Alfred Russel Wallace
Alfred Russel Wallace (b. January 8, 1823; d. November 7, 1913), British naturalist, field biologist, evolutionary biologist, biogeographer, humanist, anthropologist, social and political critic, and prolific writer—proposed, and described in manuscript, the process of natural selection as a mechanism of biological evolution before Charles Darwin (b. February 12, 1809; d. April 19, 1882) published the same concept in his revolutionary book, On the Origin of Species.
Although Darwin's work overshadowed Wallace's for many decades, now many biologists argue for a more informed and celebrated acknowledgment of Wallaces's contributions to our understanding of evolution and to his pioneering work establishing the field of biogeography. 
Wallace greatly admired and strongly supported his co-discoverer of natural selection, Charles Darwin. He differed from Darwin regarding the best way to describe the evolutionary principle, preferring the phrase 'survival of the fittest'. He and Darwin differed also regarding the relationship between artificial and natural selection; on the importance of sexual selection; and, on the application of the evolutionary principle to the origin of the human mental faculties.
Often represented as an eccentric outsider, espousing spiritualism and socialism, opposing vaccination, Wallace actually resonated with much of mainstream Victorian cultural displeasure with the accelerating trend to materialism. He received praise widely for his books describing his travels and explorations of the Amazon and Indonesia (the Malay peninsula). In all his books, those expeditionary works and his political and social treatises, his love of the wonders of the natural world and deep-rooted humanity stood sharply out.
Like Darwin, Wallace, 14 years Darwin's junior, possessed a passionate and inveterate desire to observe the natural world of plants and animals, both in England and in the biologically unexplored wilds of the world — the Malay Archipelago;  the Amazon River valley. Wallace distinguished himself as a prolific explorer-naturalist. Also like Darwin, inspired by the political economist, Thomas Malthus (1766-1834) and Malthus's ideas about the limits of population growth due to the limits of growth-supporting resources in the environment, Wallace concluded that nature selected for reproductive success those individuals of an interbreeding population with heritable traits enabling them to best cope with a changing environment that threatened their ability to generate progeny — viz., the principle of natural selection, or, as Wallace preferred to call it, 'survival of the fittest'. Wallace developed the idea independently of Darwin, though not before Darwin had many years earlier worked out the idea in great detail, but before Darwin had published his discovery except in private communications with a few colleagues. Fortunately for both Darwin and Wallace, Darwin's colleagues arranged for a joint reading of Wallace's manuscript and Darwin's earlier unpublished manuscript that he had shared with a few colleagues.
In a speech by the eminent British evolutionary biologist, Richard Dawkins, given November 26th, 2001, for the unveiling of a plaque in the Royal Academy commemorating the concurrent reading of the Darwin’s and Wallace’s first public papers describing natural selection, at a meeting of England’s Linnean Society, July 1st, 1858, Dawkins stated:
Not only is it [natural selection] the all-but universally accepted explanation for all the complexity and elegance of life. It is also, I strongly suspect, the only explanation that in principle could provide that explanation. But Darwin was not the only person who thought of the idea. When Professor [Daniel] Dennett and I made our remarks, we were — certainly in my case and I suspect that Dennett would agree — using the name Darwin to stand for “Darwin and Wallace”. This happens to Wallace quite often, I am afraid. He tends to get a poor deal at the hands of posterity, partly through his own generous nature. It was Wallace himself who coined the word ‘Darwinism’, he regularly referred to it as Darwin’s theory and he referred to himself as ‘more Darwinian than Darwin’. The reason we know Darwin’s name more than Wallace’s is that Darwin went on, a year later, to publish the Origin of Species. The Origin not only explained and advocated the Darwin/Wallace theory of natural selection as the mechanism of evolution. It also – and this had to be done at book length – set out the multifarious evidence for the fact of evolution itself.
Nevertheless, Wallace and Darwin had different perspectives on natural selection and the mechanisms of evolution, which this article will in part explore. Moreover, Wallace pursued many other interests, and wrote books on biogeography, anthropology, mimicry, social and economics issues, physical geography, geology, evolution, and spiritualism — which this article will also explore.
Wallace's early life
We know of Wallace's early circumstances from his autobiography published in 1905, Wallace in his eighties when he wrote it. Wallace entered life in the country town Usk, built near a river of that name, in Monmouthshire, in southern Wales, in 1823, as a member of a family of modest means, the eighth of nine children, all of whom he survived. In his 1905 autobiography, he explained, in the termniology of the pseudoscience, phrenology — a popular 'science' then and persisting in places for decades later — his failure while at Usk (until age 5 years) to create distinct visual memories of his parents or siblings but quite distinct images of the outdoors:
The shape of my head shows that I have form and individuality but moderately developed, while locality, ideality, colour, and comparison are decidedly stronger. Deficiency in the first two caused me to take little notice of the characteristic form and features of the separate individualities which were most familiar to me, and from that very cause attracted less close attention ; while the greater activity of the latter group gave interest and attractiveness to the ever-changing combinations in outdoor scenery, while the varied opportunities for the exercise of the physical activities, and the delight in the endless variety of nature which are so strong in early childhood, impressed these outdoor scenes and interests upon my memory. 
As a young child at Usk, he had a recurring nightmare (attack by a house-sized bird with large claws), not as bad nightmares as many he had later during his lifetime. At that time he had light flaxen hair and a fair body (a “little Saxon” by Welsh norms). He remained healthy, which he attributed to vigorous physical activity in a underdeveloped wilderness surrounding the house he lived in. By age six, the family had moved to Hertford, a larger town, where Wallace spent most of his boyhood, becoming increasingly familiar with the natural world of rivers and woodlands and meadows and at the same time curious about the workings of large machines and factories evolving with the industrial revolution. Did he sense ‘survival of the fittest’ machines as a boy? He did note how technological innovations for the convenience of an ever-growing population could destroy the natural beauty of the wild world.
He attended The Grammar School in Hertford, a large one-room school with eighty boys divided among several ‘masters’ (teachers) kept organized by an irascible headmaster. Wallace toiled at learning Latin grammar, and translating the Latin classics. Geography he found painful because it consisted mostly of rote memorization of place names:
It was something like learning the multiplication table both in the painfulness of the process and the permanence of the results. The incessant grinding in both, week after week and year after year, resulted in my knowing both the product of any two numbers up to twelve, and the chief towns of any English county so thoroughly, that the result was automatic, and the name of Staffordshire brought into my memory Stafford, Litchfield, Leek, as surely and rapidly as eight times seven brought fifty-six. The labour and mental effort to one who like myself had little verbal memory was very painful, and though the result has been a somewhat useful acquisition during life, I cannot but think that the same amount of mental exertion wisely directed might have produced far greater and more generally useful results.
His ability to memorize would hold him in good stead as a wage-earning naturalist.
While living and schooling at Hertford from the ages of 6 to 14 years, Wallace read widely and avidly, books available to his father as a member of a book club and as a librarian for a proprietary library. His parents practiced “old-fashioned” religion as members of the Church of England, but often attended meetings of other congregations. Apparently religion did not take with Wallace, as he writes in his autobiography:
....the Dissenters' chapel was always a welcome change, and we went there not unfrequently to the evening service. The extempore prayers, the frequent singing, and the usually more vigorous and exciting style of preaching was to me far preferable to the monotony of the Church service; and it was there only that, at one period of my life, I felt something of religious fervour, derived chiefly from the more picturesque and impassioned of the hymns. As, however, there was no sufficient basis of intelligible fact or connected reasoning to satisfy my intellect, this feeling soon left me, and has never returned.
After Hertford, Wallace’s parents sent him to London to live temporarily with his 19-year-old brother John, apprenticed as a carpenter. John introduced him to London life among the working class, whence he learned of the founder of the socialist movement in England (1830s), Robert Owen, read and admired his writings, and read other works on the principles of "secularism or agnosticism, as it is now called." Wallace started on the path to utopian socialism. "I also received my first knowledge of the arguments of sceptics, and read among other books Paine's "Age of Reason."" He clearly asserted his religious skepticism at this time:
I therefore thoroughly agreed with Mr. Dale Owen's [Robert Owen's son] conclusion, that the orthodox religion of the day was degrading and hideous, and that the only true and wholly beneficial religion was that which inculcated the service of humanity, and whose only dogma was the brotherhood of man. Thus was laid the foundation of my religious scepticism.
After a short period with his brother John, Wallace moved again, to apprentice as a land-surveyor with an older brother, William, with whom he learned of the science of geology, of fossils, and the basics of surveying, including the use of trigonometry, during the years 1837-1843 (aged 14-20). As part of his job he had to collect rents from tenant farmers with whom he sympathized with their poverty.
In 1844 Wallace acquired a teaching position. He began to read books about phrenology and found himself attracted to the new approach to understanding the human mind, adapting his own thinking in a way that would eventually influence his thoughts on the role, or non-role, of natural selection in human evolution.
In 1848 (age 25) he traveled with a naturalist friend to the Amazon, and in 1854 (age 31) he traveled to the Malay peninsula, collecting specimens of flora and fauna from many islands, and found himself thinking about the evolution of species.
Wallace conceives the concept of Natural Selection
In 1858 (age 35), between episodes of malarial fever, Wallace remembered the essay by Thomas Malthus on the limits of population growth attributable to growth-supporting resource limitations. The essay had the same effect on him as it had earlier on Darwin, inspiring him to conceive the principle of natural selection. Though he had earlier corresponded with Darwin, he had no knowledge of Darwin's prior discovery (1838) of the principle.
Wallace sent a brief summary of his thoughts to Darwin, who found himself stunned to learn that Wallace had independently discovered the principle of natural selection that he, Darwin, had nurtured without publication for the previous 20 years. Darwin's colleagues, with whom Darwin had shared his thoughts, advised that they submit Wallace's paper along with a sketch by Darwin for concurrent reading and publication by the Linnean Society of London, which occurred in July, 1858.
Wallace subsequently acknowledged Darwin's priority and later referred to the theory of evolution by means of natural selection as "Darwinism", having coined the term and written a book with that title.
Comparison of Wallace’s and Darwin’s thoughts on 'natural selection'
Darwin considered Wallace’s 'theory' of natural selection nearly exactly the same as his own. With few exceptions, most biologists would agree. Kutschera, however, performed a careful comparative analysis of the Wallace’s and Darwin’s first published papers on the subject, those read before the Linnean Society in 1858, and he summarized several important differences:
- Whereas Darwin emphasized the resemblance of domestic varieties produced by artificial selection, and used that fact in constructing his argument for natural selection, Wallace considered domestic varieties as “abnormal” and not “model systems” for natural animals. (Indeed, modern biologists have noted that in many cases domestic breeds suffer reduced reproductive fitness.) Wallace writes:
One of the strongest arguments which have been adduced to prove the original and permanent distinctness of species is, that varieties produced in a state of domesticity are more or less unstable, and often have a tendency, if left to themselves, to return to the normal form of the parent species; and this instability is considered to be a distinctive peculiarity of all varieties, even of those occurring among wild animals in a state of nature, and to constitute a provision for preserving unchanged the originally created distinct species….It will be observed that this argument rests entirely on the assumption, that varieties occurring in a state of nature are in all respects analogous to or even identical with those of domestic animals, and are governed by the same laws as regards their permanence or further variation. But it is the object of the present paper to show that this assumption is altogether false, that there is a general principle in nature which will cause many varieties to survive the parent species, and to give rise to successive variations departing further and further from the original type, and which also produces, in domesticated animals, the tendency of varieties to return to the parent form…..Let us now turn to domesticated animals, and inquire how varieties produced among them are affected by the principles here enunciated. The essential difference in the condition of wild and domestic animals is this,—that among the former, their well-being and very existence depend upon the full exercise and healthy condition of all their senses and physical powers, whereas, among the latter, these are only partially exercised, and in some cases are absolutely unused. A wild animal has to search, and often to labour, for every mouthful of food—to exercise sight, hearing, and smell in seeking it, and in avoiding dangers, in procuring shelter from the inclemency of the seasons, and in providing for the subsistence and safety of its offspring. There is no muscle of its body that is not called into daily and hourly activity; there is no sense or faculty that is not strengthened by continual exercise. The domestic animal, on the other hand, has food provided for it, is sheltered, and often confined, to guard it against the vicissitudes of the seasons, is carefully secured from the attacks of its natural enemies, and seldom even rears its young without human assistance. Half of its senses and faculties are quite useless; and the other half are but occasionally called into feeble exercise, while even its muscular system is only irregularly called into action.
- Whereas Darwin included animals and plants in enunciating natural section in his Linnean paper, Wallace cites only animals.
- Whereas Darwin stressed the effects of competition predominantly among members of the same species, Wallace stressed threats from the environment, whether non-living or living, including other species. Wallace writes:
The powerful retractile talons of the falcon- and the cat-tribes have not been produced or increased by the volition of those animals; but among the different varieties which occurred in the earlier and less highly organized forms of these groups, those always survived longest which had the greatest facilities for seizing their prey. Neither did the giraffe acquire its long neck by desiring to reach the foliage of the more lofty shrubs, and constantly stretching its neck for the purpose, but because any varieties which occurred among its antitypes with a longer neck than usual a once secured a fresh range of pasture over the same ground as their shorter-necked companions, and on the firs scarcity of food were thereby enabled to outlive them. Even the peculiar colours of many animals, especially insects, so closely resembling the soil or the leaves or the trunks on which they habitually reside, are explained on the same principle; for though in the course of ages varieties of many tints may have occurred, yet those races having colour. best adapted to concealment from their enemies would inevitably survive the longest.
- Whereas Darwin endorsed Lamarck’s evolutionary mechanism of the inheritance of acquired characteristics, Wallace rejected it as unnecessary
- Whereas Darwin emphasized the importance of long periods of (geologic) time for natural selection to yield new species, Wallace did not bring the issue up.
- Whereas Darwin introduced the concept of sexual selection as part of the evolutionary process, Wallace did not appear to have conceived it.
- Whereas Darwin used the term “natural section”, Wallace did not, though he did outline the process and used terms like “adaptation” and “population” in ways modern biologists do today.
In comparing Wallace’s and Darwin’s views as articulated in their companion Linnean initial publications of 1858, we ignore the future refinements of their thinking and how they might compare and contrast. On one point, and not a peripheral one, Darwin never did arrive at a cogent definition of “species”, emphasizing the difficulties in distinguishing varieties from species. Wallace, however, made several stabs at making the distinction.
Wallace's response to the Hooker-Lyell solution of a joint presentation to the Linnean Society in 1858
Wallace showed no evidence of distress at learning of Darwin’s priority or of the joint presentation of Darwin's and Wallace's papers to the Linnean Society, and graciously accepted it, as Nigel Williams reports, reminding us that July, 2008, will mark the 150 anniversary of the Linnaen Society readings: 
By October, Hooker had received a letter from Wallace concerning the events earlier that year. Wallace expressed gratitude for the way Hooker and Lyell had handled the manuscript. “Allow me in the first place sincerely to thank yourself and Sir Charles Lyell for your kind offices on this occasion and to assure you of the gratification afforded me both by the course you have pursued and the favourable opinions of my essay which you have so kindly expressed.”
He went on: “it would have caused me such pain and regret had Mr. Darwin’s excess of generosity led him to make public my paper unaccompanied by his own much earlier and I doubt not much more complete views on the same subject and I must again thank you for the course you have adopted, which while strictly just to both parties, is so favourable to myself.”
And in Darwin’s response to Wallace, there was some relief. “Though I had absolutely nothing whatever to do in leading Lyell and Hooker to what they thought a fair course of action, yet I naturally could not but feel anxious to hear what your impression would be. I owe indirectly much to you and them for I almost think that Lyell would have proved right and I should never have completed my larger work, for I have found my abstract hard enough with my poor health...”
The Linnaen Society will celebrate the anniversary of the Darwin and Wallace papers with a special meeting on July 1 and further meetings later in the year. They will also award the Darwin-Wallace medal for the first time since the centenary of the meeting in 1958. But there’s no doubt that next year the celebrations will mostly be Darwin’s. 
Wallace considered the term 'survival of the fittest' less misleading than 'natural selection'
Bicentennial celebration of Darwin's birth in 2009
The year 2009 marks the bicentenntial of Darwin's birth, but it also marks the 150th anniversary of the publication of Darwin's book, On the Origin of Species by Means of Natural Selection...., announcing to the world the discovery of the evolutionary principal of natural selection. Beccaloni and Smith of the Natural History Museum in the UK note that the planned celebrations for the bicentennial birth celebration downplays the 'natural selection' announcement, and in particular the role of Alfred Russel Wallace as independent co-discoverer of the principle: "....to our knowledge, very little is being planned to celebrate the 150th anniversary of the discovery of natural selection...This lack of interest in the 2008 anniversary is indicative of how Wallace's achievements have been overshadowed by Darwin's since Wallace's death in 1913, a process certainly not helped by the Darwin 'industry' of recent decades....Isn't it perhaps time for the current darwinocentric view of the history of biology to be revised?" Kutschera explains but does not excuse Wallace's overshadowing on three grounds: (1) that Darwin's publication of On the Origin.... presented a much more detailed explication than Wallace's short paper read at the Linnean Society, and became a best seller; (2) that Wallace had always acknowledged Darwin's priority in discovering the principle, and even coined the term 'darwinism' to refer to it; (3) that Wallace lost credibility among scientists for his embracing of spiritualism and a variety of pseudosciences. Kutschera offers the following 'solution:
- What can we do to rehabilitate Wallace and to acknowledge his important contributions to evolutionary biology? The ‘Darwin–Wallace principle of natural selection’ could be substituted for the old-fashioned ‘darwinism’, which smacks more of a political ideology than a modern scientific theory. This simple change in terminology might restore balance to the Darwin-dominated view of the history of the life sciences.
References and Notes Cited in Text
- See for example: Wallace A. (1863) Varieties of Man in the Malay Archipelago. The Anthropological review, Volume 1, pp. 441.-444. | Google eBook Free.
- Wallace AR. (1905) My life: A record of events and opinions. London: Chapman and Hall. Volume 1. Full-Text in Image Format, from: The Complete Works of Charles Darwin Online, The Freeman Bibliographical Database
- Kutschera U. (2003) A Comparative Analysis of the Darwin-Wallace Papers and the Development of the Concept of Natural Selection. Theory Biosci. 22: 343-359.
- The author compares the papers of Darwin and Wallace read before the Linnaean Society in London in 1858.
- "It is shown that the contributions of A.R. Wallace, who died 90 years ago, are more significant than usually acknowledged. I conclude that natural selection's lesser known co-discoverer should be regarded as one of the most important pioneers of evolutionary biology, whose original contributions are underestimate by most contemporary scientists."
- Slotten RA. (2004) The 'Heretic in Darwin's Court: The Life of Alfred Russel Wallace. Columbia University Press. ISBN 0231130104. Numerous excerpts here.
- Ross A. Slotten, M.D., is a family practitioner in private practice in Chicago. He is a Wallace enthusiast and has retraced a number of Wallace's travels in Indonesia.
- From the publisher: "After examining his early years, the biography turns to Wallace’s twelve years of often harrowing travels in the western and eastern tropics, which place him in the pantheon of the greatest explorer-naturalists of the nineteenth century. Tracing step-by-step his discovery of natural selection—a piece of scientific detective work as revolutionary in its implications as the discovery of the structure of DNA—the book then follows the remaining fifty years of Wallace’s eccentric and entertaining life. In addition to his divergence from Darwin on two fundamental issues—sexual selection and the origin of the human mind—he pursued topics that most scientific figures of his day conspicuously avoided, including spiritualism, phrenology, mesmerism, environmentalism, and life on Mars."
- Benton zt. (2008) Wallaces Dilemmas: The Laws of Nature and the Human Spirit. Chapter 20. In: Smith CH, Beccaloni G. (editors) (2008) Natural Selection and Beyond: The Intellectual Legacy of Alfred Russel Wallace. Oxford: Oxford University Press. ISBN 9780199239160. | Google Books preview.
- While both agreed that humans had emerged from some primate ancestor in the remote past, Wallace became convinced that some "superior intelligence" had played a part in the development of the "higher" moral and mental faculties that raised humans far above other animal species. By contrast, Darwin remained committed to a thoroughly materialistic understanding of human evolution and distinctive character.
- Bowler P. (2008) Forward. In: Smith CH, Beccaloni G. (editors) (2008) Natural Selection and Beyond: The Intellectual Legacy of Alfred Russel Wallace. Oxford: Oxford University Press. ISBN 9780199239160. | Google Books preview.
- Wallace AR. Malay Archipelago Volume 1 The World Wide School. August 2001. Seattle, Washington.
- First paragraph chapter 1: From a look at a globe or a map of the Eastern hemisphere, we shall perceive between Asia and Australia a number of large and small islands [~20,000] forming a connected group distinct from those great masses of land, and having little connection with either of them. Situated upon the Equator, and bathed by the tepid water of the great tropical oceans, this region enjoys a climate more uniformly hot and moist than almost any other part of the globe, and teems with natural productions which are elsewhere unknown. The richest of fruits and the most precious of spices are Indigenous here. It produces the giant flowers of the Rafflesia, the great green-winged Ornithoptera (princes among the butterfly tribes), the man-like Orangutan, and the gorgeous Birds of Paradise. It is inhabited by a peculiar and interesting race of mankind--the Malay, found nowhere beyond the limits of this insular tract, which has hence been named the Malay Archipelago.
- Malay Archipelago Encyclopædia Britannica. 2008. Encyclopædia Britannica Online. 22 Dec. 2008.
- Wallace AR. (1889) [http://www.archive.org/stream/narrativeoftrave00wall : A Narrative of Travels on the Amazon and Rio Negro, With an Account of the Native Tribes, and Observations on the Climate, Geology, and Natural History of the Amazon Valley.] Second Edition [moderately revised; deletes Appendix on Indian languages]. Minerva Library of Famous Books, Vol. 8: Ward, Lock & Co., London, New York, & Melbourne, Nov. 1889.
- Dawkins R. (2001) The Reading of the Darwin-Wallace papers commemorated – in the Royal Academy of Arts. A speech given by Richard Dawkins FRS on 26th November 2001, unveiling the plaque in the Royal Academy commemorating the reading of the Darwin-Wallace papers at the Linnean Society on July 1st 1858 (see The Linnean 17(4) October 2001). THE LINNEAN: Newsletter and Proceedings of THE LINNEAN SOCIETY OF LONDON, Burlington House, Piccadilly, London W1J 0BF, VOLUME 18 • NUMBER 4 • OCTOBER 2002.
- See map of Usk and surroundings.
- Note: Wallace had come to accept phrenology as a valid science in his early 20s.
- The 1858 Darwin-Wallace paper.
- On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection. By CHARLES DARWIN, Esq., F.R.S., F.L.S., & F.G.S., and ALFRED WALLACE, Esq. Communicated by Sir CHARLES LYELL, F.R.S., F.L.S., and J. D. HOOKER, Esq., M.D., V.P.R.S., F.L.S, &c. [Read July 1st, 1858.]
- Wallace AR. (1889) Darwinism: An Exposition of the theory of Natural Selection, with Some of Its Applications. London: MacMillan. 494 p. | Google Book full-view & downloadable as PDF or EPUB.
- LETTERS. C. Darwin to C. Lyell. Down, 18th [June 1858.”]
- MY DEAR LYELL,—Some year or so ago you recommended me to read a paper by Wallace in the 'Annals,' [Annals and Mag. of Nat. Hist., 1855] which had interested you, and, as I was writing to him, I knew this would please him much, so I told him. He has to-day sent me the enclosed, and asked me to forward it to you. It seems to me well worth reading. Your words have come true with a vengeance—that I should be forestalled. You said this, when I explained to you here very briefly my views of 'Natural Selection' depending on the struggle for existence. I never saw a more striking coincidence; if Wallace had my MS. sketch written out in 1842, he could not have made a better short abstract! Even his terms now stand as heads of my chapters. Please return me the MS., which he does not say he wishes me to publish, but I shall, of course, at once write and offer to send to any journal. So all my originality, whatever it may amount to, will be smashed, though my book, if it will ever have any value, will not be deteriorated; as all the labour consists in the application of the theory….I hope you will approve of Wallace's sketch, that I may tell him what you say….My dear Lyell, yours most truly,….C. DARWIN.
- Wallace AR. (1895) The Method of Organic Evolution. Fornightly Review, March.”
- “The essential character of a species in biology is, that it is a group of living organisms, separated from all other such groups by a set of distinctive characters, having relations to the environment not identical with those of any other group of organisms, and having the power of continuously reproducing its like.”
- Kutschera calls attention to its similarity to the modern species concept later articulated by [Ernst May]]. In 1895, March, Wallace had less than a year to go to reach 80 years.
- Williams N. (2008) Evolution's forgotten anniversary. Current Biology 18:R316-R317.
- Bedall BG. (1988) Wallace's Annotated Copy of Darwin's Origin of Species. Journal of the History of Biology, 21:265-289.luwer Academic
- Beccaloni GW, Smith VS. (2008) Celebrations for Darwin downplay Wallace's role. Nature 451:1058 PMID 18305520
- Entomology Department, The Natural History Museum, UK
- Kutschera U. (2008) Darwin-Wallace principle of natural selection. Nature 453:27 PMID 18451834
- Institute of Biology, University of Kassel, Kassel, Germany
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