Darwin's theory of evolution
Photograph of Charles Darwin
Charles Darwin (1809 - 1882)
Charles Darwin was an English naturalist who studied variation in plants and animals during a five-year voyage around the world in the 19th century. He explained his ideas on evolution in a book called, 'On the Origin of Species', published in 1859.
Darwin's ideas caused a lot of controversy, and this continues today, because they can be seen as conflicting with religious views about the creation of the world and the creatures in it.
The basic idea behind the theory of evolution is that all the different species have evolved from simple life forms. These simple life forms first developed more than 3 billion years ago (the Earth is about 4.5 billion years old). The timeline below shows some of the key events in the evolution of life on Earth, from the first bacteria to the first modern humans.