Darwin’s Claim to Descent with Modification
MR. ALLEN, in his “Charles Darwin,” {168a} says that “in the public mind
Mr. Darwin is commonly regarded as the discoverer and founder of the
evolution hypothesis,” and on p. 177 he says that to most men Darwinism
and evolution mean one and the same thing. Mr. Allen declares
misconception on this matter to be “so extremely general” as to be
“almost universal;” this is more true than creditable to Mr. Darwin.
Mr. Allen says {168b} that though Mr. Darwin gained “far wider general
acceptance” for both the doctrine of descent in general, and for that of
the descent of man from a simious or semi-simious ancestor in particular,
“he laid no sort of claim to originality or proprietorship in either
theory.” This is not the case. No one can claim a theory more
frequently and more effectually than Mr. Darwin claimed descent with
modification, nor, as I have already said, is it likely that the
misconception of which Mr. Allen complains would be general, if he had
not so claimed it. The “Origin of Species” begins:—
“When on board H.M.S. _Beagle_, as naturalist, I was much struck with
certain facts in the distribution of the inhabitants of South America,
and in the geological relation of the present to the past inhabitants of
that continent. These facts seemed to me to throw some light on the
origin of species—that mystery of mysteries, as it has been called by one
of our greatest philosophers. On my return home it occurred to me, in
1837, that something might perhaps be made out on this question by
patiently accumulating and reflecting upon all sorts of facts which could
possibly have any bearing on it. After five years’ work I allowed myself
to speculate upon the subject, and drew up some short notes; these I
enlarged in 1844 {169a} into a sketch of the conclusions which then
seemed to me probable. From that period to the present day I have
steadily pursued the same object. I hope I may be excused these personal
details, as I give them to show that I have not been hasty in coming to a
decision.”
This is bland, but peremptory. Mr. Darwin implies that the mere asking
of the question how species has come about opened up a field into which
speculation itself had hardly yet ventured to intrude. It was the
mystery of mysteries; one of our greatest philosophers had said so; not
one little feeble ray of light had ever yet been thrown upon it. Mr.
Darwin knew all this, and was appalled at the greatness of the task that
lay before him; still, after he had pondered on what he had seen in South
America, it really did occur to him, that if he was very very patient,
and went on reflecting for years and years longer, upon all sorts of
facts, good, bad, and indifferent, which could possibly have any bearing
on the subject—and what fact might not possibly have some bearing?—well,
something, as against the nothing that had been made out hitherto, might
by some faint far-away possibility be one day dimly seem. It was only
what he had seen in South America that made all this occur to him. He
had never seen anything about descent with modification in any book, nor
heard any one talk about it as having been put forward by other people;
if he had, he would, of course, have been the first to say so; he was not
as other philosophers are; so the mountain went on for years and years
gestating, but still there was no labour.
“My work,” continues Mr. Darwin, “is now nearly finished; but as it will
take me two or three years to complete it, and as my health is far from
strong, I have been urged to publish this abstract. I have been more
especially induced to do this, as Mr. Wallace, who is now studying the
natural history of the Malay Archipelago, has arrived at almost exactly
the same general conclusions that I have on the origin of species.” Mr.
Darwin was naturally anxious to forestall Mr. Wallace, and hurried up
with his book. What reader, on finding descent with modification to be
its most prominent feature, could doubt—especially if new to the subject,
as the greater number of Mr. Darwin’s readers in 1859 were—that this same
descent with modification was the theory which Mr. Darwin and Mr. Wallace
had jointly hit upon, and which Mr. Darwin was so anxious to show that he
had not been hasty in adopting? When Mr. Darwin went on to say that his
abstract would be very imperfect, and that he could not give references
and authorities for his several statements, we did not suppose that such
an apology could be meant to cover silence concerning writers who during
their whole lives, or nearly so, had borne the burden and heat of the day
in respect of descent with modification in its most extended application.
“I much regret,” says Mr. Darwin, “that want of space prevents my having
the satisfaction of acknowledging the generous assistance I have received
from very many naturalists, some of them personally unknown to me.” This
is like what the Royal Academicians say when they do not intend to hang
our pictures; they can, however, generally find space for a picture if
they want to hang it, and we assume with safety that there are no
master-works by painters of the very highest rank for which no space has
been available. Want of space will, indeed, prevent my quoting from more
than one other paragraph of Mr. Darwin’s introduction; this paragraph,
however, should alone suffice to show how inaccurate Mr. Allen is in
saying that Mr. Darwin “laid no sort of claim to originality or
proprietorship” in the theory of descent with modification, and this is
the point with which we are immediately concerned. Mr. Darwin says:—
“In considering the origin of species, it is quite conceivable that a
naturalist, reflecting on the mutual affinities of organic beings, on
their embryological relations, their geographical distribution,
geological succession, and other such facts, might come to the conclusion
that each species had not been independently created, but had descended
like varieties from other species.”
It will be observed that not only is no hint given here that descent with
modification was a theory which, though unknown to the general public,
had been occupying the attention of biologists for a hundred years and
more, but it is distinctly implied that this was not the case. When Mr.
Darwin said it was “conceivable that a naturalist might” arrive at the
theory of descent, straightforward readers took him to mean that though
this was conceivable, it had never, to Mr. Darwin’s knowledge, been done.
If we had a notion that we had already vaguely heard of the theory that
men and the lower animals were descended from common ancestors, we must
have been wrong; it was not this that we had heard of, but something
else, which, though doubtless a little like it, was all wrong, whereas
this was obviously going to be all right.
To follow the rest of the paragraph with the closeness that it merits
would be a task at once so long and so unpleasant that I will omit
further reference to any part of it except the last sentence. That
sentence runs:—
“In the case of the mistletoe, which draws its nourishment from certain
trees, which has seeds that must be transported by certain birds, and
which has flowers with separate sexes absolutely requiring the agency of
certain insects to bring pollen from one flower to the other, it is
equally preposterous to account for the structure of this parasite, with
its relations to several distinct organic beings, by the effects of the
external conditions, or of habit, or of the volition of the plant
itself.”
Doubtless it would be preposterous to refer the structure of either
woodpecker or mistletoe to the single agency of any one of these three
causes; but neither Lamarck nor any other writer on evolution has, so far
as I know, even contemplated this; the early evolutionists supposed
organic modification to depend on the action and interaction of all
three, and I venture to think that this will ere long be considered as,
to say the least of it, not more preposterous than the assigning of the
largely preponderating share in the production of such highly and
variously correlated organisms as the mistletoe and woodpecker mainly to
luck pure and simple, as is done by Mr. Charles Darwin’s theory.
It will be observed that in the paragraph last quoted from, Mr. Darwin,
_more suo_, is careful not to commit himself. All he has said is, that
it would be preposterous to do something the preposterousness of which
cannot be reasonably disputed; the impression, however, is none the less
effectually conveyed, that some one of the three assigned agencies, taken
singly, was the only cause of modification ever yet proposed, if, indeed,
any writer had even gone so far as this. We knew we did not know much
about the matter ourselves, and that Mr. Darwin was a naturalist of long
and high standing; we naturally, therefore, credited him with the same
good faith as a writer that we knew in ourselves as readers; it never so
much as crossed our minds to suppose that the head which he was holding
up all dripping before our eyes as that of a fool, was not that of a fool
who had actually lived and written, but only of a figure of straw which
had been dipped in a bucket of red paint. Naturally enough we concluded,
since Mr. Darwin seemed to say so, that if his predecessors had nothing
better to say for themselves than this, it would not be worth while to
trouble about them further; especially as we did not know who they were,
nor what they had written, and Mr. Darwin did not tell us. It would be
better and less trouble to take the goods with which it was plain Mr.
Darwin was going to provide us, and ask no questions. We have seen that
even tolerably obvious conclusions were rather slow in occurring to poor
simple-minded Mr. Darwin, and may be sure that it never once occurred to
him that the British public would be likely to argue thus; he had no
intention of playing the scientific confidence trick upon us. I dare say
not, but unfortunately the result has closely resembled the one that
would have ensued if Mr. Darwin had had such an intention.
The claim to originality made so distinctly in the opening sentences of
the “Origin of Species” is repeated in a letter to Professor Haeckel,
written October 8, 1864, and giving an account of the development of his
belief in descent with modification. This letter, part of which is
quoted by Mr. Allen, {173a} is given on p. 134 of the English translation
of Professor Haeckel’s “History of Creation,” {173b} and runs as
follows:—
“In South America three classes of facts were brought strongly before my
mind. Firstly, the manner in which closely allied species replace
species in going southward. Secondly, the close affinity of the species
inhabiting the islands near South America to those proper to the
continent. This struck me profoundly, especially the difference of the
species in the adjoining islets in the Galapagos Archipelago. Thirdly,
the relation of the living Edentata and Rodentia to the extinct species.
I shall never forget my astonishment when I dug out a gigantic piece of
armour like that of the living armadillo.
“Reflecting on these facts, and collecting analogous ones, it seemed to
me probable that allied species were descended from a common ancestor.
But during several years I could not conceive how each form could have
been modified so as to become admirably adapted to its place in nature.
I began, therefore, to study domesticated animals and cultivated plants,
and after a time perceived that man’s power of selecting and breeding
from certain individuals was the most powerful of all means in the
production of new races. Having attended to the habits of animals and
their relations to the surrounding conditions, I was able to realise the
severe struggle for existence to which all organisms are subjected, and
my geological observations had allowed me to appreciate to a certain
extent the duration of past geological periods. Therefore, when I
happened to read Malthus on population, the idea of natural selection
flashed on me. Of all minor points, the last which I appreciated was the
importance and cause of the principle of divergence.”
This is all very naïve, and accords perfectly with the introductory
paragraphs of the “Origin of Species;” it gives us the same picture of a
solitary thinker, a poor, lonely, friendless student of nature, who had
never so much as heard of Buffon, Erasmus Darwin, or Lamarck.
Unfortunately, however, we cannot forget the description of the
influences which, according to Mr. Grant Allen, did in reality surround
Mr. Darwin’s youth, and certainly they are more what we should have
expected than those suggested rather than expressly stated by Mr. Darwin.
“Everywhere around him,” says Mr. Allen, {174a} “in his childhood and
youth these great but formless” (why “formless”?) “evolutionary ideas
were brewing and fermenting. The scientific society of his elders and of
the contemporaries among whom he grew up was permeated with the leaven of
Laplace and Lamarck, of Hutton and of Herschel. Inquiry was especially
everywhere rife as to the origin and nature of specific distinctions
among plants and animals. Those who believed in the doctrine of Buffon
and of the ‘Zoonomia,’ and those who disbelieved in it, alike, were
profoundly interested and agitated in soul by the far-reaching
implications of that fundamental problem. On every side evolutionism, in
its crude form.” (I suppose Mr. Allen could not help saying “in its
crude form,” but descent with modification in 1809 meant, to all intents
and purposes, and was understood to mean, what it means now, or ought to
mean, to most people.) “The universal stir,” says Mr. Allen on the
following page, “and deep prying into evolutionary questions which
everywhere existed among scientific men in his early days was naturally
communicated to a lad born of a scientific family and inheriting directly
in blood and bone the biological tastes and tendencies of Erasmus
Darwin.”
I confess to thinking that Mr. Allen’s account of the influences which
surrounded Mr. Darwin’s youth, if tainted with picturesqueness, is still
substantially correct. On an earlier page he had written:—“It is
impossible to take up any scientific memoirs or treatises of the first
half of our own century without seeing at a glance how every mind of high
original scientific importance was permeated and disturbed by the
fundamental questions aroused, but not fully answered, by Buffon,
Lamarck, and Erasmus Darwin. In Lyell’s letters, and in Agassiz’s
lectures, in the ‘Botanic Journal’ and in the ‘Philosophical
Transactions,’ in treatises on Madeira beetles and the Australian flora,
we find everywhere the thoughts of men profoundly influenced in a
thousand directions by this universal evolutionary solvent and leaven.
“And while the world of thought was thus seething and moving restlessly
before the wave of ideas set in motion by these various independent
philosophers, another group of causes in another field was rendering
smooth the path beforehand for the future champion of the amended
evolutionism. Geology on the one hand and astronomy on the other were
making men’s minds gradually familiar with the conception of slow natural
development, as opposed to immediate and miraculous creation.
. . .
“The influence of these novel conceptions upon the growth and spread of
evolutionary ideas was far-reaching and twofold. In the first place, the
discovery of a definite succession of nearly related organic forms
following one another with evident closeness through the various ages,
inevitably suggested to every inquiring observer the possibility of their
direct descent one from the other. In the second place, the discovery
that geological formations were not really separated each from its
predecessor by violent revolutions, but were the result of gradual and
ordinary changes, discredited the old idea of frequent fresh creations
after each catastrophe, and familiarised the minds of men of science with
the alternative notion of slow and natural evolutionary processes. The
past was seen in effect to be the parent of the present; the present was
recognised as the child of the past.”
This is certainly not Mr. Darwin’s own account of the matter. Probably
the truth will lie somewhere between the two extreme views: and on the
one hand, the world of thought was not seething quite so badly as Mr.
Allen represents it, while on the other, though “three classes of fact,”
&c., were undoubtedly “brought strongly before” Mr. Darwin’s “mind in
South America,” yet some of them had perhaps already been brought before
it at an earlier time, which he did not happen to remember at the moment
of writing his letter to Professor Haeckel and the opening paragraph of
the “Origin of Species.”