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Wallace's 'Sarawak law' paper

Wallace's 'Sarawak law' paper

Catalogue number: WP7/3

Reprint of Wallace's paper On the Law which has Regulated the Introduction of New Species, dated February 1855.

This is a reprint of the first paper in which Wallace publicly mentions evolution. The title is On the Law which has Regulated the Introduction of New Species, but is generally summarised as the 'Sarawak law' paper since Wallace wrote it in 1855 while in the Sarawak region of Borneo.

The core theme is that gradual geological changes are linked to animal and plant distribution. Wallace begins: 'The following propositions in Organic Geography and Geology give the main facts on which the hypothesis is founded'. To support this statement Wallace discusses nine pieces of geographical and geological evidence, and ends with the 'Sarawak law': 'the following law may be deduced from these [preceding] facts:-Every species has come into existence coincident both in space and time with a pre-existing closely allied species.'

This 'law' shows that Wallace understood the result of evolution, but at this early stage he had no model of how it was actually achieved. It was three years before Wallace would develop his evolutionary theory based on natural selection.

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Wallace Letters Online

Letter to Alfred Russel Wallace from the Royal Society, about his Darwin Medal award

View high resolution scans and transcripts of Alfred Russel Wallace's correspondence, including all surviving letters between him and Charles Darwin.

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