The captain of the ship, the Beagle, wanted someone who would "profit by the opportunity of visiting distant countries yet little known". The person who answered the call was not the captain's first choice. It was a young man who had left medical school without completing his degree. What's more, he had recently received a letter from his father predicting that he would be "a disgrace to yourself and all your family". Despite all this, his adventures on this ship would lead to one of the most important scientific discoveries of all time.
The young man in question, Charles Darwin, was a geologist and naturalist, fascinated by rocks, plants and animals. The journey gave him the chance to study various living things in their natural environments. After Darwin had spent some time in South America, his room on the ship was crowded with samples of the plants and animals he had collected. As he studied these, he asked himself the question: how did different species come to exist?
At that time, people believed that all species had appeared on Earth at the same time, and had not changed since. But Darwin began to think differently. He noticed that some species of animals were very similar to each other. Maybe animals evolved as they adapted to their changing environments. It was just an idea, but enough to inspire Darwin to look for more evidence. When the Beagle reached the Galapagos Islands in 1835, Darwin saw a variety of new species, but it was the birds that interested him the most. Darwin noticed that there was a difference between the finches (雀科小鸟) on each of the islands. It seemed their beaks (鸟喙） had evolved according to what food was available on that particular island.
Darwin suspected the finches had evolved from a common ancestor, which had arrived on the islands a long time before. Over time, it had slowly evolved into many new species. And that was the answer to how new species of plants and animals came to exist: they evolved from earlier ancestors.
It was a completely new idea — a theory of evolution. Darwin explained this theory in his book, On the Origin of Species. Many people refused to believe that living things, including humans, had evolved from lower forms of life. But Darwin's scientific studies were so convincing that more and more people started to believe his theory.
Today, On the Origin of Species has changed ideas about life on Earth forever. And it all began with the journey on the Beagle.
