Page 58 - Science Coursebook

3.8 Charles Darwin

Charles Darwin was born in Shrewsbury, in England, in
1809. Although he trained to be a doctor, he always had
a great interest in the natural world around him. He was
very observant, and made records of many of the plants
and animals that he saw in his garden and on his travels.
Darwin corresponded with many other scientists, with
whom he remained friends for much of his life. One of
these was Charles Lyell. In 1830, Lyell published a book
called Principles of Geology. In this book, Lyell suggested
that the mountains and valleys that we see today have
not always been there, and they will change in the future.
Lyell also thought that the fossils which people found in
rocks were remains of different kinds of organisms that

had lived millions of years ago. These were both new
ideas. Most people thought that rocks and species were
unchanging.

In 1831, Charles Darwin began a five-year voyage as the
naturalist on board the ship The Beagle. He visited many A portrait of Charles Darwin made in
countries in South America, as well as the Galapagos 1840, when he was 31 years old.

Islands in the Pacific Ocean. He took Lyell’s book
with him. He began to think that, if mountains and
rocks could change over time, then perhaps species of
organisms could change, too.
Darwin was particularly interested in the species of birds
that he saw in the Galapagos Islands. Each island seemed
to have its own set of species, and most of the species
were slightly different on each island. Each finch was

adapted for a slightly different lifestyle. For example, some

had thick, strong beaks for eating large seeds, while others
had thinner beaks, better for eating small seeds or insects. An engraving of The Beagle, sailing through
the Straits of Magellan.
When he eventually arrived home, Darwin began to
develop an idea. Perhaps all of the different species of

finches on the different islands in the Galapagos had

developed from one original species. But at first he could

not work out how this could have happened.
In 1855, Darwin took up pigeon breeding. This was a
popular hobby in England. Many different varieties of

pigeons had been produced, but no-one had kept records
of where they all came from. Darwin had the idea that
they had all been developed from a species of wild
pigeon, the rock dove. He began to see a way in which

the different species of finches on the Galapagos Islands Darwin thought that all of these different

might have developed. species of finches might all have come from
the same ancestor.
56 3 Variation and inheritance

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