Charles Darwin (AD 1809-82) studied to be a clergyman, but had a great enthusiasm for natural history. In 1831 he was invited to join HMS Beagleas official naturalist on a surveying expedition to South America. The voyage was to last for five years and change the way people thought about how life developed on Earth.

Examining fossils, Darwin realised that the geological history of the Ecccarth was one of constant change. On the Galapagos Islands, he found unique species which varied from island to island. He began to think that successful species were those that adapted to their surroundings. Those that did not adapt gradually died out. This theory of natural selection challenged belief in a world created all at once by God. Darwin knew that it would cause outrage, and it was almost 30 years before he published it in Origin of Species by Means of Natural Selection(1859).

The reaction was predictably hostile, but the biologist T.S. Huxley (1825-95) made a powerful defence of Darwin’s ideas in 1860. After that, public opinion gradually came to accept Darwin’s theory of evolution, although many believers continued to deny it. In 1872, when Darwin published The Descent of Man, which suggested that man and apes were descended from a common ancestor, it was received without an outcry.