Alfred Russel Wallace

Alfred Russel Wallace at age 25 years.
Courtesty: The Alfred Russel Wallace Page

In the early 21st century, as well as in the previous century, many biologists have argued for a more informed and celebrated acknowledgement of the contributions to our understanding of evolution by the 19th century British naturalist and contemporary of Charles Darwin (b. February 12, 1809; d. April 19, 1882), Alfred Russel Wallace (b. January 8, 1823; d. November 7, 1913). 

Like Darwin, Wallace, 14 years Darwin's junior, possessed a passionate and inveterate desire to observe the natural world of plants and animals, both at home and in the unexplored wilds of the world. 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, Wallace came to the conclusion that nature selected for reproductive success those individuals of an interbreeding population with heritable traits enabling them to best cope with a changing environment threatening their ability to generate progeny — natural selection, or 'survival of the fittest'. Wallace developed the idea independently of Darwin, though not before Darwin had worked out the idea in great detail but before Darwin had published it.

In a speech by the eminent British evolutionary biologist, Richard Dawkins FRS, 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 papers describing natural selection at 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

Alfred Russel Wallace in 1902, at age 80, three years before publishing his autobiography. Courtesy: The Alfred Russel Wallace Page

We know a little of Wallace's early circumstances from his autobiography published in 1905, Wallace in his eighties.  Wallace came into the world of Usk, built near a river of that name, in Monmouthshire, Wales, in 1823, in a family of modest means, the eighth of nine children, all of whom he survived. In his 1905 autobiography, he explained in 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 out¬door 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.

Apparently Wallace came to accept phrenology as a valid science in his old age.

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.

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.