The Foundations of the Origin of Species

Before concluding it will be well to show, although this has incidentally appeared, how far the theory of common descent can legitimately be extended[517 - This corresponds to a paragraph in the Origin, Ed. i. p. 483, vi. p. 662, where it is assumed that animals have descended “from at most only four or five progenitors, and plants from an equal or lesser number.” In the Origin, however, the author goes on, Ed. i. p. 484, vi. p. 663: “Analogy would lead me one step further, namely, to the belief that all animals and plants have descended from some one prototype.”]. If we once admit that two true species of the same genus can have descended from the same parent, it will not be possible to deny that two species of two genera may also have descended from a common stock. For in some families the genera approach almost as closely as species of the same genus; and in some orders, for instance in the monocotyledonous plants, the families run closely into each other. We do not hesitate to assign a common origin to dogs or cabbages, because they are divided into groups analogous to the groups in nature. Many naturalists indeed admit that all groups are artificial; and that they depend entirely on the extinction of intermediate species. Some naturalists, however, affirm that though driven from considering sterility as the characteristic of species, that an entire incapacity to propagate together is the best evidence of the existence of natural genera. Even if we put on one side the undoubted fact that some species of the same genus will not breed together, we cannot possibly admit the above rule, seeing that the grouse and pheasant (considered by some good ornithologists as forming two families), the bull-finch and canary-bird have bred together.

No doubt the more remote two species are from each other, the weaker the arguments become in favour of their common descent. In species of two distinct families the analogy, from the variation of domestic organisms and from the manner of their intermarrying, fails; and the arguments from their geographical distribution quite or almost quite fails. But if we once admit the general principles of this work, as far as a clear unity of type can be made out in groups of species, adapted to play diversified parts in the economy of nature, whether shown in the structure of the embryonic or mature being, and especially if shown by a community of abortive parts, we are legitimately led to admit their community of descent. Naturalists dispute how widely this unity of type extends: most, however, admit that the vertebrata are built on one type; the articulata on another; the mollusca on a third; and the radiata on probably more than one. Plants also appear to fall under three or four great types. On this theory, therefore, all the organisms yet discovered are descendants of probably less than ten parent-forms.

Conclusion

My reasons have now been assigned for believing that specific forms are not immutable creations[518 - This sentence corresponds, not to the final section of the Origin, Ed. i. p. 484, vi. p. 664, but rather to the opening words of the section already referred to (Origin, Ed. i. p. 480, vi. p. 657).]. The terms used by naturalists of affinity, unity of type, adaptive characters, the metamorphosis and abortion of organs, cease to be metaphorical expressions and become intelligible facts. We no longer look at an organic being as a savage does at a ship[519 - This simile occurs in the Essay of 1842, p. 50 (#FNanchor_177_177), and in the Origin, Ed. i. p. 485, vi. p. 665, i. e. in the final section of Ch. XIV (vi. Ch. XV). In the MS. there is some erasure in pencil of which I have taken no notice.] or other great work of art, as at a thing wholly beyond his comprehension, but as a production that has a history which we may search into. How interesting do all instincts become when we speculate on their origin as hereditary habits, or as slight congenital modifications of former instincts perpetuated by the individuals so characterised having been preserved. When we look at every complex instinct and mechanism as the summing up of a long history of contrivances, each most useful to its possessor, nearly in the same way as when we look at a great mechanical invention as the summing up of the labour, the experience, the reason, and even the blunders of numerous workmen. How interesting does the geographical distribution of all organic beings, past and present, become as throwing light on the ancient geography of the world. Geology loses glory[520 - An almost identical sentence occurs in the Origin, Ed. i. p. 487, vi. p. 667. The fine prophecy (in the Origin, Ed. i. p. 486, vi. p. 666) on “the almost untrodden field of inquiry” is wanting in the present Essay.] from the imperfection of its archives, but it gains in the immensity of its subject. There is much grandeur in looking at every existing organic being either as the lineal successor of some form now buried under thousands of feet of solid rock, or as being the co-descendant of that buried form of some more ancient and utterly lost inhabitant of this world. It accords with what we know of the laws impressed by the Creator[521 - See the last paragraph on p. 488 of the Origin, Ed. i., vi. p. 668.] on matter that the production and extinction of forms should, like the birth and death of individuals, be the result of secondary means. It is derogatory that the Creator of countless Universes should have made by individual acts of His will the myriads of creeping parasites and worms, which since the earliest dawn of life have swarmed over the land and in the depths of the ocean. We cease to be astonished[522 - A passage corresponding to this occurs in the sketch of 1842, p. 51 (#FNanchor_179_179), but not in the last chapter of the Origin.] that a group of animals should have been formed to lay their eggs in the bowels and flesh of other sensitive beings; that some animals should live by and even delight in cruelty; that animals should be led away by false instincts; that annually there should be an incalculable waste of the pollen, eggs and immature beings; for we see in all this the inevitable consequences of one great law, of the multiplication of organic beings not created immutable. From death, famine, and the struggle for existence, we see that the most exalted end which we are capable of conceiving, namely, the creation of the higher animals[523 - This sentence occurs in an almost identical form in the Origin, Ed. i. p. 490, vi. p. 669. It will be noted that man is not named though clearly referred to. Elsewhere (Origin, Ed. i. p. 488) the author is bolder and writes “Light will be thrown on the origin of man and his history.” In Ed. vi. p. 668, he writes “Much light &c.”], has directly proceeded. Doubtless, our first impression is to disbelieve that any secondary law could produce infinitely numerous organic beings, each characterised by the most exquisite workmanship and widely extended adaptations: it at first accords better with our faculties to suppose that each required the fiat of a Creator. There[524 - For the history of this sentence (with which the Origin of Species closes) see the Essay of 1842, p. 52, note 2 (#cn_183): also the concluding pages of the Introduction (#pgepubid00003).] is a [simple] grandeur in this view of life with its several powers of growth, reproduction and of sensation, having been originally breathed into matter under a few forms, perhaps into only one[525 - These four words are added in pencil between the lines.], and that whilst this planet has gone cycling onwards according to the fixed laws of gravity and whilst land and water have gone on replacing each other – that from so simple an origin, through the selection of infinitesimal varieties, endless forms most beautiful and most wonderful have been evolved.

notes

1

See the extracts in Life and Letters of Charles Darwin, ii. p. 5.

2

The second volume, – especially important in regard to Evolution, – reached him in the autumn of 1832, as Prof. Judd has pointed out in his most interesting paper in Darwin and Modern Science. Cambridge, 1909.

3

Obituary Notice of C. Darwin, Proc. R. Soc. vol. 44. Reprinted in Huxley's Collected Essays. See also Life and Letters of C. Darwin, ii. p. 179.

4

See the extracts in the Life and Letters, ii. p. 5.

5

Life and Letters, i. p. 82.

6

Obituary Notice, loc. cit.

7

Darwin and Modern Science.

8

Huxley, Obituary, p. xi.

9

In this citation the italics are mine.

10

Journal of Researches, Ed. 1860, p. 394.

11

F. Darwin’s Life of Charles Darwin (in one volume), 1892, p. 166.

12

Life and Letters, i. p. 83.

13

Life and Letters, ii. p. 8.

14

Avestruz Petise, i. e. Rhea Darwini.

15

A bird.

16

Life and Letters, i. p. 84.

17

It contains as a fact 231 pp. It is a strongly bound folio, interleaved with blank pages, as though for notes and additions. His own MS. from which it was copied contains 189 pp.

18

Life and Letters, ii. p. 116.

19

Life and Letters, ii. p. 10.

20

Life and Letters, ii. p. 146.

21

J. Linn. Soc. Zool. iii. p. 45.

22

It is evident that Parts and Chapters were to some extent interchangeable in the author’s mind, for p. 1 (of the MS. we have been discussing) is headed in ink Chapter I, and afterwards altered in pencil to Part I.

23