New research  at  the University of Birmingham on Darwin’s Origin of Species, first published in 1859, 150 years ago today, has uncovered the moment when Darwin saw that his thought had changed the world forever. 

Barbara Bordalejo, of the University’s Institute for Textual Scholarship and Electronic Editing at the University, today published online her Variorum Edition of Darwin’s Origin.  To make this edition she compared word-by-word all six British editions of the Origin published in Darwin’s lifetime.  She tracked more than 15,000 changes Darwin made in the five editions after the 1859 edition and studied how Darwin shaped the book according to his developing sense of what he had achieved.

Bordalejo says, ‘My research shows that the most significant changes came as Darwin became more confident in his own theory, and more determined to see that it was understood by others as clearly as possible.  Thus, throughout the five later editions, he removes phrases like “I think”, “I presume”, and tightens up the prose, presenting arguments more decisively and objectively. 

She continues, ‘In effect, his prose changes from that of a gentleman naturalist, to something more like the more impersonal style found in modern scientific publications.  One revised sentence shows when Darwin realized that his idea, which he had been so reluctant to present to the world, had changed the world.  In 1861, for the third edition, he added a ‘Historical Sketch’ at the beginning of the Origin, summarizing the development of his thought. In the second sentence of the 1861 Sketch he wrote

‘The great majority of naturalists believe that species are immutable productions, and have been separately created.’

For the fifth edition in 1869, after he had seen the world debate his ideas for a decade, he changed this:

‘Until recently the great majority of naturalists believed that species were immutable productions, and had been separately created.’

She continues, ‘The break with the past was decisive.  What people used to believe, they no longer believed.  Evolution had arrived, and the world had changed.’

Bordalejo points out that Darwin relied heavily on others to achieve what he did, again foreshadowing the collaborative nature of modern science.  Similarly her edition relied on the work of others, particularly Mark Pallen, Professor of Microbial Genomics at the University and the author of the ‘Rough Guide to Evolution’, and John Van Wyhe, of Darwin Online, which provided the transcripts of the six editions which Bordalejo compared and which hosts the Online Variorum.

The Online Variorum is at


Notes to Editors

Bordalejo’s edition of the Online Variorum of the Origin is the first online edition of the kind, and supersedes the print Variorum pubished by Morse Peckham in 1955?.  It is the first full electronic Variorum of any major English nineteenth-century writer.  It was made without any grant funding.

Barbara Bordalejo is Co-Director of the Institute for Textual Scholarship and Electronic Editing at the University of Birmingham. 

She holds doctorates in early print, medieval English and the application of evolutionary biology methods to the analysis of manuscript traditions.  Her interest in Darwin developed from her study of the publication history of Darwin’s contemporary, the American poet Walt Whitman.

Mark Pallen is  Professor of Microbial Genomics at the University and the author of the ‘Rough Guide to Evolution’.  He ca be contacted by e-mail at

John Van Wyhe is founder and director of Darwin Online, the largest single collection of Darwin materials (copies of his published editions, manuscript materials and other documents) in both image and text form.