Digital facsimile from Google Books at this link.

Wallace's first book, printed in an edition of only 250 copies. Digital facsimile from the Internet Archive at this link.

This paper is sometimes referred to as the Sarawak Law paper since it was written while Wallace was on a specimen collecting expedition in the province of Sarawak (East Malayasian States) on the great island of Borneo. The paper has been misrepresented by certain historians as presenting a portion of the theory of natural selection. That is false; Wallace did not publish on natural selection until the Darwin-Wallace papers published in 1858 (No. 219).

The "law" states "The following law may be deduced from these facts: — Every species has come into existence coincident both in space and time with a pre–existing closely allied species."  

About this Malcolm Jay Kottler wrote to me in April, 2023, "Darwin did not see that Wallace was thinking in evolutionary terms in this paper. In his paper Wallace used the word 'created' a number of times--such as 'It is evidently possible that two or three distinct species may have had a common antitype, and that each of these may again have become the antitypes from which other closely allied species were created"--which Darwin interpreted as creationist, and not evolutionary, in meaning.

See John van Wyhe, "The impact of A. R. Wallace's Sarawak Law paper reassessed," Studies in History and Philosophy of Science Part: Studies in History and Philosophy of Biological and Biomedical Sciences, 60 (2016) 56-66.

The first printed exposition of the “Darwinian” theory of evolution by natural selection. Had not Wallace independently discovered the theory of natural selection, it is possible that the extremely cautious Darwin might never have published his evolutionary theories during his lifetime. However, Wallace conceived the theory during an attack of malarial fever in Ternate in the Mollucas (February, 1858) and sent a manuscript summary to Darwin, who feared that his discovery would be pre-empted. In the interest of justice Joseph Dalton Hooker and Charles Lyell suggested joint publication of Wallace’s paper, On the tendency of varieties to depart indefinitely from the original type, prefaced by a section of a manuscript of a work on species written by Darwin in 1844, when it was read by Hooker, plus an abstract of a letter by Darwin to Asa Gray, dated 1857, to show that Darwin’s views on the subject had not changed between 1844 and 1857.

The Darwin-Wallace paper was issued in five different forms, all from the same setting of type. Four of these resulted from the publishing customs of the Linnean Society of London, which issued the journal in three different printed wrappers, depending on whether members subscribed to the zoological or botanical parts alone or both parts together. The fourth form was publication in the annual volume of the Journal, "made up from reserved stock of the parts with new title pages, dated in the year of completion of the volume, and indexes. This again was available complete or as Zoology or Botany alone" (Freeman). The fifth form was the authors' offprint. That form is of the greatest rarity.

Wallace delivered this paper to the polygenist Anthropological Society of London on 1 March 1864. It represents “the first effort to connect natural selection to the touchy problem of the evolution of human races” (Wallace 1991, 26), a topic that Huxley broached in his Evidence of Man's Place in Nature (1863) but which Darwin avoided until his Descent of Man (1871).

Wallace argued that man is fundamentally different from all other species because of the nature of the human mind, which enabled him “to remove his body from the modifying influence of external conditions, and the cumulative action of natural selection.” Though Wallace shares credit with Darwin for the theory of evolution by natural selection, Wallace differed fundamentally from Darwin in his attempt to distinguish the effect of natural selection upon man from its effect on the rest of living things. 

Reprints, with important revisions and additions, nine important papers concerning natural selection, which had previously appeared in journals, and publishes for the first time a major paper on The limits of natural selection as applied to man. Unlike Darwin, Wallace believed that at some point during man’s history man had partially escaped natural selection, and that a “higher intelligence” had a part in the development of the human race.

"In 1872, at the urging of many of his friends, including Darwin, Philip Sclater, and Alfred Newton, Wallace began research for a general review of the geographic distribution of animals. He was unable to make much progress initially, in part because classification systems for many types of animals were in flux at the time.^[120] He resumed the work in earnest in 1874 after the publication of a number of new works on classification.^[121] Extending the system developed by Sclater for birds—which divided the earth into six separate geographic regions for describing species distribution—to cover mammals, reptiles and insects as well, Wallace created the basis for the zoogeographic regions still in use today. He discussed all of the factors then known to influence the current and past geographic distribution of animals within each geographical region. These included the effects of the appearance and disappearance of land bridges (such as the one currently connecting North America and South America) and the effects of periods of increased glaciation. He provided maps that displayed factors, such as elevation of mountains, depths of oceans, and the character of regional vegetation, that affected the distribution of animals. He also summarised all the known families and genera of the higher animals and listed their known geographic distributions. The text was organised so that it would be easy for a traveller to learn what animals could be found in a particular location. The resulting two-volume work, The Geographical Distribution of Animals, was published in 1876 and would serve as the definitive text on zoogeography for the next 80 years.^[122]

"In this book Wallace did not confine himself to the biogeography of living species, but also included evidence from the fossil record to discuss the processes of evolution and migration that had led to the geographical distribution of modern animal species. For example, he discussed how fossil evidence showed that tapirs had originated in the Northern Hemisphere, migrating between North America and Eurasia and then, much more recently, to South America after which the northern species became extinct, leaving the modern distribution of two isolated groups of tapir species in South America and Southeast Asia.^[123] Wallace was very aware of, and interested in, the mass extinction of megafauna in the late Pleistocene. In The Geographical Distribution of Animals (1876) he wrote, "We live in a zoologically impoverished world, from which all the hugest, and fiercest, and strangest forms have recently disappeared".^[124] He added that he believed the most likely cause for the rapid extinctions to have been glaciation...." (Wikipedia article on Alfred Russel Wallace, accessed 02-2017).

"In 1880, Wallace published the book Island Life as a sequel to The Geographical Distribution of Animals. It surveyed the distribution of both animal and plant species on islands. Wallace classified islands into three different types. Oceanic islands, such as the Galapagos and Hawaiian Islands (then known as the Sandwich Islands) formed in mid-ocean and never part of any large continent. Such islands were characterised by a complete lack of terrestrial mammals and amphibians, and their inhabitants (with the exceptions of migratory birds and species introduced by human activity) were typically the result of accidental colonisation and subsequent evolution. He divided continental islands into two separate classes depending on whether they had recently been part of a continent (like Britain) or much less recently (like Madagascar) and discussed how that difference affected the flora and fauna. He talked about how isolation affected evolution and how that could result in the preservation of classes of animals, such as the lemurs of Madagascar that were remnants of once widespread continental faunas. He extensively discussed how changes of climate, particularly periods of increased glaciation, may have affected the distribution of flora and fauna on some islands, and the first portion of the book discusses possible causes of these great ice ages. Island Life was considered a very important work at the time of its publication. It was discussed extensively in scientific circles both in published reviews and in private correspondence^{[126]" (Wikipedia article on Alfred Russel Wallace, accessed 02-2017).}

The first serious attempt by a biologist to evaluate the likelihood of life on other planets. Wallace concluded that the Earth was the only planet in the solar system that could possibly support life, mainly because it was the only one in which water could exist in the liquid phase. More controversially, Wallace maintained that it was unlikely that other stars in the galaxy could have planets with the necessary properties, as the existence of other galaxies had not yet been proved. 

"His treatment of Mars in this book [Man's Place in the Universe] was brief, and in 1907, Wallace returned to the subject with a book Is Mars Habitable? to criticise the claims made by Percival Lowell that there were Martian canals built by intelligent beings. Wallace did months of research, consulted various experts, and produced his own scientific analysis of the Martian climate and atmospheric conditions.^[130] Among other things, Wallace pointed out that spectroscopic analysis had shown no signs of water vapour in the Martian atmosphere, that Lowell's analysis of Mars's climate was seriously flawed and badly overestimated the surface temperature, and that low atmospheric pressure would make liquid water, let alone a planet-girding irrigation system, impossible.^[131] Richard Milner comments: "It was the brilliant and eccentric evolutionist Alfred Russel Wallace ... who effectively debunked Lowell's illusionary network of Martian canals."^[132]Wallace originally became interested in the topic because his anthropocentric philosophy inclined him to believe that man would likely be unique in the universe^{[133] (Wikpedia article on Alfred Russel Wallace, accessed 02-2017).}

Digital facsimile from Google Books at this link.

"Wallace's comments on environment grew more strident later in his career. In The World of Life (1913) he wrote:

"These considerations should lead us to look upon all the works of nature, animate or inanimate, as invested with a certain sanctity, to be used by us but not abused, and never to be recklessly destroyed or defaced. To pollute a spring or a river, to exterminate a bird or beast, should be treated as moral offences and as social crimes; ... Yet during the past century, which has seen those great advances in the knowledge of Nature of which we are so proud, there has been no corresponding development of a love or reverence for her works; so that never before has there been such widespread ravage of the earth's surface by destruction of native vegetation and with it of much animal life, and such wholesale defacement of the earth by mineral workings and by pouring into our streams and rivers the refuse of manufactories and of cities; and this has been done by all the greatest nations claiming the first place for civilisation and religion!^{[129] "(Wikipedia article on Alfred Russel Wallace, accessed 02-2017).}

"Our project has so far obtained electronic copies of 5,688 letters, of which 2,748 were written by Wallace and 2,159 were sent to him. The remaining 781 are third party letters which either pertain to him, or were written by Wallace's close relatives and contain information useful to scholars interested in his life. The letters were found in 245 public and private collections around the world, and in 245 articles and books" (accessed 10-2021).

http://wallace-online.org/

"Wallace Online is the first complete edition of the writings of naturalist Alfred Russel Wallace, including the first compilation of his specimens. The project is directed by John van Wyhe, assisted by Kees Rookmaaker, at the National University of Singapore, in collaboration with the Wallace Page by Charles H. Smith.

Biography

Illustrations

Wallace in Singapore

About the project

Acknowledgements

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