The naturalist Charles Darwin was born 203 years ago today, Darwin Day.

In his book, On the Origin of Species, Darwin set out what is probably the most important idea in the history of science. He reasoned that plants, animals and all living things are not static and unchanging, remaining as they were made by a divine creator; instead they change subtly from one generation to the next and those that are better suited to whatever environment they find themselves in prosper and reproduce more, while those that are less well suited dont. In this way, plants and animals gradually change, eventually developing into new species and producing the huge variety of nature that we see today. Darwins theory, evolution by natural selection, is at the root of our understanding about life on Earth: it explains why there is such diversity in nature, why we are here, and why we are as we are.

On the Origin of Species was published in 1859, yet there are still many who reject evolution as an explanation for how we came to be here, prefering the Biblical story of Genesis or another creation myth – there are many – and there are still too many children leaving school ignorant of the theory of evolution.

For more on evolution and ‘Intelligent Design’ (Creationism in another form) click here for our article, We’re all Monkeys.

The illustration is a montage of two 19th century prints, of a chimpanzee and Charles Darwin. Modern science has confirmed Darwin’s theory that human beings and apes had a common ancestor. It lived between 5 and 8 million years ago, and we share 96% of our genetic material with our closest living relatives, the chimps.

The first paragraph above is taken from Dan Clery‘s introduction to Darwin, written for our 2009 Darwin Day exhibition.