New light on The foundations of the origin of species: A reconstruction of the archival record.

Abstract

Between the first formulation of a theory and its mature exposition often lie many years of revision. Such was the case for Charles Darwin's theory of descent. In the six years between 1838, when he first grasped the importance of natural selection, and the composition of the fair copy of the 1844 Essay, Darwin made several attempts to write out his ideas. The general nature of these documents has been known since the publication by Francis Darwin in 1909 of Darwin's 1842 Pencil Sketch and the 1844 Essay.' However, important documentary elements, particularly for the transitional period between the notebooks of the late 1 830s and the Essays of the early 1840s, have remained incomplete and unclear. It is now possible to clarify the record and to reconstruct in detail Darwin's transition from insight to essay. As is well known, Darwin between 1837 and 1839 recorded his speculations on species in a series of four Transmutation Notebooks.2 But it is not well known that loose pages, not yet published, have been found from two later Transmutation Notebooks. Darwin appears to have removed all the pages of interest in these 1839-1842 notebooks and discarded the bindings. Hence we call them his "Torn-Apart Notebooks." The earliest and most important of these, reconstructed by Sydney Smith,3 comprises at least 42 surviving manuscript pages with