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ment is, however, more plausible. The uncertainty of opinion among naturalists as to which are species and which varieties, is one of Mr. Darwin's very strong arguments that these two names cannot belong to things quite distinct in nature and origin. The reviewer says that this argument is of no weight, because the works of man present exactly the same phenomena ; and he instances patent inventions, and the excessive difficulty of determining whether they are new or old. I accept the analogy, though it is a very imperfect one, and maintain that, such as it is, it is all in favour of Mr. Darwin's views. For are not all inventions of the same kind directly affiliated to a common ancestor? Are not improved steam-engines or clocks the lineal descendants of some existing steam-engine or clock ? Is there ever a new creation in art or science any more than in nature ? Did ever patentee absolutely originate any complete and entire invention, no portion of which was derived from anything that had been made or described before? It is therefore clear that the difficulty of distinguishing the various classes of inventions which claim to be new, is of the same nature as the difficulty of distinguishing varieties and species, because neither are absolutely new creations, but both are alike descendants of pre-existing forms, from which and from each other they differ by varying and often imperceptible degrees. It appears, then, that however plausible this writer's objections may seem, whenever he descends from generalities to any specific statement, his supposed difficulties turn out to be in reality strongly confirmatory of Mr. Darwin's view.
The TIMES on Natural Selection The extraordinary misconception of the whole subject by popular writers and reviewers is well shown by an article which appeared in the Times newspaper on "The Reign of Law.” Alluding to the supposed economy of nature, in the adaptation of each species to its own place and its special use, the reviewer remarks : “To this universal law of the greatest economy, the law of natural selection stands in direct antagonism as the law of greatest possible waste of time and of creative power. To conceive a duck with webbed feet and a spoon-shaped bill, living by suction, to pass naturally
into a gull with webbed feet and a knife-like bill, living on flesh, in the longest possible time and in the most laborious possible way, we may conceive it to pass from the one to the other state by natural selection. The battle of life the ducks will have to fight will increase in peril continually as they cease (with the change of their bill) to be ducks, and attain a maximum of danger in the condition in which they begin to be gulls; and ages must elapse and whole generations must perish, and countless generations of the one species be created and sacrificed, to arrive at one single pair of the other.”
In this passage the theory of natural selection is so absurdly misrepresented that it would be amusing, did we not consider the misleading effect likely to be produced by this kind of teaching in so popular a journal. It is assumed that the duck and the gull are essential parts of nature, each well fitted for its place, and that if one had been produced from the other by a gradual metamorphosis, the intermediate forms would have been useless, unmeaning, and unfitted for any place in the system of the universe. Now, this idea can only exist in a mind ignorant of the very foundation and essence of the theory of natural selection, which is, the preservation of useful variations only, or, as has been well expressed, in other words, the “survival of the fittest.” Every intermediate form which could possibly have arisen during the transition from the duck to the gull, so far from having an unusually severe battle to fight for existence, or incurring any “maximum of danger," would necessarily have been as accurately adjusted to the rest of nature, and as well fitted to maintain and to enjoy its existence, as the duck or the gull actually are. If it were not so, it never could have been produced under the law of natural selection.
Intermediate or generalised Forms of extinct Animals, an
indication of Transmutation or Development The misconception of this writer illustrates another point very frequently overlooked. It is an essential part of Mr. Darwin's theory that one existing animal has not been derived from any other existing animal, but that both are the descendants of a common ancestor, which was at once different from either, but, in essential characters, to some extent intermediate between them both. The illustration of the duck and the gull is therefore misleading; one of these birds has not been derived from the other, but both from a common ancestor. This is not a mere supposition invented to support the theory of natural selection, but is founded on a variety of indisputable facts. As we go back into past time, and meet with the fossil remains of more and more ancient races of extinct animals, we find that many of them actually are intermediate between distinct groups of existing animals. Professor Owen continually dwells on this fact: he says in his Palæontology, p. 284: "A more generalised vertebrate structure is illustrated, in the extinct reptiles, by the affinities to ganoid fishes, shown by Ganocephala, Labyrinthodontia, and Ichthyopterygia ; by the affinities of the Pterosauria to birds, and by the approximation of the Dinosauria to mammals. (These have been recently shown by Professor Huxley to have more affinity to birds.) It is manifested by the combination of modern crocodilian, chelonian, and lacertian characters in the Cryptodontia and the Dicynodontia, and by the combined lacertian and crocodilian characters in the Thecodontia and Sauropterygia.” In the same work he tells us that “the Anoplotherium, in several important characters, resembled the embryo Ruminant, but retained throughout life those marks of adhesion to a generalised mammalian type;" and assures us that he has “never omitted a proper opportunity for impressing the results of observations showing the more generalised structures of extinct as compared with the more specialised forms of recent animals.” Modern palæontologists have discovered hundreds of examples of these more generalised or ancestral types. In the time of Cuvier, the Ruminants and the Pachyderms were looked upon as two of the most distinct orders of animals; but it is now demonstrated that there once existed a variety of genera and species, connecting by almost imperceptible grades such widely different animals as the pig and the camel. Among living quadrupeds we can scarcely find a more isolated group than the genus Equus, comprising the horses, asses, and zebras ; but through many species of Paloplotherium, Hippotherium, and Hipparion, and numbers of extinct forms of Equus found in Europe, India, and America, an almost complete transition is established with the Eocene Anoplotherium and Paleotherium, which are also generalised or ancestral types of the tapir and rhinoceros. The recent researches of M. Gaudry in Greece have furnished much new evidence of the same character. In the Miocene (or Pliocene) beds of Pikermi he has discovered the group of the Simocyonidæ intermediate between bears and wolves; the genus Hyænictis which connects the hyænas with the civets ; the Ancylotherium, which is allied both to the extinct mastodon and to the living pangolin or scaly ant-eater; and the Helladotherium, which connects the now isolated giraffe with the deer and antelops.
Between reptiles and fishes an intermediate type has been found in the Archegosaurus of the Coal formation; while the Labyrinthodon of the Trias combined characters of the Batrachia with those of crocodiles, lizards, and ganoid fishes. Even birds, the most apparently isolated of all living forms, and the most rarely preserved in a fossil state, have been shown to possess undoubted affinities with reptiles; and in the Oolitic Archæopteryx, with its lengthened tail, feathered on each side, we have one of the connecting links from the side of birds ; while Professor Huxley has recently shown that the entire order of Dinosaurians have remarkable affinities to birds, and that one of them, the Compsognathus, makes a nearer approach to bird organisation than does Archæopteryx to that of reptiles.
Analogous facts to these occur in other classes of animals, as an example of which we have the authority of a distinguished paleontologist, M. Barande, quoted by Mr. Darwin, for the statement that although the Palæozoic Invertebrata can certainly be classed under existing groups, yet at this ancient period the groups were not so distinctly separated from each other as they are now; while Mr. Scudder tells us that some of the fossil insects discovered in the Coal formation of America offer characters intermediate between those of existing orders. Agassiz, again, insists strongly that the more ancient animals resemble the embryonic forms of existing species; but as the embryos of distinct groups are known to resemble each other more than the adult animals (and in fact to be undistinguishable at a very early age), this is the same as saying that the ancient animals are exactly what, on Darwin's theory, the ancestors of existing animals ought to be; and this, it must be remembered, is the evidence of one of the strongest opponents of the theory of natural selection.
Conclusion I have thus endeavoured to meet fairly, and to answer plainly, a few of the most common objections to the theory of natural selection, and I have done so in every case by referring to admitted facts and to logical deductions from those facts.
As an indication and general summary of the line of argument I have adopted, I here give a brief demonstration in a tabular form of the Origin of Species by means of Natural Selection, referring for the facts to Mr. Darwin's works, and to the pages in this volume, where they are more or less fully treated.
A Demonstration of the Origin of Species by Natural Selection PROVED FACTS
(afterwards taken as Proved Facts) RAPID INCREASE OF ORGANISMS,
STRUGGLE FOR EXISTENCE, the pp. 23, 142 (Origin of Species, p. 75, 5th ed.)
deaths equalling the births on TOTAL NUMBER OF INDIVIDUALS
the average, p. 24 (Origin of STATIONARY, P. 23.
Specics, chap. iii.) STRUGGLE FOR EXISTENCE.
SURVIVAL OF THE FITTEST, or HEREDITY WITH VARIATION, or Natural Selection; meaning,
general likeness with individual simply, that on the whole those differences of parents and off- die who are least fitted to mainsprings, pp. 142, 156, 179 (Origin tain their existence (Origin of of Species, chaps. i. ii. v.)
Species, chap. iv.)
keep them in harmony with the
Changed Conditions ; and as the SURVIVAL OF THE FITTEST.
changes of conditions are permanCHANGE OF EXTERNAL CONDITIONS, ent changes, in the sense of not
universal and unceasing. —See reverting back to identical preLyell's Principles of Geology. vious conditions, the changes of
organic forms must be in the same sense permanent, and thus originate SPECIES.