I'm Steve Ember.
I'm Barbara Klein with EXPLORATIONS in VOA Special English. This month is the two hundredth anniversary
of the birth of one of the most influential thinkers in science history. Charles Darwin developed the theory of how living
things develop from simpler organisms over long periods of time. That theory is known as evolution through
do new kinds of life come into existence?
For much of recorded history, people have believed that organisms were
created. Few people believed that living
things changed. What process could make
such change possible?
were some of the questions Charles Darwin asked himself over years of research
in botany, zoology and geology. He was
not the first person to ask them. His
own grandfather, Erasmus Darwin, believed that species evolved. And others, like the French naturalist
Jean-Baptiste Lamark, had proposed ways this could happen. But it was Darwin who identified and explained
the process, natural selection, that causes life to evolve.
Charles Darwin was
born in Shrewsbury, England on February twelfth, eighteen-oh-nine. His father
Robert Darwin was a doctor. Charles'
mother Susannah Darwin was the daughter of the famous potter, Josiah
Wedgwood. She died when Charles was only
eight years old.
Young Charles was
intensely interested in the natural world from an early age. But his father wanted him to be a
age sixteen, Charles was sent to study medicine at the University of
Edinburgh. But he did not like it. He found medical operations especially horrible. He later went to Cambridge University. His father now hoped that Darwin would become
a clergyman. But at Cambridge, Charles continued to follow his own
interests. There, he met John Henslow, a
plant scientist and clergyman. The two
Henslow suggested that Charles Darwin take the unpaid position of naturalist for
a trip on the British ship H.M.S. Beagle. It sailed around the world from
eighteen thirty-one to eighteen thirty-six. The main goal was to make maps of
the coastline of South America. The
British government paid for the voyage.
But another purpose of the trip was to collect scientific objects from
around the world.
The Beagle's first stop was one of the
Cape Verde Islands near the coast of Africa.
There, Darwin noted that levels of rock extending high above the sea
contained the fossil remains of shells.
He thought that this was evidence that the bottom of the ocean had been
lifted up by powerful geological forces over long periods of time.
Beagle continued to the coast of South America.
In Valdivia, Chile, Darwin experienced an earthquake. He collected examples of plants and
animals. He also collected the fossil
remains of animals that had disappeared from the Earth.
But it was on the Galapagos Islands off the coast of
Ecuador that Darwin found creatures that made him wonder about how species
develop and change. There, he saw giant
tortoises and noted that the reptiles were different on each island.
collected birds, each with different beaks.
Later, after he had returned to England, he would be shocked to find
that these very different birds were all finches. Darwin found lizards called
iguanas that lived on land and ones that fed in the sea.
noted that all these species were similar to those found in South America. But, they all had differences, or
adaptations, that helped them survive in the environment of the Galapagos Islands.
sent much of what he collected back to England on other ships the Beagle met
along the way. By the time he returned
to England in October of eighteen thirty-six, he was already a well known geologist
and naturalist. Within a few years, he
would be accepted into scientific organizations like the Geological Society and
the Royal Society.
Darwin moved to
London to be near other scientists. He
wrote a new version of the book about his travels. He also edited works of others about the things
he had collected on his trip. Darwin
also agreed to write several books including the "Zoology of the Voyage of
the H.M.S. Beagle." But in eighteen
thirty-seven, the pressure of the work caused his health to suffer. He developed problems with his heart.
Charles Darwin had poor health much of his life. He suffered headaches and problems with his
skin and stomach. No one was able to
find out what disease he may have had during his lifetime. Recently, some experts have suggested that he
might have become infected with a tropical disease. Others suggest Darwin's health problems were
caused by conflict in his mind over his theory.
Poor health would later force him to leave London and settled at Down
House near Kent, England.
began work on a series of secret notebooks containing his thoughts about the evolutionary
process. He began to think that animals
developed from earlier, simpler organisms.
As early as eighteen thirty-seven, he imagined this process as a tree
with branches representing new species.
Unsuccessful branches ended. But
successful evolutionary changes continued to form new branches.
Darwin's personal life was also expanding.
In eighteen thirty-nine, he married Emma Wedgwood, his cousin. He told her his ideas about how species
evolve over time -- what he called the transmutation of species.
Emma did not agree with her husband. But the two had a strong and happy marriage. They had ten children together. Seven of them
Darwin read widely and sought ideas from other fields of study. He was influenced by Thomas Malthus' work,
"An Essay on the Principle of Population" written in seventeen
ninety-eight. Malthus argued that populations are always limited by the food
Darwin would later say that this work caused
him to realize the struggle for limited resources was a fact of life. He said small changes took place in
individual animals. Changes that helped them
survive would continue. But those that
did not would be destroyed. The result of this would be the formation of new
The British philosopher Herbert Spencer described this
struggle as "survival of the fittest." But biologists use the term "natural
selection" to describe the evolutionary process.
Charles Darwin developed his idea slowly over more than
twenty years. He was concerned that he
would lose the support of the scientific community if he revealed it. He wrote to his friend, botanist Joseph
Hooker, that speaking about evolution "was like confessing a murder."
was not until eighteen fifty-eight that Darwin was forced to release his theory
to the public. Another naturalist,
Alfred Russel Wallace, had independently written a paper that contained ideas
similar to Darwin's concerning evolution.
Wallace had reached these ideas from his studies on islands in the western
With help from Darwin's friends, the two naturalists
presented a joint scientific paper to the Linnean Society of London in July of
eighteen fifty-eight. At first there was
in November, eighteen fifty-nine, Darwin released the results of all his work
on evolution. The book was called
"On the Origin of Species by Means of Natural Selection, or the
Preservation of Favoured Races in the Struggle for Life." It was an immediate success.
The "Origin of Species" was praised
by many scientists. But religious
leaders denounced it. For them,
evolution opposed the explanation of creation found in the book of Genesis in
the Bible. Today, almost all scientists
accept the theory of evolution. But many
non-scientists are unsure about whether humans evolved over millions of years. In
the United States, public opinion studies have shown that less than half the
population believes in evolution.
selection does not explain everything about why species evolve. Darwin did not know about Gregor Mendel's
work on heredity. And the discovery of
genetics and D.N.A. molecules took place long after his death. Yet, Darwin theorized in a world much
different from the one we know. That is
why scientists today wonder at the depth of his knowledge and the strength of
died on April nineteenth, eighteen eighty-two.
He was buried at Westminster Abbey, in London, among other heroes of
program was written and produced by Mario Ritter. I'm Barbara Klein.
I'm Steve Ember. You can find a link to Charles
Darwin's writings and research at our Web site, voaspecialenglish.com. Join us again next week for Explorations in
VOA Special English.