Monument to Wallace unveiled in Indonesia

March 5, 2019 • 11:15 am

by Greg Mayer

George Beccaloni, fellow Wallaceophile, has sent word that a monument to Alfred Russel Wallace has been erected on the Indonesian island of Sulawesi.

Wallace Monument, Tangkoko Nature Reserve, Sulawesi. Photo by Simon Purser.

As described at the Alfred Russel Wallace Website of the Wallace Memorial Fund by George and Simon Purser, the monument is a full bust, greater than life size (about 5-6 feet tall), on a nearly 9 foot tall plinth. It’s in the Tangkoko Nature Reserve, near Batu Putih, in the northeastern part of Sulawesi, an area Wallace visited during his travels in the East Indies. Wallace described the area in The Malay Archipelago as a particularly wild spot, with anoa (dwarf buffalo) and babirusa (an endemic pig) common. Those ungulates are gone from the area today, but it remains a popular spot for birding and seeing the Celebes black “ape” (actually a monkey; “Celebes” is an earlier, Portuguese, spelling of the Indonesian name of the island).

Bill Wallace, Alfred’s great grandson, prepared a video greeting shown to the assembled dignitaries at the monument’s inauguration.

Here at WEIT we’ve often commented on the great British naturalist, and readers will recall our several Wallace Year (2013) commemorations.

Wallace bust at Tangkoko.

Teaching Evolution: Alfred Russel Wallace: Geographical distribution

May 2, 2018 • 12:30 pm

by Greg Mayer

Our sixth installment is a paper by Alfred Russel Wallace. Written while he was still collecting in the Malay Archipelago, it is a foundational work in zoogeography, in which Wallace invokes a long history of evolutionary changes of organisms, and geographical changes of the land and water, to account for organisms’ current distributions and affinities. Readers may recall that 2013 was the centenary of Wallace’s death, and that we posted a series of commemorative posts on Wallace here at WEIT to celebrate his accomplishments during that year.  (Follow this link for many WEIT postings on Wallace.)

Alfred Russel Wallace (1823-1913) was co-discoverer, with Charles Darwin, of natural selection. A gentleman but from a family of lesser means than Darwin, he was largely self-taught. He first made a name for himself by conducting an expedition to the Amazon (1848-1852) with Henry Bates; unfortunately, most of his specimens were lost when his ship sank on the return to England. Setting out again on a natural history collecting expedition, he traveled in the Malay Archipelago from 1854-1862. It was at Ternate in 1858, that, during a bout of malaria, the concept of natural selection came to him. Wallace is widely acknowledged as the greatest figure in the history of zoogeography. A lifelong friend of Darwin, in later life he became a staunch public advocate of socialism and, much to the chagrin of his scientific colleagues, spiritualism. His books include The Malay Archipelago (1869), Contributions to the Theory of Natural Selection (1870, a collection of his papers, including the important ‘Sarawak’ and ‘Ternate’ papers), his monumental The Geographical Distribution of Animals (1876), Island Life (1880), and Darwinism (1889). Andrew Berry has edited a wide ranging anthology of Wallace’s writings, Infinite Tropics (2002).  All of Wallace’s published works are available at John van Wyhe’s superb Wallace Online.  A modern, scientific biography is Peter Raby’s Alfred Russel Wallace: A Life (2002).

Wallace, A.R. 1860. On the zoological geography of the Malay Archipelago. Journal of the Proceedings of the Linnean Society, Zoology 4:172-184.

Study Questions:
1. The comparison of which particular islands’ faunas helped Wallace epitomize the nature of the boundary between the Indian (= Oriental) and Australian regions? What are the geographic, climatic, and geological circumstances of these islands? What are their faunal differences and similarities?

2. What importance does Wallace place on the depth of the sea? Show how he uses it in accounting for the geographical distribution of animals.

3. What explanatory principles does Wallace invoke to explain the phenomena he discusses? What do these principles reveal about Wallace’s thinking at the time he wrote this paper?


An Okinawan thrush and the principles of zoogeography

March 10, 2016 • 3:15 pm

by Greg Mayer

My Okinawan correspondent sends the following photograph of an apparently window-killed bird.

Window-killed thrush, Okinawa, Japan, 8 March 2016.
Window-killed thrush, Okinawa, Japan, 8 March 2016.

I thought immediately, “a thrush”, noting the similarity in bill, body and leg shape to that of the familiar North American Robin (Turdus migratorius). I was also immediately reminded of the justly famous opening passage in Alfred Russel Wallace’s Island Life, in which, comparing the birds of Britain and Japan, he finds them remarkably similar:

WHEN an Englishman travels by the nearest sea-route from Great Britain to Northern Japan he passes by countries very unlike his own, both in aspect and natural productions. The sunny isles of the Mediterranean, the sands and date-palms of Egypt, the arid rocks of Aden, the cocoa groves of Ceylon, the tiger-haunted jungles of Malacca and Singapore, the fertile plains and volcanic peaks of Luzon, the forest-clad mountains of Formosa, and the bare hills of China, pass successively in review; till after a circuitous voyage of thirteen thousand miles he finds himself at Hakodadi in Japan. He is now separated from his starting-point by the whole width of Europe and Northern Asia, by an almost endless succession of plains and mountains, arid deserts or icy plateaux, yet when he visits the interior of the country he sees so many familiar natural objects that he can hardly help fancying he is close to his home. He finds the woods and fields tenanted by tits, hedge-sparrows, wrens, wagtails, larks, redbreasts, thrushes, buntings, and house-sparrows, some absolutely identical with our own feathered friends, others so closely resembling them that it requires a practised ornithologist to tell the difference. If he is fond of insects he notices many butterflies and a host of beetles which, though on close examination they are found to be distinct from ours, are yet of the same general aspect, and seem just what might be expected in any part of Europe. There are also of course many birds and insects which are quite new and peculiar, but these are by no means so numerous or conspicuous as to remove the general impression of a wonderful resemblance between the productions of such remote islands as Britain and Yesso.

(Perhaps inspired by Wallace, the Japanese ornithologist Masa Hachisuka once published a comparative list of the birds of Britain and Japan.) Wallace went on to contrast the remarkable similarities between the birds of these two distant archipelagos with the differences one finds when crossing the narrow strait between Bali and Lombok:

In the Malay Archipelago there are two islands, named Bali and Lombok, each about as large as Corsica, and separated by a strait only fifteen miles wide at its narrowest part. Yet these islands differ far more from each other in their birds and quadrupeds than do England and Japan. The birds of the one are extremely unlike those of the other, the difference being such as to strike even the most ordinary observer. Bali has red and green woodpeckers, barbets, weaver-birds, and black-and-white magpie-robins, none of which are found in Lombok, where, however, we find screaming cockatoos and friar-birds, and the strange mound-building megapodes, which are all equally unknown in Bali. Many of the kingfishers, crowshrikes, and other birds, though of the same general form, are of very distinct species; and though a considerable number of birds are the same in both islands the difference is none the less remarkable—as proving that mere distance is one of the least important of the causes which have determined the likeness or unlikeness in the animals of different countries.

Wallace, of course—in this and many other works—went on to explicate what the important causes of these disparities were, not the least of which are the evolutionary and geological histories of the organisms and land masses. (In the case of Bali and Lombok, the key factor has turned out to be that Bali is on the Asian continental shelf, and thus has been in frequent dry-land contact with the continental fauna, while Lombok is off the shelf, and has received its fauna over water by occasional means of transport.)

Like Wallace’s traveling Englishman, I too was struck by the great familiarity to me of this bird from the opposite side of the world. But while it was certainly a thrush, and almost certainly in the genus Turdus, I could not identify the species. I don’t have a Japanese or East Asian bird field guide, but checking some pictures on the internet, it seems most similar to T. pallidus, a winter visitor to Okinawa. Our deceased friend seems too white below, so I leave its species undetermined. Perhaps some reader will be able to identify it.

Window-killed thrush, Okinawa, Japan, 8 March 2016.
Window-killed thrush, Okinawa, Japan, 8 March 2016.

In addition to being a familiarly thrush-like bird, it was also, sadly, in a familiar posture: dead outside a glass door. Window-killed Swainson’s thrushes (Catharus ustulatus) are an all too familiar sight here in southeastern Wisconsin. My correspondent added about this bird, “Such a shame to see a dead bird, because they’re actually kind of rare to see. I blame the cats and Habu.” Habu are any of various pit vipers found in the Ryukyu Islands, which I thought were not common. I’ve queried my correspondent as to the relative abundance of cats and habu.

Hachisuka, M.U. 1925. A Comparative Hand List of the Birds of Japan and the British Isles. Cambridge University Press, Cambridge. (paperback published 2015)

Wallace, A.R. 1892. Island Life. 2nd ed. Macmillan, London. (at Wallace Online)

More good things by Wallace

November 23, 2013 • 11:46 am

by Greg Mayer

We’ve already posted some things to read by and about Alfred Russel Wallace in honor of Wallace Year, including a list by me and a recent list by fellow Wallace-ophile Andrew Berry. There’s another item that I can recommend to WEIT readers, which I had known about and forgotten to mention, but Matthew has kindly reminded me of it: the Journal of Zoology has published a “virtual issue” of a number of Wallace’s papers.

Dactlylopsila trivirgata, the striped possum of the Aru Islands.
Dactlylopsila trivirgata, the striped possum of the Aru Islands. The nominate subspecies is endemic to Aru; other subspecies occur in New Guinea and Queensland.

The issue consists of 10 articles, by Wallace or scientists working on his collections, originally published in the Proceedings of the Zoological Society of London (later renamed the Journal of Zoology). The papers are technical– species descriptions, faunal lists– rather than synthetic statements of Wallace’s views. But papers such as these are the building blocks out of which Wallace constructed his zoogeographical and evolutionary theories. The article on Wallace’s search for the bird of paradise, a delightful scientific travelogue in the style of The Malay Archipelago, is perhaps the most entertaining of the collection.

The picture above is from an account of the mammals of the Aru Islands, including descriptions of new forms, by the famous zoologist J.E. Gray,  based on Wallace’s collections. In this paper, Gray named and described the striped possum, not only erecting a new species for it, but a new genus as well. The Aru Islands * lie on the great Sahul Shelf which connects New Guinea and Australia, and it is thus not surprising that striped possums were later found in New Guinea and Queensland, as all these were connected by dry land during Quaternary glacial periods. The striped possum (a marsupial, of course) is thus a nice building block for the general conclusion that the fauna of the Aru Islands is of Australian affinity, and that former land connections are of great importance in understanding the distribution of animals, especially mammals.

There are many fine plates, like the one above, in these 10 articles. I’m not sure how long Wiley (the current printer for the Zoological Society of London) will maintain open access at its site, but the articles are all out of copyright, and most or all are freely available at the Biodiversity Heritage Library (direct link to the Proceedings here), and of course also at Wallace Online and The Alfred Russel Wallace Page.

* This link is to a nice paper comparing Wallace’s visit to Aru today.

Some Reading for Wallace Year

September 16, 2013 • 12:44 pm

by Greg Mayer

I should probably have posted something like this earlier, but here are a few recommended books about and by Wallace. It’s an idiosyncratic list, reflecting what was interesting and available to me, but might still be useful as a starting point. Wallace is of course mentioned in many books on the general history of evolution and Darwinism, but the following are works devoted primarily or exclusively to Wallace. I’ll start with a few biographies of Wallace, then a collection of essays, and finally some things written by Wallace himself.

The frontispiece of Island Life, 1880.
The frontispiece of Island Life, 1880.

Raby, P. 2001. Alfred Russel Wallace: A Life. Princeton University Press, Princeton, N.J. A well-received biography by a Victorianist interested in scientific travellers, covering the whole of Wallace’s life.

Shermer, M. 2001. In Darwin’s Shadow: The Life and Science of Alfred Russel Wallace: A Biographical Study on the Psychology of History. Oxford University Press, Oxford. Another biography, by an author probably more familiar to WEIT readers as the editor of Skeptic magazine and for his efforts in combating pseudoscience. Shermer’s academic credentials are in the history of science, and this book is based on his doctoral dissertation. Although Shermer might not appreciate the comment, I found the book refreshingly free of the sort of semi-quantitative psycho-history that the subtitle threatens.

Wyhe, J. van. 2013. Dispelling the Darkness: Voyage in the Malay Archipelago and the Discovery of Evolution by Wallace and Darwin. World Scientific, Singapore. I’m reading this now, having recently gotten my copy, and hope to say more later. Although briefly covering the whole of Wallace’s life, it concentrates on his time in the Malay Archipelago, which was the most scientifically creative part of his life. Van Wyhe is of course the editor of both Darwin Online and Wallace Online.

Smith, C.H. and G. Beccaloni, eds. 2008. Natural Selection and Beyond: The Intellectual Legacy of Alfred Russel Wallace. Oxford University Press, New York. This is a collection of essays edited by Charles Smith, editor of the essential Alfred Russel Wallace Page, and George Beccaloni, who has led the Natural History Museum‘s celebrations of Wallace Year. The essays, by scientists and historians, cover a broad range of historical and scientific issues, everything from a tour of Wallace’s many homes, to his studies of animal coloration, to his fight against vaccination.

For the works of Wallace himself, we can always view the online versions at Wallace Online and the Alfred Russel Wallace Page, or go to a good library, but a number of Wallace’s works are still in print. Here’s a sampling of some of my favorites.

Wallace, A. R. 2002. Infinite Tropics: an Alfred Russel Wallace Anthology. A. Berry, ed. Verso, London. Edited by Wallaceophile Andrew Berry, this is a collection of excerpts from throughout Wallace’s writings on a broad range of topics. If you are going to have only one book of Wallace’s writings, and you want to see what he thought about (almost) everything, this is the one.

The new issue of Island Life by University of Chicago Press, with commentary by Larry Heaney.
The new issue of Island Life by Univ. of Chicago Press, with commentary by Larry Heaney.

Wallace, A.R. 1880. Island Life. Macmillan, London.  Just reissued by the University of Chicago Press, with commentary by my friend and colleague Larry Heaney of the Field Museum. Larry, well known for his work on Philippine Island mammal faunas, provides an extensive introduction that explicates and puts Wallace’s work in modern context. Being very interested in islands, it was the first of Wallace’s major works that I obtained a copy of for myself (I got the 1892 second edition).

Wallace, Alfred R. 1870. Contributions to the Theory of Natural Selection. MacMillan, London. My second Wallace book, obtained in exchange for a six-pack of beer, this is a collection of some of Wallace’s most important papers, including both the “Sarawak paper” and the “Ternate paper“. It was reissued in 2009 by Cambridge University Press.

Wallace, A.R. 1869. The Malay Archipelago: the Land of the Orang-utan, and the Bird of Paradise. Macmillan, London. There are many reissues of this book concerning Wallace’s travel and discoveries in the East Indies. The Dover reprint was long available, but is now out of print; here’s a recent in print edition.

Wallace is just starting to have his letters and notebooks get the same detailed attention that Darwin’s have. Here’s a recent issue of his letters written during his eastern expedition.

Wyhe, J. van, and K. Rookmaaker, eds. 2013.  Alfred Russel Wallace: Letters from the Malay ArchipelagoOxford University Press, Oxford. This is either just out or will be out soon; I haven’t seen a copy yet.

And finally, one of my favorite individual papers by Wallace, which I give as an assigned reading to my evolutionary biology classes.

Wallace, A. R. 1860. On the zoological geography of the Malay Archipelago. Journal of the Proceedings of the Linnean Society: Zoology 4: 172-184.  pdf

NASA launches a frog, and experimental biogeograhy

September 13, 2013 • 9:07 am

by Greg Mayer

On Sept. 6, NASA launched the Lunar Atmosphere and Dust Environment Explorer (LADEE) towards the moon, where it will go into orbit to gather data on the thin lunar atmosphere. But along with the rocket, a frog, apparently resting on the rocket or launch pad, was taken spaceward, before being thrown free.

An unidentified frog is launched along with the LADEE rocket (NASA photo).
An unidentified frog is launched along with the LADEE spacecraft on Sept. 6, 2013 (NASA photo).

NASA’s dry caption is priceless:

A still camera on a sound trigger captured this intriguing photo of an airborne frog as NASA’s LADEE spacecraft lifts off from Pad 0B at Wallops Flight Facility in Virginia. The photo team confirms the frog is real and was captured in a single frame by one of the remote cameras used to photograph the launch. The condition of the frog, however, is uncertain.

The photo reminded me immediately of a famous biogeographic experiment performed by Thomas Barbour (1884-1946) and Philip Darlington (1904-1983), who differed over the importance of land bridges (favored by Barbour) versus overwater dispersal (favored by Darlington) in the distribution of animals on islands. The experiment and its results are handed down from one generation of graduate students to the next by a well-known oral tradition at the Museum of Comparative Zoology, but the only published account I know of is by Bob O’Hara (1988):

A how-possibly experiment performed by Philip Darlington and Thomas Barbour at the Museum of Comparative Zoology has become legendary. Darlington and Barbour were disputing the possibility of frogs being dispersed in the West Indies by hurricanes. Darlington, who believed such dispersal was possible, took a bucket of live frogs up to the roof of the Museum, and, with Barbour standing on the lawn below, proceeded to throw the frogs to the ground, one by one. As each one hit the ground, Barbour examined it and called up “That one’s dead,” “So’s that one,” and so on. But after a few minutes, much to Barbour’s disappointment, the frogs all revived and started to hop away. Darlington had thus shown that hurricane dispersal was possible, or at least had removed one of Barbour’s objections to it, namely that it would be too rough on the frogs.

To Bob’s account I would add that the MCZ is 5 stories tall, which gives you some idea how far the frogs fell in their journey to the courtyard below. Bob used the experiment to illustrate his notion of a “how possibly” experiment, which demonstrates the possibility, though not the actual occurrence, of a phenomenon.

I thought of the experiment because I wondered about the “uncertain” fate of the frog. The frog appears to be outside the plume of hot gas escaping form the rocket engine. If so, and if the clear air around it has not been super-heated, the frog could well survive the fall. Many tree frogs are adept at jumping long distances, bodies flattened and limbs spread, so that they reach a terminal velocity more dependent on aerial friction than gravity. The so-called “flying frogs” are ones that have gotten very good at this, usually with both morphological and behavioral specialiazations (see Wallace’s flying frog, an apt example for Wallace Year).

I’m not sure about the identity of the frog. My guess is that it’s a tree frog of some sort. [Note: I’d originally guessed it was a  Cuban tree frog (Osteopilus septentrionalis), a large, introduced species in Florida, but that’s before I realized the rocket was launched from a facility at Wallops Island, Virginia, on the Delmarva Peninsula, and not from NASA’s more usual Florida launchpads.]

h/t Christian Science Monitor


O’Hara, R.J. 1988. Homage to Clio, or, toward an historical philosophy for evolutionary biology. Systematic Zoology 37:142–155. pdf

Wallace, Galton, and Gladstone

September 9, 2013 • 9:43 am

by Greg Mayer

What do these three have in common, besides being prominent Victorian Englishmen? The, to me, surprising answer is: fingerprinting! Faithful and informative reader Dom has sent the following picture from the Galton Collection of the special collections at University College London.

Gladstone's (left) and Wallace's fingerprints. Photo by Dom.
Gladstone’s (left) and Wallace’s fingerprints. Photo by Dom.

Here’s a closeup of Wallace’s fingerprints, with Wallace’s signature below. I can’t quite make out what’s below his signature; I think it is, in part, the date.

Wallace's fingerprints, taken May 28, 1891. Photo by Dom.
Wallace’s signature and fingerprints, taken May 28, 1891. Photo by Dom.

Francis Galton was Darwin’s cousin, and perhaps is best remembered for developing the techniques of regression and correlation in his failed attempt to create a statistical theory of genetics in his Law of Ancestral Heredity. The law, unfortunately for Galton, was wrong. There was a long debate between Galton’s statistical school (biometricians) and Mendelians over the nature of inheritance. R.A. Fisher, in 1918, synthesized the two views, showing that the statistical resemblances among relatives studied by the biometricians are exactly what you would expect if the underlying genetic factors were inherited in a Mendelian fashion, thus laying the basis for modern quantitative genetics.

Galton, who was a bit of a polymath, also popularized fingerprints as a means of individual identification, collecting a large number of them and studying their forms and variations; hence, he collected Wallace’s and Gladstone’s. Fingerprints do seem to be individually unique, but because the systems of comparing prints rely upon a scoring of similarity rather than total identity, mistakes can be made, a recent infamous case being the American lawyer from Oregon imprisoned (briefly) for carrying out the 2004 Madrid train bombing. (The mistake was made by the FBI in the US; Spanish police correctly called the fingerprints as not matching.)

William Ewart Gladstone was three times Prime Minister, and his long, unfriendly rivalry with the two-time Tory Prime Minister Benjamin Disraeli  was  one of the most prominent features of Victorian Britain. Gladstone once wrote a book arguing that it was the duty of the state to determine what the true religion was, and to promote that religion to the exclusion of others. (The true religion, of course, turned out to be Anglicanism.) He later changed his  mind, at least a bit, and supported a bill to redress a bit of the imbalance in state support for Anglican vs Catholic churches in Ireland. But because he had publicly declared his exclusive support for Anglicanism in his book, he resigned rather than vote for the measure he supported!

Gladstone supported the right of atheists to sit in Parliament (MPs were required at the time to take a Christian oath, though some allowances had been made for Jews and Quakers), and attempted to seat the famous Victorian atheist Charles Bradlaugh after the latter’s election in 1880. Gladstone’s Parliamentary maneuverings failed, and Bradlaugh was actually taken from the floor of the house to jail! Despite not being properly seated, Bradlaugh kept getting re-elected, and eventually was sort of seated, and secured the passage of an affirmation bill, allowing MPs to affirm their loyalty, rather than swear on the Christian God, in 1888.

Guest post: Darwin and Wallace at Burlington House

August 20, 2013 • 4:43 am

In honor of Wallace Year, Greg Mayer is doing a series of posts on The Man Who Came Second. This essay gives Greg’s take on the rivalry between Darwin and Wallace about the discovery of natural selection, and how it was resolved.


Darwin and Wallace at Burlington House

by Greg Mayer

The theory of evolution by natural selection, co-discovered by Charles Darwin and Alfred Russel Wallace, was announced to the world at a meeting of the Linnean Society held at Burlington House in Piccadilly on July 1,1858. Neither Darwin, who was at Down House in Kent, nor Wallace, who was collecting in the Malay Archipelago, were present.

Seven weeks later, and 155 years ago today, the theory was published in the Society’s Journal—on 20 August 1858 (Darwin and Wallace, 1858).  Darwin provided a much fuller account of the theory the following year in On the Origin of Species (Darwin, 1859), and went on to write several more books, each of which may be considered an elaboration or application of the theory. Wallace remained in the East Indies until 1862. After returning to England, he too wrote several books, the best known being his account of his East Indian expedition (Wallace, 1869), his applications of evolutionary reasoning to zoogeography (Wallace, 1876, 1880), and a general exposition of evolution (Wallace, 1889).

Burlington House today (from the Linnean Society).
Burlington House today (from the Linnean Society).

Although the theory at its announcement was attributed to both men, it has come to be associated primarily with Darwin. Indeed, even Wallace entitled one of his most important books Darwinism (1889), and always considered Darwin to be at least primus inter pares. Some, however, have thought that Darwin’s lion’s share of the credit is undeserved, and that Wallace has been wronged, both by Darwin and by history (Brackman, 1980; Brooks,1983; Quammen, 1996; Davies, 2008).

The accusations against Darwin are that he ‘stole’ one or more ideas from Wallace, and that the circumstances of the reading and publication of the Linnean Society papers were somehow unethical. Although ostensibly arguing on Wallace’s behalf, these authors must dismiss Wallace’s own accounts (e.g. 1870, 1889, 1905, 1908) of the contributions made by Darwin and himself, and paint Wallace as a victim. But, as his biographer Raby (2001:291) says, “Wallace was not a victim, and he did not see himself as a victim”; to do so “diminishes both Darwin and Wallace.”

I argue here, in agreement with Raby and others, that these accusations are baseless, and that a fair reading of the historical evidence shows that the high and friendly regard (Kottler, 1985; Raby, 2001; Shermer, 2002) in which the two men held each other throughout their lives was well deserved on both their parts.

It is helpful to begin by recounting some of the history of both Darwin and Wallace, for it sets the context for later events. The following account draws on standard historical works, especially Kottler (1985), Browne (1995), Ruse (1999), Raby (2001), Shermer (2002), Bowler (2003) and Young (2007).

When Darwin returned from the Beagle voyage in late 1836, he was not yet an evolutionist, but by mid-1837, when he began his first notebook on transmutation, he was. By late 1838, after considering a number of possibilities, he hit upon natural selection as the mechanism of transmutation, and for the rest of his life he was to consider this the chief (though not exclusive) mechanism of evolutionary change. In 1842 he wrote a 35-page outline of his views which has come to be known as the Sketch. Darwin elaborated this into a 230-page Essay in 1844 (both were eventually published in 1909). At this time he first revealed his theory of natural selection, showing the Essay to the botanist J.D. Hooker. The theory in the Sketch and the Essay is the same as that given in the Origin. As Wallace had not yet published on—or even thought very much about—the subject, Wallace had no influence on Darwin’s formulation of natural selection.

Wallace’s evolutionary history begins a few years after Darwin’s return to England. He became a transmutationist in 1845 after reading Chambers’ (1844) Vestiges of the Natural History of Creation. From 1848 to 1852, Wallace conducted fieldwork in the Amazon basin with Henry Bates, making investigations and collections in all departments of natural history. Setting out for the East Indies in 1854, he once again benefited from having already accepted transmutation, so that he was ready to interpret the phenomena he observed in that context. Wallace, like Darwin, needed a mechanism of transmutation, but unlike Darwin he did not delay in publishing his incomplete views. In 1855 he wrote and published in the Annals and Magazine of Natural History what is known as his Sarawak paper. In it he stated that new species come into being near in time and space to allied species, but without supplying a mechanism for their origin.

The paper received little public attention. Darwin thought it just another vaguely transmutationist work. The geologist Charles Lyell, however, thought it very important, and said so to Darwin. In 1856, Darwin explained his theory to Lyell, and Lyell pressed him to begin his “big book on species”. And so, Darwin did.

It was while working on this “big book” (eventually published in 1975 as Natural Selection) in June of 1858 that Darwin received from Wallace his famous “Ternate paper”, in which Wallace formulated his theory of evolution by natural selection. Darwin could not, of course, have stolen the idea of natural selection itself from Wallace, for, as we have seen, it had been demonstrably laid out by Darwin almost two decades earlier. The idea Darwin’s detractors most suspect of having been stolen from Wallace is the “principle of divergence”, the chief import of which is that ecological specialization can drive divergence, and thus lead to a multiplication of species in the same locality. Kohn (1981, 1985) and Kottler (1985) have analyzed this concept in some detail. As Kohn notes, Darwin included in this principle several ideas (the branching nature of phylogeny, sympatric speciation, interspecific interactions, ecological specialization) which, while familiar enough individually, do not to us today seem to form an ineluctable whole.

Both Kohn and Kottler consider Darwin’s and Wallace’s concepts of  divergence significantly different, so that Darwin could not have gotten his ideas from Wallace. Kottler argues that in his Ternate paper, Wallace considered only linear or phyletic divergence (i.e., anagenesis), while Darwin’s principle embraced not only this, but branching divergence as well (i.e., cladogenesis, the divergence of two or more species descended from a single common ancestor). Kohn concludes that Darwin had formulated his principle of divergence by January 1855; Darwin (1958), in his autobiography, implies he had done so by early 1856; according to Kottler, Darwin had formulated his principle by 1857 at the very latest. By any of these datings, Darwin could not have been influenced by the Ternate paper of 1858.

If we look at readily available archival materials, we can see that most of the parts of Darwin’s concept were already present in his writings well before Wallace published anything. In his ‘B’ notebook, written in the late 1830s, Darwin includes his first sketches of the branching tree (or coral) of life (Darwin, 1987:177, 180). In the ‘D’ notebook, in September 1838, he uses the metaphor of the “wedge”, with every species trying to fill gaps in the economy of nature (Darwin, 1987:375-6). And, in a note dated January 1855, he writes of “diversity of structures supporting more life” (i.e. ecological specialization leading to greater diversity) (Kohn, 1985:256). I thus do not see that Wallace, in either the Sarawak or Ternate papers, supplied anything wanting in Darwin’s conceptual armamentarium. It takes nothing from the perspicacity of Wallace, or the import of his views for the world at large, to conclude, as do both Kohn and Kottler, that for Darwin, Wallace’s Ternate paper was an “intellectual non-event”.

When Wallace sent his paper, he asked Darwin to pass the paper on to Lyell. Darwin was much distressed by the paper, as it contained, he thought, his own views in miniature, even though more sober reflection revealed a number of differences in their formulations of the concept (Kottler, 1985; Shermer, 2003). Darwin passed the paper on to Lyell, not wanting to do anything unfair to Wallace, but at the same time not wanting his own 20 years’ work to go unrecognized.

Darwin was much distracted at this time by an outbreak of disease in his household, in which several fell ill, and his son Charles Waring died (his funeral was on July 1, the day the papers were read at Burlington House). Lyell and Hooker arranged for a reading of Wallace’s paper, along with an excerpt from Darwin’s Essay and a letter from Darwin to Asa Gray written in 1857, at the next meeting of the Linnean Society, which was on July 1. In presenting them, Lyell and Hooker arranged them, delicately perhaps, in chronological order (Burkhardt and Smith, 1991:107-128).

Darwin’s detractors argue that Darwin stole the principle of divergence when he received Wallace’s Ternate paper, that he lied about exactly when the manuscript and other of Wallace’s correspondence arrived, and that he destroyed letters to cover up his actions.

The first of these claims is, as we have already seen, belied by the fact that Darwin had by this time already formulated his principle of divergence. The second is based on the unproven assumption that Wallace’s letter was posted on March 9 (which would get it to London on about June 3). But as Shermer (2003:133) suggested, and van Wyhe and Rookmaaker (2012) have demonstrated, had it been posted on the April mail steamer, it would have arrived at Down House on June 18, precisely when Darwin said it did (Burkhardt and Smith, 1991:107-108). And, given that Wallace’s letter referred to a matter which he did not learn of till the arrival of the March 9 mail steamer, it is more likely that his manuscript and letter were posted on the April mail steamer ( van Wyhe and Rookmaaker, 2012). The third is based on  unfamiliarity with the circumstances under which Darwin’s correspondence was saved and stored: Darwin used to routinely cut up his correspondence, saving relevant portions in topical folders, while discarding the rest, especially before 1862, and significant parts of what he did save were later lost to water damage (Kohn, 1981).

Finally, even if Darwin did not steal anything from Wallace, or lie about it, was it not unsavory to have Darwin’s excerpts published along with Wallace’s paper? Again, I think not. At the time of the arrival of Wallace’s paper, Darwin was well along writing Natural Selection (he suspended work on it, writing over the next year the ‘abstract’ that became the Origin.) Wallace did not ask that Darwin publish his paper, but that he should show it to Lyell. Darwin, had he wanted to be unfair to Wallace, could easily have read it, sent it on to Lyell, gotten it back, and then returned it to Wallace, with the advice that it was indeed worth publishing, and that if Wallace would revise and return it, he (Darwin) would submit it forthwith for publication. Given the delays involved in correspondence with the East Indies, it might have taken six months for such an exchange to occur (Raby, 2001), giving Darwin ample time to publish his views before Wallace. And if Darwin were so malicious, he could simply have not showed the letter and manuscript to anyone (Shermer, 2002: 132).

Lyell and Hooker’s actions in fact advanced the publication of Wallace’s views further than Wallace could have hoped. On the other hand, not to publish Darwin’s views at the same time would have been a grave injustice to Darwin, since Lyell and Hooker knew that Darwin had been working on the species problem for many years, and had a much more substantial, though incomplete, manuscript in hand. Had Wallace been published alone, and received sole credit for natural selection, it would be regarded today as a much more curious and unjust turn of events than what did transpire.

Simultaneous publication was a “win-win” situation for Darwin and Wallace (1). Darwin established that he in fact had thought of natural selection first, and also received a strong stimulus to complete a fuller presentation of his views. Wallace established that his discovery of natural selection was, though later, entirely independent of Darwin’s. The circumstances allowed Wallace to later rightly insist that he not be classed with those forerunners, such as W.C. Wells and Patrick Matthew, who stated the principle of natural selection, but “failed to see its wide and immensely important applications” (1870:iv): Wallace did see its wide and immensely important applications.

Simultaneous publication gave Wallace the nihil obstat of Darwin, Lyell and Hooker, and thus a guarantee that his paper would be read and taken seriously, and not be overlooked, as he thought his Sarawak paper had been. Indeed, over and over again, Wallace expresses his satisfaction and, indeed happiness, over the arrangements made by Hooker and Lyell (Shermer, 2003; van Wyhe, 2013). Wallace wrote home that their action “insures me the acquaintance of these eminent men on my return home” (Wallace, 1905, I:365). Later, Wallace (1908:193) wrote, “I not only approved, but felt that they had given me more honour and credit than I deserved.” After learning what had been done, Wallace wrote to Hooker (6 October 1858: Burkhardt and Smith, 1991:166):

Allow me in the first place sincerely to thank yourself & Sir Charles Lyell for your kind offices on this occasion, & to assure you of the gratification afforded me both by the course you have pursued, & the favourable opinions of my essay which you have so kindly expressed. I cannot but consider myself a favoured party in this matter, because it has hitherto been too much the practice in cases of this sort to impute all the merit to the first discoverer of a new fact or a new theory, & little or none to any other party who may, quite independently, have arrived at the same result a few years or a few hours later.

Note that Wallace expresses satisfaction at being recognized at all, since the convention of the day was that credit went to the first discoverer rather than the first publisher of the discovery.

Van Wyhe (2013) summarizes:

In fact, none of Wallace’s statements indicate any dissatisfaction or disappointment. They contain only disarming qualifications that the work before the public had not been checked by him in proof. We could not expect a clearer or more unguarded indication of how Wallace received the news of the arrangement than the letter to his mother after learning the news. He told her that “Dr. Hooker and Sir C. Lyell… thought so highly of it that they immediately read it before the Linnean Society”. They thought so highly of it they had it immediately read! And that’s that. No matter how many times Wallace said how happy he was with the Linnean arrangement (and we have many instances), and how much he thought he benefited more than he deserved, this does not deter some Wallace fans from feeling aggrieved. Indeed, given how overwhelmingly advantageous the joint publication was for Wallace, it is hard to see how he could have regarded it as anything but positive and fortunate — which is how he described it in all of his later recollections. Wallace remarked in 1903, “My connection with Darwin and his great work has helped to secure for my own writings on the same questions a full recognition by the press and the public; while my share in the origination and establishment of the theory of Natural Selection has usually been exaggerated.” “It was really a singular piece of good luck that gave to me any share whatever in the discovery.” He felt he had received “ample recognition by Darwin himself of my independent discovery of ‘natural selection’”. And in his autobiography, Wallace stated that he “obtained full credit for its independent discovery”.

In the event, there was little reaction to the Linnean Society papers. The Linnean Society president, the herpetologist Thomas Bell, (in)famously remarked about the Society’s activities for 1858-1859 that, “The year which has passed has not, indeed, been marked by any of those striking discoveries which at once revolutionize, so to speak, the department of science on which they bear”. It was Darwin’s glowing mention of Wallace on page one of the Origin, in which Darwin stated that Wallace had arrived at “the same general conclusions” in his “excellent memoir”, that firmly established Wallace as the co-discoverer of natural selection and a leading figure in the new evolutionary biology.

Although the circumstances of independent discovery could have led to an ugly dispute about priority, they did not. Both Darwin and Wallace realized the value and nature of each other’s contributions, and both were content to share credit with the other. Although they later differed on a number of issues (Kohn, 1985; Kottler 1985; Shermer 2002), they remained friends and colleagues for life, standing figuratively side by side, fighting together the intellectual battle for their theory of evolution by natural selection against its many and powerful foes.


(1) In a striking coincidence, entirely independently of my usage of “win-win” in my 2002 essay, Shermer (2002), used the exact same words to describe his own view of the circumstances of publication, and elaborated on the notion of science as a “plus-sum game”. He writes (p. 148) of Darwin and Wallace of  “the special win-win nature of their relationship”; although I demurred at the suggestion, the editor of my essay proposed I entitle it “Darwin and Wallace: A “win-win” relationship”!

The preceding is adapted from a published paper (Mayer, 2002) which, in turn, was based on an earlier paper that was presented before the Malay Archipelago Reading Group of the Department of Zoology, University of Wisconsin, Madison. I am grateful to the members of that group, and especially Sher Hendrickson, for the opportunity to have done so, and for stimulating me to write the original essay. John Van Wyhe has kindly shared with me excerpts from his recent book and read and commented on this revision. Props to anyone who gets the Star Trek allusion in the title.


[Links are to Wallace Online (WO) and Darwin Online (DO).]

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