearly a hundred local people. When the shocks had subsided, Darwin noticed that coastal land had risen up by a few feet. If that was possible, numerous quakes over millennia could lift seashells up into the mountains.

The Beagle’s next port of call was the Galapagos Islands, 500 miles off the coast of Ecuador. The crew found the Galapagos to be an inhospitable place, made of black volcanic rock, but Darwin was intrigued by the wildlife there. Each animal was a member of a unique species not seen anywhere else in the world, but all had some striking similarities to specimens he had recently encountered in South America. There were also marked differences between the same type of animal found on different islands of the Galapagos: finches on one island had thick beaks suited to cracking the nuts that grew there, while on another island the finches had long thin beaks suitable for winnowing out insects. Similarly, the giant tortoises that roamed the islands had a different shaped shell if their island had abundant ground vegetation compared to ones on islands dominated by trees.

This got Darwin thinking. What if the Galapagos had been created relatively recently – geologically speaking – by a volcanic eruption and a few plants and animals had managed to fly, swim or drift there from South America. Those unsuited to the conditions on the barren new islands would perish, but if they survived and had offspring they, simply through natural variation, might be better or worse suited to the islands and so have differing chances of survival. In this way, natural variations and the simple process of survival of the fittest gradually created the new species uniquely suited to life on each of the Galapagos Islands.

It was nearly a year later, in October 1836, that the Beagle arrived back in England and so Darwin had had plenty of time to ponder his discoveries and extend his idea. He concluded that all of nature’s diversity, including human beings, must have branched out from a small number of primitive forms in the very distant past. That idea was so radical and contrary to the teachings of the church that Darwin was reluctant to reveal it to the world. He spent 10 years cataloguing his specimens from the voyage of the Beagle and writing a detailed account which was then published. He continued to investigate how species changed by studying the breeding of pigeons and plants that he grew in his garden. He wrote a summary of his theory of evolution and hid it away with instructions to his wife to publish it if he should suddenly die.

Then in 1858, 22 years after the Beagle’s return, his hand was forced when another naturalist, Alfred Russell Wallace, sent him an essay he had written describing the very same ideas. Darwin arranged for both Wallace’s essay and a summary of his own theory to be read out to a meeting of the Linnean Society in London the following month. The event didn’t cause much of a stir at the time, but a year later, 150 years ago, Darwin published On the Origin of Species by Means of Natural Selection. All 1250 copies of the first edition were sold out on the day of publication.

Darwin’s theory split the scientific world and popular opinion. It caused a schism between science and the church. Gradually, over the past century and a half, evolution has come to be accepted by virtually all scientists and it has transformed biology from a science that simply classified and catalogued species to one that understands and can study how species change and adapt to their surroundings. From that has come the science of genetics and modern medicine. It has also influenced geology, archaeology and palaeontology. There are still many people who believe that God created the natural world as it is today, but the amount of scientific evidence now amassed in favour of evolution is hard to dispute.

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On the Origin of Species ends with these lines:

Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been 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.

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To mark Darwin Day, we’ve filled a display case in the Northgate Street entrance to Ipswich County Library with information about Charles Darwin, including the above, and left some leaflets with an evolution reading list. File Attachment: Darwin leaflets.pdf (706 KB) The exhibit will be there until first thing on Monday morning (16^th February).

My thanks to Dan Clery for the introduction to Darwin, to Sharon at Sharward Services for all the last minute printing, and to David Mitchell, Andrew Morrison and Jenness Proctor for helping me to set everything up.

The above poster was made using two copyright-free 19^th century prints. For a full size version to download, click here.

“Man is descended from a hairy, tailed quadruped, probably arboreal in its habits” – Charles Darwin