The Origin of Species
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Thomas H. Huxley >> The Origin of Species
In the remainder of Mr. Darwin's argument our own private ingenuity has
not hitherto enabled us to pick holes of any great importance; and
judging by what we hear and read, other adventurers in the same field
do not seem to have been much more fortunate. It has been urged, for
instance, that in his chapters on the struggle for existence and on
natural selection, Mr. Darwin does not so much prove that natural
selection does occur, as that it must occur; but, in fact, no other
sort of demonstration is attainable. A race does not attract our
attention in Nature until it has, in all probability, existed for a
considerable time, and then it is too late to inquire into the
conditions of its origin. Again, it is said that there is no real
analogy between the selection which takes place under domestication, by
human influence, and any operation which can be effected by Nature, for
man interferes intelligently. Reduced to its elements, this argument
implies that an effect produced with trouble by an intelligent agent
must, 'a fortiori', be more troublesome, if not impossible, to an
unintelligent agent. Even putting aside the question whether Nature,
acting as she does according to definite and invariable laws, can be
rightly called an unintelligent agent, such a position as this is wholly
untenable. Mix salt and sand, and it shall puzzle the wisest of men,
with his mere natural appliances, to separate all the grains of sand
from all the grains of salt; but a shower of rain will effect the same
object in ten minutes. And so, while man may find it tax all his
intelligence to separate any variety which arises, and to breed
selectively from it, the destructive agencies incessantly at work in
Nature, if they find one variety to be more soluble in circumstances
than the other, will inevitably, in the long run, eliminate it.
A frequent and a just objection to the Lamarckian hypothesis of the
transmutation of species is based upon the absence of transitional
forms between many species. But against the Darwinian hypothesis this
argument has no force. Indeed, one of the most valuable and suggestive
parts of Mr. Darwin's work is that in which he proves, that the frequent
absence of transitions is a necessary consequence of his doctrine, and
that the stock whence two or more species have sprung, need in no
respect be intermediate between these species. If any two species
have arisen from a common stock in the same way as the carrier and the
pouter, say, have arisen from the rock-pigeon, then the common stock of
these two species need be no more intermediate between the two than the
rock-pigeon is between the carrier and pouter. Clearly appreciate the
force of this analogy, and all the arguments against the origin of
species by selection, based on the absence of transitional forms, fall
to the ground. And Mr. Darwin's position might, we think, have been
even stronger than it is if he had not embarrassed himself with the
aphorism, "Natura non facit saltum," which turns up so often in his
pages. We believe, as we have said above, that Nature does make jumps
now and then, and a recognition of the fact is of no small importance
in disposing of many minor objections to the doctrine of
transmutation.
But we must pause. The discussion of Mr. Darwin's arguments in detail
would lead us far beyond the limits within which we proposed, at
starting, to confine this article. Our object has been attained if we
have given an intelligible, however brief, account of the established
facts connected with species, and of the relation of the explanation of
those facts offered by Mr. Darwin to the theoretical views held by his
predecessors and his contemporaries, and, above all, to the
requirements of scientific logic. We have ventured to point out that it
does not, as yet, satisfy all those requirements; but we do not
hesitate to assert that it is as superior to any preceding or
contemporary hypothesis, in the extent of observational and experimental
basis on which it rests, in its rigorously scientific method, and in
its power of explaining biological phenomena, as was the hypothesis of
Copernicus to the speculations of Ptolemy. But the planetary orbits
turned out to be not quite circular after all, and, grand as was the
service Copernicus rendered to science, Kepler and Newton had to come
after him. What if the orbit of Darwinism should be a little too
circular? What if species should offer residual phenomena, here and
there, not explicable by natural selection? Twenty years hence
naturalists may be in a position to say whether this is, or is not, the
case; but in either event they will owe the author of 'The Origin of
Species' an immense debt of gratitude. We should leave a very wrong
impression on the reader's mind if we permitted him to suppose that the
value of that work depends wholly on the ultimate justification of the
theoretical views which it contains. On the contrary, if they were
disproved to-morrow, the book would still be the best of its kind--the
most compendious statement of well-sifted facts bearing on the doctrine
of species that has ever appeared. The chapters on Variation, on the
Struggle for Existence, on Instinct, on Hybridism, on the Imperfection
of the Geological Record, on Geographical Distribution, have not only
no equals, but, so far as our knowledge goes, no competitors, within
the range of biological literature. And viewed as a whole, we do not
believe that, since the publication of Von Baer's Researches on
Development, thirty years ago, any work has appeared calculated to
exert so large an influence, not only on the future of Biology, but in
extending the domination of Science over regions of thought into which
she has, as yet, hardly penetrated.