of life; and we can clearly
understand on this view the meaning of rudimentary organs. But disuse and selection will generally act on each creature, when it has come to maturity and has to play its full part in the struggle for existence, and will thus have little power of acting
on an organ during early life; hence the organ will not be much
reduced or rendered rudimentary at this early age. The calf, for instance, has inherited teeth, which never cut through the gums of the upper jaw, from an early progenitor having well-developed teeth; and we may believe, that the teeth in the mature animal were reduced, during successive generations,
by disuse
or by
the tongue and palate
having been better fitted by having been better fitted by 1860 |
having been fitted by 1859 |
or lips, having become better fitted by 1861 1866 1869 |
or lips, having become excellently fitted through 1872 |
natural selection to browse without their aid; whereas in the calf, the teeth have been left untouched by selection or disuse,
and on the principle of inheritance at corresponding ages have been inherited from a remote period to the present day. On the view of each organic
being and each separate organ
having been specially created, how utterly inexplicable
it is
that parts, like
the teeth in the embryonic calf or like
the shrivelled wings under the soldered wing-covers of some
beetles, should thus
so frequently
bear the plain stamp of inutility! bear the plain stamp of inutility! 1860 1861 1866 |
bear the plain stamp of inutility! Nature may be said to have taken pains to reveal, by rudimentary organs and by homologous structures, her scheme of modification, which it seems that we wilfully will not understand. 1859 |
occur. 1869 1872 |
Nature may be said to have taken pains to reveal,
by rudimentary organs and by homologous structures,
her scheme of modification, which it seems that we wilfully will not understand.
|
I have now recapitulated the chief
facts and considerations which have thoroughly convinced me that species have
been modified, during a long course of descent, by the preservation or the natural selection of many successive slight favourable variations. been modified, during a long course of descent, by the preservation or the natural selection of many successive slight favourable variations. 1860 1861 1866 |
changed, and are still slowly changing by the preservation and accumulation of successive slight favourable variations. 1859 |
been modified, during a long course of descent, chiefly through the natural selection of numerous successive, slight, favourable variations. 1869 |
been modified, during a long course of descent. 1872 |
↑8 blocks not present in 1859 1860 1861 1866 1869; present in 1872 | This has been effected chiefly through the natural selection of numerous successive, slight, favourable variations; aided in an important manner by the inherited effects of the use and disuse of parts; and in an unimportant manner, that is in relation to adaptive structures, whether past or present, by the direct action of external conditions, and by variations which seem to us in our ignorance to arise spontaneously.
It appears that I formerly underrated the frequency and value of these latter forms of variation, as leading to permanent modifications of structure independently of natural selection.
But as my conclusions have lately been much misrepresented, and it has been stated that I attribute the modification of species exclusively to natural selection, I may be permitted to remark that in the first edition of this work, and subsequently, I placed in a most conspicuous position— namely, at the close of the Introduction— the following words: "
I am convinced that natural selection has been the main but not the exclusive means of modification." This has been of no avail.
Great is the power of steady misrepresentation; but the history of science shows that fortunately this power does not long endure.
It can hardly be supposed that a false theory would explain, in so satisfactory a manner as does the theory of natural selection, the several large classes of facts above specified.
It has recently been objected that this is an unsafe method of arguing; but it is a method used in judging of the common events of life, and has often been used by the greatest natural philosophers.
The undulatory theory of light has thus been arrived at; and the belief in the revolution of the earth on its own axis was until lately supported by hardly any direct evidence.
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I cannot believe that a false theory would explain, as it seems to me that the theory of natural selection does explain, the several large classes of facts above specified. ↑3 blocks not present in 1859 1860; present in 1861 1866 1869 1872 | It is no valid objection that science as yet throws no light on the far higher problem of the essence or origin of life.
Who can explain what is the essence of the attraction of gravity?
No one now objects to following out the results consequent on this unknown element of attraction;
notwithstanding that Leibnitz formerly accused Newton of introducing "occult qualities and miracles into philosophy." |
I see no good reason why the views given in this volume should shock the religious feelings of any one. ↑1 blocks not present in 1859 1860; present in 1861 1866 1869 1872 | It is satisfactory, as showing how transient such impressions are, to remember that the greatest discovery ever made by man, namely, the law of the attraction of gravity, was also attacked by Leibnitz, "as subversive of natural
and inferentially of revealed
religion."
|
A celebrated author and divine has written to me that "he has gradually learnt to see that it is just as noble a conception of the Deity to believe that He created a few original forms capable of self-development into other and needful forms, as to believe that He required a fresh act of creation to supply the voids caused by the action of His laws."
Why, it may be asked, have
all
the most eminent living naturalists and geologists rejected this view of
the mutability of species? It cannot be
|