To be sure, the contradictions between evolution and the Bible have been
addressed again and again. In fact, the critical issues were successfully
resolved long before Darwin published his views on natural selection in 1859.
What has not been repaired is the breach that opened up between science and
religion. The struggle for existence bears on Natural Selection. Geoffroy
Saint-Hilaire's ('Hist. Nat. Générale,' tom. ii. p. 405, 1859) excellent
history of opinion on this subject. In this work a full account is given of
Buffon's conclusions on the same subject. It is curious how largely my
grandfather, Dr Erasmus Darwin, anticipated the views and erroneous grounds of
opinion of Lamarck in his 'Zoonomia' (vol. i. pp. 500-510), published in 1794.
According to Isid. Geoffroy there is no doubt that Goethe was an extreme
partisan of similar views, as shown in the Introduction to a work written in
1794 and 1795, but not published till long afterwards: he has pointedly
remarked ('Goethe als Naturforscher,' von Dr Karl Medinge s. 34) that the
future question for naturalists will be how, for instance, cattle got their
horns, and not for what they are used. It is rather a singular instance of the
manner in which similar views arise at about the same time, that Goethe in
Germany, Dr Darwin in England, and Geoffroy Saint-Hilaire (as we shall
immediately see) in France; came to the same conclusion on the origin of
species, in the years 1794-5.
Geoffroy Saint-Hilaire, as is stated in his 'Life,' written by his son,
suspected, as early as 1795, that what we call species are various
degenerations of the same type. It was not until 1828 that he published his
conviction that the same forms have not been perpetuated since the origin of
all things. Geoffroy seems to have relied chiefly on the conditions of life, or
the 'monde ambiant' as the cause of change. He was cautious in drawing
conclusions, and did not believe that existing species are now undergoing
modification; and, as his son adds, "C'est donc un problème à réserver
entièrement à l'avenir, supposé meme que l'avenir doive avoir prise sur lui.'
In 1813, Dr W. C. Wells read before the Royal Society 'An Account of a White
female, part of whose skin resembled that of a Negro'; but his paper was not published
until his famous 'Two Essays upon Dew and Single Vision' appeared in 1818. In
this paper he distinctly recognises the principle of natural selection, and
this is the first recognition which has been indicated; but he applies it only
to the races of man, and to certain characters alone. After remarking that
negroes and mulattoes enjoy an immunity from certain tropical diseases, he
observes, firstly, that all animals tend to vary in some degree, and, secondly,
that agriculturists improve their domesticated animals by selection; and then,
he adds, but what is done in this latter case 'by art, seems to be done with
equal efficacy, though more slowly, by nature, in the formation of varieties of
mankind, fitted for the country which they inhabit. Of the accidental varieties
of man, which would occur among the first few and scattered inhabitants of the
middle regions of Africa, some one would be better fitted than the others to
bear the diseases of the country. This race would consequently multiply, while the
others would decrease; not only from their inability to sustain the attacks of
disease, but from their incapacity of contending with their more vigorous
neighbours. The colour of this vigorous race I take for granted, from what has
been already said, would be dark. But the same disposition to form varieties
still existing, a darker and a darker race would in the course of time occur:
and as the darkest would be the best fitted for the climate, this would at
length become the most prevalent; if not the only race, in the particular
country in which it had originated.' He then extends these same views to the
white inhabitants of colder climates. I am indebted to Mr Rowley, of the United
States, for having called my attention, through Mr Brace, to the above passage
in Dr Wells' work.
The Hon. and Rev. W. Herbert, afterwards Dean of Manchester, in the fourth
volume of the 'Horticultural Transactions,' 1822, and in his work on the
'Amaryllidaceae' (1837, pp. 19, 339), declares that 'horticultural experiments
have established, beyond the possibility of refutation, that botanical species
are only a higher and more permanent class of varieties.' He extends the same
view to animals. The Dean believes that single species of each genus were
created in an originally highly plastic condition, and that these have
produced, chiefly by intercrossing, but likewise by variation, all our existing
species.
In 1826 Professor Grant, in the concluding paragraph in his well-known paper
('Edinburgh philosophical journal,' vol. xiv. p. 283) on the Spongilla, clearly
declares his belief that species are descended from other species, and that
they become improved in the course of modification. This same view was given in
his 55th Lecture, published in the 'Lancet' in 1834.
In 1831 Mr Patrick Matthew published his work on 'Naval Timber and
Arboriculture,' in which he gives precisely the same view on the origin of
species as that (presently to be alluded to) propounded by Mr Wallace and
myself in the 'Linnean journal,' and as that enlarged in the present volume.
Unfortunately the view was given by Mr Matthew very briefly in scattered
passages in an Appendix to a work on a different subject, so that it remained
unnoticed until Mr Matthew himself drew attention to it in the 'Gardener's Chronicle,'
on April 7th, 1860. The differences of Mr Matthew's view from mine are not of
much importance; he seems to consider that the world was nearly depopulated at
successive periods, and then re-stocked; and he gives as an alternative, that
new forms may be generated ' without the presence of any mould or germ of
former aggregates.' I am not sure that I understand some passages; but it seems
that he attributes much influence to the direct action of the conditions of
life. He clearly saw, however, the full force of the principle of natural
selection.
The celebrated geologist and naturalist, Von Buch, in his excellent
'Description physique des Isles Canaries' (1836, p. 147), clearly expresses his
belief that varieties slowly become changed into permanent species, which are
no longer capable of intercrossing.
Rafinesque, in his 'New Flora of North America,' published in 1836, wrote
(p. 6) as follows:- 'All species might have been varieties once, and many
varieties are gradually becoming species by assuming constant and peculiar
characters'; but farther on (p. 18) he adds, 'except the original types or
ancestors of the genus.'
In 1843-44 Professor Haldeman ('Boston journal of Nat. Hist. U. States, vol.
iv. p. 468) has ably given the arguments for and against the hypothesis of the
development and modification of species: he seems to lean towards the side of
change.
The 'Vestiges of Creation' appeared in 1844. In the tenth and much improved
edition (1853) the anonymous author says (p. 155):- 'The proposition determined
on after much consideration is, that the several series of animated beings,
from the simplest and oldest up to the highest and most recent, are, under the
providence of God, the results, first, of an impulse which has been
imparted to the forms of life, advancing them, in definite times, by
generation, through grades of organisation terminating in the highest
dicotyledons- and vertebrata, these grades being few in number, and generally
marked by intervals of organic character, which we find to be a practical
difficulty in ascertaining affinities; second, of another impulse
connected with the vital forces, tending, in the course of generations, to
modify organic structures in accordance with external circumstances, as food,
the nature of the habitat, and the meteoric agencies, these being the
''adaptations'' of the natural theologian.' The author apparently believes that
organisation progresses by sudden leaps, but that the effects produced by the
conditions of life are gradual. He argues with much force on general grounds
that species are not immutable productions. But I cannot see how the two
supposed 'impulses' account in a scientific sense for the numerous and
beautiful co-adaptations which we see throughout nature; I cannot see that we
thus gain any insight how, for instance, a woodpecker has become adapted to its
peculiar habits of Life. The work, from its powerful and brilliant style,
though displaying in the earlier editions little accurate knowledge and a great
want of scientific caution, immediately had a very wide circulation. In my
opinion it has done excellent service in this country in calling attention to
the subject, in removing prejudice, and in thus preparing the ground for the
reception of analogous views.
In 1846 the veteran geologist N. J. d'Omalius d'Halloy published in an
excellent though short paper ("Bulletins de l'Acad. Roy Bruxelles,' tom.
xiii. p. 581) his opinion that it is more probable that new species have been
produced by descent with modification than that they have been separately
created: the author first promulgated this opinion in 1831.
Professor Owen, in 1849 ('Nature of Limbs,' p. 86), wrote as follows:-
"The archetypal idea was manifested in the flesh under diverse such
modifications, upon this planet, long prior to the existence of those animal
species that actually exemplify it. To what natural laws or secondary causes
the orderly succession and progression of such organic phenomena may have been
committed, we, as yet, are ignorant.' In his Address to the British
Association, in 1858, he speaks (p. li.) of "the axiom of the continuous
operation of creative power, or of the ordained becoming of living things.'
Farther on (p. xc.), after referring to geographical distribution, he adds,
'These phenomena shake our confidence in the conclusion that the Apteryx of New
Zealand and the Red Grouse of England were distinct creations in and for those
islands respectively. Always, also, it may be well to bear in mind that by the
word ''creation'' the zoologist means '"a process he knows not what.'' He
amplifies this idea by adding that when such cases as that of the Red Grouse
are enumerated by the zoologists as evidence of distinct creation of the bird
in and for such islands, he chiefly expresses that he knows not how the Red
Grouse came to be there, and there exclusively; signifying also, by this mode
of expressing such ignorance, his belief that both the bird and the islands
owed their origin to a great first Creative Cause.' If we interpret these
sentences given in the same Address, one by the other, it appears that this
eminent philosopher felt in 1858 his confidence shaken that the Apteryx and the
Red Grouse first appeared in their respective homes, 'he knew not how,' or by
some process 'he knew not what.'
This Address was delivered after the papers by Mr Wallace and myself on the
Origin of Species, presently to be referred to, had been read before the
Linnean Society. When the first edition of this work was published, I was so
completely deceived, as were many others, by such expressions as 'the
continuous operation of creative power,' that I included Professor Owen with
other palaeontologists as being firmly convinced of the immutability of
species; but it appears ('Anat. of Vertebrates,' vol. iii. p. 796) that this was
on my part a preposterous error. In the last edition of this work I inferred,
and the inference still seems to me perfectly just, from a passage beginning
with the words 'no doubt the type-form,' &c. (Ibid. vol. i. p. xxxv.), that
Professor Owen admitted that natural selection may have done something in the
formation of a new species; but this it appears (Ibid. vol. nl. p. 798) is
inaccurate and without evidence. I also gave some extracts from a
correspondence between Professor Owen and the Editor of the 'London Review,'
from which it appeared manifest to the Editor as well as to myself, that
Professor Owen claimed to have promulgated the theory of natural selection
before I had done so; and I expressed my surprise and satisfaction at this
announcement; but as far as it is possible to understand certain recently
published passages (Ibid. vol. iii. p. 798) I have either partially or wholly
again fallen into error. It is consolatory to me that others find Professor
Owen's controversial writings as difficult to understand and to reconcile with
each other, as I do. As far as the mere enunciation of the principle of natural
selection is concerned, it is quite immaterial whether or not Professor Owen
preceded me, for both of us, as shown in this historical sketch, were long ago
preceded by Dr Wells and Mr Matthews.
M. Isidore Geoffroy Saint-Hilaire, in his lectures delivered in 1850 (of
which a Résumé appeared in the 'Revue et Nag. de Zoolog.,' Jan. 1851), briefly
gives his reason for believing that specific characters "sont fixés, pour
chaque espèce, tant qu'elle se perpétue au milieu des mèmes circonstances: ils
se modifient, si les circonstances ambiantes viennent à changer.' 'En résumé, l'observation
des animaux sauvages démontre déjà la variabilité limité des espèces.
Les expériences sur les animaux sauvages devenus domestiques, et sur les
animaux domestiques redevenus sauvages, la démontrent plus clairement encore.
Ces memes expériences prouvent, de plus, que les différences produites peuvent
etre de valeur générique.' In his 'Hist. Nat. Généralé (tom. ii. p. 430,
1859) he amplifies analogous conclusions.
From a circular lately issued it appears that Dr Freke, in 1851
("Dublin Medical Press,' p. 322), propounded the doctrine that all organic
beings have descended from one primordial form. His grounds of belief and
treatment of the subject are wholly different from mine; but as Dr Freke has
now (1861) published his Essay on the 'Origin of Species by means of Organic
Affinity,' the difficult attempt to give any idea of his views would be
superfluous on my part.
Mr Herbert Spencer, in an Essay (originally published in the 'Leader,'
March, 1852, and republished in his 'Essays,' in 1858), has contrasted the
theories of the Creation and the Development of organic beings with remarkable
skill and force. He argues from the analogy of domestic productions, from the
changes which the embryos of many species undergo, from the difficulty of
distinguishing species and varieties, and from the principle of general
gradation, that species have been modified; and he attributes the modification
to the change of circumstances. The author (1855) has also treated psychology
on the principle of the necessary acquirement of each mental power and capacity
by gradation.
In 1852 M. Naudin, a distinguished botanist, expressly stated, in an
admirable paper on the Origin of Species ('Revue Horticole, p. 102; since
partly republished in the 'Nouvelles Archives du Muséum,' tom. i. p. 171), his
belief that species are formed in an analogous manner as varieties are under
cultivation; and the latter process he attributes to man's power of selection.
But he does not show how selection acts under nature. He believes, like Dean
Herbert, that species, when nascent, were more plastic than at present. He lays
weight on what he calls the principle of finality, 'puissance mystérieuse,
indéterminée; fatalité pour les uns; pour les autres volonté providentielle,
dont l'action incessante sur les ètres vivants détermine, à toutes les époques
de l'existence du monde, la forme, le volume, et la durée de chacun d'eux, en
raison de sa destinée dans l'ordre de choses dont il fait partie. C'est cette
puissance qui harmonise chaque membre à l'ensemble, en l'appropriant à la
fonction qu'il doit remplir dans l'organisme général de la nature, fonction qui
est pour lui sa raison d'ètre.'*
* From references in Bronn's 'Untersuchungen über die
Entwickenlungs-Gesetze,' it appears that the celebrated botanist and
palaeontologist Unger published, in 1852, his belief that species undergo
development and modification. Dalton, likewise, in Pander and Dalton's work on
Fossil Sloths, expressed, in 1821 a similar belief. Similar views have, as is
well known, been maintained by Oken in his mystical 'Natur-philosophie.' From
other references in Godron's work 'Sur l'Espéce,' it seems that Bory St
Vincent, Burdach, Poiret, and Fries, have all admitted that new species are
continually being produced.
In 1853 a celebrated geologist, Count Keyserling ("Bulletin de la Soc.
Gèolog.,' 2nd Ser., tom. x. p. 357), suggested that as new diseases, supposed
to have been caused by some miasma, have arisen and spread over the world, so
at certain periods the germs of existing species may have been chemically
affected by circumambient molecules of a particular nature, and thus have given
rise to new forms.
In this same year, 1853, Dr Schaaffhausen published an excellent pamphlet
('Verhand. des Naturhist. Vereins der preuss. Rheinlands,' &c.), in which
he maintains the development of organic forms on the earth. He infers that many
species have kept true for long periods, whereas a few have become modified.
The distinction of species he explains by the destruction of intermediate
graduated forms. 'Thus living plants and animals are not separated from the extinct
by new creations, but are to be regarded as their descendants through continued
reproduction.'
I may add, that of the thirty-four authors named in this Historical Sketch,
who believe in the modification of species, or at least disbelieve in separate acts
of creation, twenty-seven have written on special branches of natural history
or geology.
A well-known French botanist, M. Lecoq, writes in 1854 ('Etudes sur
Géograph. Bot.,' tom. i. p. 250), 'On voit que nos recherches sur la fixité ou
la variation de l'espèce, nous conduisent directement aux idées émises, par
deux hommes justement célèbres, Geoffroy Saint-Hilaire et Goethe.' Some other
passages scattered through M. Lecoq's large work, make it a little doubtful how
far he extends his views on the modification of species.
The 'Philosophy of Creation' has been treated in a masterly manner by the
Rev. Baden Powell, in his "Essays on the Unity of Worlds,' 1855. Nothing
can be more striking than the manner in which he shows that the introduction of
new species is "a regular, not a casual phenomenon,' or, as Sir John
Herschel expresses it, 'a natural in contradistinction to a miraculous,
process.'
The third volume of the "Journal of the Linnean Society' contains
papers, read July 1st, 1858, by Mr Wallace and myself, in which, as stated in
the introductory remarks to this volume, the theory of Natural Selection is
promulgated by Mr Wallace with admirable force and clearness.
Von Baer, towards whom all zoologists feel so profound a respect, expressed
about the year 1859 (see Prof. Rudolph Wagner, a
"Zoologisch-Anthropologische Untersuchungen,' 1861, s. 51) his conviction,
chiefly grounded on the laws of geographical distribution, that forms now
perfectly distinct have descended from a single parent-form.
In June, 1859, Professor Huxley gave a lecture before the Royal Institution
on the 'Persistent Types of Animal Life.' Referring to such cases, he remarks,
"It is difficult to comprehend the meaning of such facts as these, if we
suppose that each species of animal and plant, or each great type of
organisation, was formed and placed upon the surface of the globe at long
intervals by a distinct act of creative power; and it is well to recollect that
such an assumption is as unsupported by tradition or revelation as it is
opposed to the general analogy of nature. If, on the other hand, we view
'Persistent Types' in relation to that hypothesis which supposes the species
living at any time to be the result of the gradual modification of pre-existing
species a hypothesis which, though unproven, and sadly damaged by some of its
supporters, is yet the only one to which physiology lends any countenance;
their existence would seem to show that the amount of modification which living
beings have undergone during geological time is but very small in relation to
the whole series of changes which they have suffered.'
In December, 1859, Dr Hooker published his 'Introduction to the Australian
Flora.' In the first part of this great work he admits the truth of the descent
and modification of species, and supports this doctrine by many original
observations.
It has been seen in the last chapter
that amongst organic beings in a state of nature there is some individual
variability; indeed I am not aware that this has ever been disputed. It is
immaterial for us whether a multitude of doubtful forms be called species or
sub-species or varieties; what rank, for instance, the two or three hundred
doubtful forms of British plants are entitled to hold, if the existence of any
well-marked varieties be admitted. But the mere existence of individual
variability and of some few well-marked varieties, though necessary as the
foundation for the work, helps us but little in understanding how species arise
in nature. How have all those exquisite adaptations of one part of the
organisation to another part, and to the conditions of life, and of one
distinct organic being to another being, been perfected? We see these beautiful
co-adaptations most plainly in the woodpecker and missletoe; and only a little
less plainly in the humblest parasite which clings to the hairs of a quadruped
or feathers of a bird; in the structure of the beetle which dives through the
water; in the plumed seed which is wafted by the gentlest breeze; in short, we
see beautiful adaptations everywhere and in every part of the organic world.
Again, it may be asked, how is it that varieties, which I have called
incipient species, become ultimately converted into good and distinct species,
which in most cases obviously differ from each other far more than do the
varieties of the same species? How do those groups of species, which constitute
what are called distinct genera, and which differ from each other more than do
the species of the same genus, arise? All these results, as we shall more fully
see in the next chapter, follow inevitably from the struggle for life. Owing to
this struggle for life, any variation, however slight and from whatever cause
proceeding, if it be in any degree profitable to an individual of any species,
in its infinitely complex relations to other organic beings and to external
nature, will tend to the preservation of that individual, and will generally be
inherited by its offspring. The offspring, also, will thus have a better chance
of surviving, for, of the many individuals of any species which are
periodically born, but a small number can survive. I have called this
principle, by which each slight variation, if useful, is preserved, by the term
of Natural Selection, in order to mark its relation to man's power of
selection. We have seen that man by selection can certainly produce great
results, and can adapt organic beings to his own uses, through the accumulation
of slight but useful variations, given to him by the hand of Nature. But
Natural Selection, as we shall hereafter see, is a power incessantly ready for
action, and is as immeasurably superior to man's feeble efforts, as the works
of Nature are to those of Art.
We will now discuss in a little more detail the struggle for existence. In
my future work this subject shall be treated, as it well deserves, at much greater
length. The elder De Candolle and Lyell have largely and philosophically shown
that all organic beings are exposed to severe competition. In regard to plants,
no one has treated this subject with more spirit and ability than W. Herbert,
Dean of Manchester, evidently the result of his great horticultural knowledge.
Nothing is easier than to admit in words the truth of the universal struggle
for life, or more difficult at least I have found it so than constantly to bear
this conclusion in mind. Yet unless it be thoroughly engrained in the mind, I
am convinced that the whole economy of nature, with every fact on distribution,
rarity, abundance, extinction, and variation, will be dimly seen or quite
misunderstood. We behold the face of nature bright with gladness, we often see
superabundance of food; we do not see, or we forget, that the birds which are
idly singing round us mostly live on insects or seeds, and are thus constantly
destroying life; or we forget how largely these songsters, or their eggs, or their
nestlings are destroyed by birds and beasts of prey; we do not always bear in
mind, that though food may be now superabundant, it is not so at all seasons of
each recurring year.
I should premise that I use the term Struggle for Existence in a large and
metaphorical sense, including dependence of one being on another, and including
(which is more important) not only the life of the individual, but success in
leaving progeny. Two canine animals in a time of dearth, may be truly said to
struggle with each other which shall get food and live. But a plant on the edge
of a desert is said to struggle for life against the drought, though more
properly it should be said to be dependent on the moisture. A plant which
annually produces a thousand seeds, of which on an average only one comes to
maturity, may be more truly said to struggle with the plants of the same and
other kinds which already clothe the ground. The missletoe is dependent on the
apple and a few other trees, but can only in a far-fetched sense be said to
struggle with these trees, for if too many of these parasites grow on the same
tree, it will languish and die. But several seedling missletoes, growing close
together on the same branch, may more truly be said to struggle with each
other. As the missletoe is disseminated by birds, its existence depends on
birds; and it may metaphorically be said to struggle with other fruit-bearing
plants, in order to tempt birds to devour and thus disseminate its seeds rather
than those of other plants. In these several senses, which pass into each
other, I use for convenience sake the general term of struggle for existence.
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