On the Origin of Species is Darwin's greatest work—his theory of evolution by natural selection.

The bite-sized version is about 14% of the total text of the original 1859 edition. It is a section by section account which summarises each significant point. In order to retain Darwin’s voice, his turn of phrase is often used but clarified where necessary. Notable quotations are included to convey an even stronger sense of the original. Students and those with an interest in exploring Darwin’s writing will find the essence of his thinking contained in this concise account of his greatest work. Darwin scholars may usefully read the bite-sized edition in tandem with the original work. A short introduction provides a contemporary context for Darwin's Origin.

Over the last 150 years Darwin's ideas have infiltrated and shed light on all the life sciences, reaching out as recently as the past decade to rejuvenate microbiology and parasitology. Yet Darwin's theory remains almost as controversial today as it was in his lifetime, particularly with regard to the teaching of intelligent design in schools. Strange though it may seem from this perspective, Darwin’s work owes much to the divine interpretation of nature which was prevalent in the Church establishment and society at large in Britain in the early 19th century. The Church’s position on nature was so deeply set, so detailed in its understanding, and so universally accepted, that no alternative could hope to challenge it unless rigorously grounded in careful observation and scientific thought. Darwin had to get it right or risk being unmercifully hounded and exposed. Is it any wonder that he waited 21 years from his pivotal insight into evolution before publishing the idea in his Origin of Species and, even then, only when spurred on by the parallel thinking of Alfred Russell Wallace?