Credit: Charles Darwin (1890) Journal of Researches Into the Natural History and Geology of the Countries Visited During the Voyage Round the World of H. M. S. 'Beagle' Under the Command of Captain Fitz Roy, New York City, NY: D. Appleton and Company. Freshwater and Marine Image Bank, University of Washington. Public domain.
In 1858 a paper that lists as its authors Charles Darwin and Alfred Wallace was published by the Linnean Society. The name of the paper? On the Tendency of Species to Form Varieties; and on the Perpetuation of Varieties and Species by Natural Means of Selection. Yes, that paper, the one in which the principles behind the theory of evolution and natural selection were introduced formally into the community of biologists.
Although Wallace's name appears on this paper, as author, that name has largely disappeared from public consciousness. When we speak of evolution, we think Darwinism. What is the story behind the association between the two scientists, an association so connected that each credited the other with doing ground-breaking work in the theory of natural selection?
Technically, the men were not co-authors. Both had written papers on the theory of natural selection and these two papers were published together on that historic day as a representation of a unified theory.
Megachile Pluto, also known a Wallace's Giant Bee, is the largest bee in the world (discovered so far). Wallace was a naturalist who had been trying to sort out an understanding of how species variation came to be. He had spent years in the Amazon collecting specimens. He continued his pursuit in the jungles of Malaysia. That's when he came upon the giant bee.
The story of Megachile Pluto is fascinating in itself, but along with that is the story of Alfred Russel Wallace, a name that is new to me, although Wallace is credited with independently arriving at the theory of natural selection--apart from Darwin. In 1858 Wallace sent Darwin a letter that described the natural selection theory. A stunned Darwin had been preparing to publish his own paper. Upon receiving Wallace's he decided that the only ethical way forward would be to include Wallace's findings along with his own.
Forms of Papilio ormenus Accepted name Papilio aegeus ormenus Guérin-Méneville
Credit: A. R. Wallace, 1865. As illustrated in his paper On the phenomena of variation and geographical distribution as illustrated by the Papilionidae of the Malayan region. Public domain
Wallace and Darwin were not competitors. Each acknowledged the contribution of the other in the development of the theory of natural selection. Not only did Darwin acknowledge Wallace's contribution, by including his work in the 1859 ground-breaking paper, but Wallace was a fierce defender of Darwin's theory. In 1889, when Wallace published a book describing his work on natural selection, the book was titled Darwinism.
Striped Possum, Illustration in the "List of species of Mammalia sent from the Aru Islands by Mr A.R. Wallace to the British Museum"
Credit: J. Wolf, 1858. From the Biodiversity Library. Public domain.
Why did Wallace fade into obscurity and Darwin rise to become one of the most recognized names in science? According to James T. Costa, professor of Biology at Western, Caroline University, an examination of Wallace’s writing showed that he not only paralleled Darwin's research, but had original, unique insights of his own.
Illustration from Wallace's Book, Darwinism, Page 225
Credit: Alfred Wallace. Scanned from his book, Darwinism. Text may be found here. Scanned by the Biodiversity Heritage Library. The script under the pictures reads: Scolopax megala (upper) S. stenura (lower). Public domain
Throughout his life Wallace expressed admiration for Darwin, and gratitude for Darwin's acknowledgment of his work. However, Wallace also stated that when his paper was published with Darwin's in 1859, it was done so without giving him the opportunity to edit. Wallace had never intended that paper to be published. It was sent merely as a letter of inquiry and as a matter of sharing research.
In time, it would turn out that Wallace had a view of natural selection that differed from Darwin's in one significant way: Wallace thought man was an exception. He felt that man's superior faculties could not be explained solely by natural selection. In 1869/1870 he published a paper entitled, The Limits of Natural Selection as Applied to Man. A quote from that paper"
I believe, proved that, as soon as the human intellect became developed above a certain low stage, man's body would cease to be materially affected by natural selection, because the development of his mental faculties would render important modifications of its form and structure unnecessary. ..I am now myself going to state objections, and to place limits, to the power of "natural selection....
Illustration of Chimpanzee (From Darwinism)
Credit: Alfred Wallace. From the chapter in his book on Application of Natural Selection to Man. 1889. Public domain.
Wallace compares brain sizes of apes and different types of humans. He compares brain sizes of prehistoric man to modern man. He compares hairy states, to hairless states. He addresses refinement of voice and softness of skin. After cataloguing all the ways in which modern, sophisticated man is superior, he asks why? How? If brain sizes are similar, then he surmises, it is not physical development (natural selection) which has guided man's advancement. It is something else. A quote:
The inference I would draw from this class of phenomena is, that a superior intelligence has guided the development of man in a definite direction, and for a special purpose, just as man guides the development of many animal and vegetable forms.
Portrait of Alfred Russel Wallace, 1913
Credit: Popular Science Library, Harvard University. Public domain
In his paper, and in other writing, Wallace asserts the action of an independent power on the evolution of man. By this, was Wallace, in essence, asserting the Christian doctrine of Intelligent Design? That is argued by people who understand Wallace and the concept of Intelligent Design better than I do. Certainly, Wallace was not a Christian. That's what most researchers claim. His theory is commonly described as 'Intelligent Evolution'.
Some researchers believe Wallace's views on man's special place in nature was influenced by the death of a son, Herbert. Wallace was convinced that the human spirit lived on after death and he became increasingly interested in spiritualism. His desire to pursue this belief as a matter of science dismayed some of his colleagues.
Spirit Photograph of Wallace (With His Mother)
Credit: Georgiana Houghton. Photo by Frederick Hudson in Chronicles Of The Photographs Of Spiritual Beings, E. W. Allen, 1882. Public domain
His active advocacy of spiritualism included his promotion of spirit photography as 'evidence' that life after death was provable. He states in his writing (as quoted on the Western Kentucky University website wku.edu) that spirit photography
...is that which furnishes, perhaps, the most unassailable demonstration it is possible to obtain of the objective reality of spiritual forms
Does Wallace's insistence on the exceptionalism of man, and spiritualism, explain his obscurity? While this advocacy might separate his perspective from that of most scientists today, in other ways Wallace was more 'modern' than Darwin.
Wallace was an egalitarian and believed that all humans had the potential for personal development. Darwin did not believe this. Wallace's assertion of 'intelligent evolution' would likely not meet with favor in much of the science community. Still, considering the contributions he made to understanding the basic principle of natural selection, one has to believe (I believe) that his historical obscurity is undeserved. Wallace was a trail blazer who made an astounding contribution to the advancement of science.
1LIL: LMAC Image Gallery, @muelli: Shells
Credit: @muelli on LIL. Public domain