Charles Darwin - Alfred Russel Wallace
their Theory of Evolution
and Malthus Essay on Population
Charles Darwin was born on February 12th 1809 at
Shrewsbury, Shropshire, England. He was the fifth child of an highly reputable doctor named Robert
Waring Darwin and his wife Susannah; and the grandson of the
physician-scientist Erasmus Darwin, and of the pottery magnate
Josiah Wedgwood.
He was taught in accordance with a Greek language based
classics curriculum at Shrewsbury from 1818-1825. Although he had
not proved to have much academic aptitude at school in Shrewsbury
he then went to Edinburgh to study medicine but did not make
worthwhile progress - partly because he did not relish the suffering of patients or the sight of
blood resulting from medical procedures. In his autobiography he mentions
that;-
"soon after this period I became convinced from various
small circumstances that my Father would leave me property enough
to subsist on with some comfort ... my belief was sufficient to
check any strenuous effort to learn medicine".
Another attempt at securing a gentleman's education and career
was made, after his father had suggested the Church, by sending
him to Christ's College, Cambridge, in 1827, to study theology
with a view to becoming ordained as a clergyman.
During his Cambridge years he did not immerse himself in
Theological studies but rather fell in with a set who were keen
on fox-hunting and game shooting. He also loved to collect
plants, insects, and geological specimens, guided by his cousin
William Darwin Fox, an entomologist. He developed a particular
interest in collecting beetles, the rarer in species the better.
His autobiography quotes one particular beetle hunt in
detail:-
"I will give a proof of my zeal: one day on tearing off
some old bark, I saw two rare beetles and seized one in each
hand; then I saw a third and new kind, which I could not bear to
lose, so that I popped the one which I held in my right hand into
my mouth. Alas it ejected some intensely acrid fluid, which burnt
my tongue so that I was forced to spit the beetle out, which was
lost, as well as the third one".
His modest and untrained scientific inclinations were
encouraged by Alan Sedgewick, a geologist and also by a botany
professor, John Stevens Henslow, who was instrumental, despite
heavy paternal opposition, in securing a unpaid place for Darwin
as a naturalist on a long term scientific expedition that was to
be made by HMS Beagle. In fact he only won parental consent to
his joining the HMS Beagle after his uncle, Josiah Wedgewood II,
spoke on his behalf. The intended career in the church had, at no
time, been explicitly abandoned but his gaining the place on the
HMS Beagle meant that he took another path in life.
Alfred Russel Wallace (1823-1913) was born near Usk,
Monmouthshire (now part of Gwent), Wales as the eighth child of a family a family, where the father
of the family was employed as librarian in Hertford, an English county town not too far distant from London.
Unfortunately Mr. Wallace lost much of his remaining property through ill advised dealings in
1835 resulting in real hardship for the family - Alfred Russel Wallace, then barely into his teenage years, had
to cut short his formal education late in 1836.
Family contacts in the form of an older brother, William, owning a surveying business led to Wallace embarking
on a career as a surveyor where a growing interest in
Natural History could also be followed up, to some extent, between daily tasks.
It happened, however, that William Wallace's business fell on hard times causing Wallace to
lose his place in 1844. He was now successful in gaining a position as a teacher of Surveying in the Collegiate School
in Leicester where he had access to a library where there were several reliable books on Natural History.
In 1844
Wallace made the acquaintance of another young man seriously interested in Natural History named Henry Walter
Bates (1842-52), who although only nineteen years of age, was a well-recognised
proficient in the then fashionable pursuit of beetle-collecting and who had already been able to get some scholarly
work in Entomology printed in the learned journal, Zoologist.
Other formative developments in his life in these times included attendance at a demonstration of mesmerism -
Wallace found that he could himself reproduce the same effects as the mesmerist demonstated and, more seriously,
the death of his brother, William, in February 1845 which was followed by Wallace returning to surveying and his
brother, John, joining him
in the business. Wallace found his adminstrative responsibilities particularly arduous. After the failure of the
business Wallace worked as a surveyor in connection with a proposed railway in the Vale of Neath. He
also found time to give lectures on science and engineering at the Mechanics' Institute of Neath and to
act as a curator of the Neath
Philosophical and Literary Institute's museum.
His interest in Natural History continued and he entered into a regular correspondence
with his friend Henry Bates. During thes times Wallace seems to have read, and to have corresponded with
Henry Bates about, Charles Darwin's journal
on the Voyage of the Beagle, Charles Lyell's Principles of Geology which
offered to demonstrate how long-term change, in Geology in this instance, could be
effected through the operation of slow, long-term processes, and an anonomously published work Vestiges of the
Natural History of Creation, (later known to be by Robert Chambers), which was an early, popular, and
notably controversial effort at
arguing pursuasively against both Creationism
and Lamarckism as full explanations of the existence of the solar system, the earth, and the diversity of species.
The latter two of these works might be thought to have almost prepared Alfred Russel Wallace's mind for an
acceptance of evolutionism.
Wallace had read Charles Darwin's book about the Voyage of the Beagle and his admiration for the adventures
and the observations of natural phenomena that Darwin wrote about as having occured during the Beagle voyage
and also those related in
a book by William H.
Edwards entitled
A Voyage Up the River Amazon which came into Wallace's hands resulted in his
suggesting to his friend Bates that they set themselves up as professional collectors of Natural History specimens
to supply the needs of institutions and gentlemen
naturalists. The two young men, they were both in their early twenties, sailed for the mouth of the Amazon in April, 1848.
In South America Wallace and Bates worked independently of each other with Wallace travelling and collecting
samples in the Amazon basin for several years until, early 1852, ill health led him to decide to return home to England.
His
activities as a collector of Natural History
specimens, and his authorship of academic papers and of his two books that were fairly well received
brought him a little bit of notice in the then somewhat fashionable Natural History circles of society and,
during these times he became introduced to many interested persons including one Charles Darwin.
Wallace is considered to have been something of a convinced evolutionist but without seeing how
such evolution might be driven.
In September 1855 a paper entitled On the Law which has regulated the Introduction of New Species by ALFRED R. WALLACE, F.R.G.S.
(i.e. Fellow of the Royal Geographical Society) appeared in a scientifically inclined publication Known as the Annals and Magazine of Natural History.
In this paper Wallace sets out his "Law" which he claims to have discovered some ten years
previously and which he has since then been subject to testing. This possible Law being that:-
Every species has come into existence coincident both in space and time with a pre-existing closely allied species.
Shortly thereafter Wallace's paper continues:-
the order in which the several species came into existence, each one having had for its immediate antitype a closely related species existing at the time of its origin. It is evidently possible that two or three distinct species may have had a common antitype, and that each of these may again have become the antitypes from which other closely allied species were created.
This paper was read by Sir Charles Lyell who found its contents to suggest strongly that
Species were not fixed creations of God, but were in fact naturally mutable. As a friend of Charles Darwin,
who knew that Darwin had been
considering the Emergence of Species for a considerable time he subsequently urged Darwin to
make efforts to complete his work on related subjects to establish academic priority for his own ideas.
Darwin's work in this area had been on-going for a long time. He had returned from his five years of voyaging
and observation on the HMS Beagle
in 1836 with a newly critical attitude to Biblical explanations of Creation and much personal observation of
nature and of the operation of natural forces to consider.
As early as 1837 the direction of Darwin's mind can perhaps be illustrated by this famous
sketch from his Notebook B dating from 1837-8, (and deemed by editors of Darwin's papers to be concerned
with his thoughts about the Transmutation of Species), which shows an early attempt at a theoretical insight of how a genus of related species might
originate by divergence from a starting point (1):-
The text annotations read:-
I think
Case must be that one generation then should be as many living as now. To do this & to have many
species in same genus (as is) requires extinction.
Thus between A & B immense gap of relation. C & B the finest gradation, B & D rather greater
distinction. Thus genera would be formed. — bearing relation (page 36 ends - page 37 begins)
to ancient types with several extinct forms.
From Darwin's notebook B now stored in Cambridge University library
Late in life Charles Darwin was approached by a publisher who was keen to bring out Darwin's
Autobiography. A section of this work relates another key stage in his development of an inherently
persuasive hypothesis about a scenario where there would be a naturally explicable origin of species being his
reading, late in 1838, of an Essay by the Reverend
Thomas Malthus.
To use Charles Darwin's own words from his Autobiography.
I happened to read for amusement Malthus on 'Population', and being well prepared
to appreciate the struggle for existence which everywhere goes on from long-continued observation
of the habits of animals and plants, it at once struck me that under these circumstances favourable
variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this
would be the formation of a new species. Here, then, I had at last got a theory by which to work.
Darwin continued to develop a theory expaining the naturally arising development of new species but at the same time had begun
to think seriously that life as a scholarly bachelor
would be unappealing and decided to attempt to pay court to his
sincerely religious first cousin, Emma Wedgwood. By the summer of 1838 Emma agreed to marry Charles Darwin,
knowing him to hold skeptical views and even wrote to him soon after their engagement telling
him that she was sad that "our opinions on the most important subject should differ widely."
As wife to Charles Darwin Emma continued to hold strong
religious beliefs and to be distressed by the absence of God in her husband's theorising always quietly encouraging
him to see faith as a matter for "feeling, not reasoning".
Darwin had grown up in and, despite his own skepticism after returning from his voyages, continued to live in a society that generally accepted biblical
explanations of creation whereby the Earth and all of its unchanging, immutable, life forms were, as they were and
as they ever had been, as a result of Original Acts of Divine Creation.
Against this pervasive cultural background, in a confidential letter of 11 January
1844 to a fellow scientist named Joseph Hooker, Darwin wrote that he was engaged in a ‘very presumptuous work’
which had led to the conviction that ‘species are not (it is like confessing a murder) immutable’.
During 1844, Darwin, with Emma's editorial advice and participation, extended an initial thirty-five page abstract of his theory
written in pencil in 1842 by preparing a two hundred and thirty page-long overview
of his theory for publication in the event of his death. He also framed an accompanying letter to his wife asking her to
seek the aid of several of
his scientific friends to that end and setting aside a substantial sum to fund the project!
Thus even though he went to the trouble of gathering his thoughts so as to prepare a manuscript overview of his
theorising, Darwin actually preferred to keep his potentially most controversial
ideas a private matter because of
his reluctance to meet an expected adverse reaction from family, friends, and the wider public.
Despite the time and effort put into its preparation the manuscript overview was placed in storage in a securely sealed
packet that was labelled 'only to be opened in the event of my death' that Darwin placed in a cupboard under
the stairs of Darwin's home! It was to remain there for some fifteen years!
During these times Darwin continued to live in the Kent countryside and to thoroughly investigate how species might
change through converstions with pidgeon fanciers and farmers as well as conducting a large number of
scientific experiments. He kept up friendships with a wide range of persons and communicated widely
by letter with other parties interested in Natural History.
One such friendship was with Sir Charles Lyell and one particular debating point between them was whether
or not individual species were fixed in form or whether their forms were open to change.
As has already been mentioned in September 1855 a paper entitled On the Law which has regulated the Introduction
of New Species by ALFRED R. WALLACE, F.R.G.S. appeared in a scientifically inclined publication Known as
the Annals and Magazine of Natural History.
This paper was read by the famous geologist Sir Charles Lyell, a famous geologist and a personal friend
of long-standing to Charles Darwin. Lyell, against his own previous and strongly
held opinions, found its
contents to suggest strongly that species were not fixed creations of God, but were, in fact, naturally
mutable. In November 1855,
soon after reading Wallace's article, Lyell seems to have started keeping a "species notebook" in which
to record his own thoughts about a possible mutability in species.
Between 13-16 April 1856 Sir Charles Lyell and his wife paid a visit to the Darwins, at their home in the Kentish countryside. Lyell
made an entry in his diary on the 16 April headed ‘With Darwin: On the Formation of Species by Natural Selection’,
and cited, among other things, the example of pigeons.
Sir Charles Lyell heard word, about a week-end visit paid to the darwin's during the last week of April by
Joseph Dalton Hooker, Thomas Henry Huxley, and Thomas Vernon Wollaston, possibly from his scientific friends Hooker and Huxley
themselves. In a letter of 30 April 1856 to Charles James Fox Bunbury, Lyell stated: ‘When Huxley, Hooker, and Wollaston were
at Darwin's last week, they (all four of them) ran a tilt against species farther I believe than they are deliberately prepared to go.
Wollaston least unorthodox. In this letter Lyell also mentions something of his own discussions with Charles Darwin -
‘Darwin finds, among his fifteen varieties of the common pigeon, three good genera and about fifteen good species
according to the received mode of species and genus-making of the best ornithologists, and the bony skeleton varying with the rest!’
On 1 May 1856 Lyell wrote to Darwin about Natural history matters - this letter
included the phrase "hear that when you & Hooker & Huxley & Wollaston got together you made light of all species
& grew more & more unorthodox" - shortly thereafter Lyell wrote — "I wish you would publish some small fragment of your
data pigeons if you please & so out with the theory & let it take date—& be cited—& understood.
On 14 May 1856, Charles Darwin recorded in his journal that he ‘Began by Lyell's advice writing species sketch’.
Darwin did read Wallace's paper but later commented about Wallace's work - "it seems all
creation with him."
A letter of Darwin to Wallace from these times has survived:-
My dear Sir
I am much obliged for your letter of Oct. 10th. from Celebes received a few days ago: in a laborious
undertaking sympathy is a valuable & real encouragement. By your letter & even still more by your paper
in Annals, a year or more ago, I can plainly see that we have thought much alike & to a certain extent
have come to similar conclusions. In regard to the Paper in Annals, I agree to the truth of almost every
word of your paper; & I daresay that you will agree with me that it is very rare to find oneself
agreeing pretty closely with any theoretical paper; for it is lamentable how each man draws his own
different conclusions from the very same fact.—
This summer will make the 20th year (!) since I opened my first-note-book, on the question how & in what
way do species & varieties differ from each other.— I am now preparing my work for publication, but
I find the subject so very large, that though I have written many chapters, I do not suppose I shall
go to press for two years.—
From a letter by Charles Darwin to Alfred Russel Wallace dated May 1 1857
It was in 1858 whilst he was laid up with a malarial fever at Ternate, in the
Celebes Islands, that a possible solution to the method of evolution flashed into form in Wallace's mind.
The outcome being that this burst of inspiration together with his more longstanding ruminations
resulted in Alfred Russel Wallace independently framing a theory of the evolutionary origin of
species by natural selection.
At the time in question I was suffering from a sharp attack of intermittent fever, and every day during the cold and succeeding hot fits had to lie down for several hours, during which time I had nothing to do but to think over any subjects then particularly interesting me. One day something brought to my recollection Malthus's "Principles of Population", which I had read about twelve years before. I thought of his clear exposition of "the positive checks to increase" - disease, accidents, war, and famine - which keep down the population of savage races to so much lower an average than that of more civilized peoples. It then occurred to me that these causes or their equivalents are continually acting in the case of animals also; and as animals usually breed much more rapidly than does mankind, the destruction every year from these causes must be enormous in order to keep down the numbers of each species, since they evidently do not increase regularly from year to year, as otherwise the world would long ago have been densely crowded with those that breed most quickly. Vaguely thinking over the enormous and constant destruction which this implied, it occurred to me to ask the question, Why do some die and some live? And the answer was clearly, that on the whole the best fitted live. From the effects of disease the most healthy escaped; from enemies, the strongest, the swiftest, or the most cunning; from famine, the best hunters or those with the best digestion; and so on. Then it suddenly flashed upon me that this self-acting process would necessarily improve the race, because in every generation the inferior would inevitably be killed off and the superior would remain - that is, the fittest would survive. Then at once I seemed to see the whole effect of this, that when changes of land and sea, or of climate, or of food-supply, or of enemies occurred - and we know that such changes have always been taking place - and considering the amount of individual variation that my experience as a collector had shown me to exist, then it followed that all the changes necessary for the adaptation of the species to the changing conditions would be brought about; and as great changes in the environment are always slow, there would be ample time for the change to be effected by the survival of the best fitted in every generation. In this way every part of an animal's organization could be modified exactly as required, and in the very process of this modification the unmodified would die out, and thus the definite characters and the clear isolation of each new species would be explained. The more I thought over it the more I became convinced that I had at length found the long-sought-for law of nature that solved the problem of the origin of the species. For the next hour I thought over the deficiencies in the theories of Lamarck and of the author of the "Vestiges," and I saw that my new theory supplemented these views and obviated every important difficulty. I waited anxiously for the termination of my fit so that I might at once make notes for a paper on the subject. The same evening I did this pretty fully, and on the two succeeding evenings wrote it out carefully in order to send it to Darwin by the next post, which would leave in a day or two.
I wrote a letter to him in which I said I hoped the idea would be as new to him as it was to me, and that it would supply the missing factor to explain the origin of the species. I asked him if he thought it sufficiently important to show it to Sir Charles Lyell, who had thought so highly of my former paper.
From Alfred Russel Wallace : My Life, pp. 360-363.
And so it was that Wallace sent a twenty page long memoir about this
evolutionary theory to the influential expert
naturalist Charles Darwin, arrived in Darwin's hands in June 1858. In a covering letter Wallace asked that Darwin forward the memoir to a famous scientist, Sir Charles Lyell,
if Darwin thought the content merited his attention.
Darwin subsequently sent Wallace's manuscript to Lyell; with his own covering letter of
18th June 1858 that included the following sentences:-
My dear Lyell
Some year or so ago, you recommended me to read a paper by Wallace in the Annals, which had interested
you & 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 & asked me to forward it to you. It seems to me well worth reading. Your words have come
true with a vengeance that I shd. 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 manuscript 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 manuscript which he does not say he wishes me to publish; but I shall of course at once write
& 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.
Several days later Darwin again wrote to Sir Charles Lyell:-
As I had not intended to publish my sketch, can I do so honourably, because Wallace has sent me an outline of
his doctrine? I would far rather burn my whole book than that he or any other man should think that I
behaved in a paltry spirit. Do you not think that that his having sent me this
sketch ties my hands? I do not in least believe that that he originated his views from anything
which I wrote to him.
In the event, Darwin, in consultation with Sir
Charles Lyell and Sir Joseph Hooker, agreed that there should be
a public joint presentation of his own and Wallace's potentially
dramatically controversial views.
Neither Wallace nor Charles Darwin were present at the
historic meeting of the Linnaean Society in July 1858 when papers
attributable to each were brought to the attention of the wider
scientific public. Wallace's paper was presented under the title
"On the Tendency of Varieties to Depart Indefinitely from the
Original Type."
Wallace was several weeks letter-delivery time away in
the Moluccas and efforts were made by Darwin, Lyell and Hooker to keep him informed
of developments in London in relation to his sending his manuscript to Charles Darwin.
On October 6, 1858, Wallace wrote in a fairly magnanamous spirit to Hooker:-
My dear Sir
I beg leave to acknowledge the receipt of your letter of July last, sent me by Mr. Darwin, & informing me
of the steps you had taken with reference to a paper I had communicated to that gentleman. 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 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.
I also look upon it as a most fortunate circumstance that I had a short time ago commenced a correspondence
with Mr. Darwin on the subject of “Varieties,” since it has led to the earlier publication of a portion
of his researches & has secured to him a claim of priority which an independent publication either by
myself or some other party might have injuriously effected;—for it is evident that the time has now
arrived when these and similar views will be promulgated & must be fairly discussed.
It would have caused me much pain & regret had Mr. Darwin’s excess of generosity led him to make public my paper unaccompanied by his own much earlier & I doubt not much more complete views on the same subject, & I must again thank you for the course you have adopted, which while strictly just to both parties, is so favourable to myself.
Following on from Wallace's initial approach Darwin, besides
preparing a paper that was read to the Linnean Society, made
efforts to draw his notes together into a work intended for
publication. That work was prepared and published under the title
The Origin of Species in 1859.
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