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Show 424 DARWINISM CliAI'. that sheep and goats are specially mountain and rock-loving animals may be explained by their being a later modification, since the divided hoof once formed is evidently well adapted to secure a firm footing on rugged and precipitous ground, although it could hardly have been first developed in uch localities. Mr. Cope thus concludes: "Certain it is that the length of the bones in the feet of the ungulate orders has a direct relation to the dryness of the ground they inhabit, and the possibility of speed which their habit permits them or ncce~sa.rily impo cs on them." 1 If there is any truth in the explanation here briefly summarised, it mu t entirely depend on the fact of individn:tl modifications thus produced being hereditary, and we yeL await the proof of this. In the meantime it is clear that the very same re. nlts could h:we been brought about by variation and natural selection. For the toe , like <tll other organ , vary in size and proportion , and in their degr e of union or separation; and if in one group of ttnimals it was beneficial to have the middle toe larger and longer, and in another set to have the two middle toes of the same size, nothing can he more certain than that these particular modifications wonld be continuously preserved, and the very results we sec ul ti matcly produced. The oft-repeated objections that the cause of varia,tiom; i~-' unknown, that there mu. t be something to determine vari<ttion,; in the right direction ; that "natural selection include: 110 actively progressive principle, but must wait for the development of variation, and then, after securing the survival of the best, wait again for the best to project its own variations for selection," we have already sufficiently answered by showing that variation-in abundant or typical species- is <dwa.\ s present in ample amount; that it cxi ts in all p:u'ts an<l organs; that these vary, for the most part, independently, so that any required combination of variations can be secnrc<l; and finally, that all variation is necessarily either in excess or defect of the mean condition, and that, consequently, the right or favourable Yariations c.tre so fr quently present thaL tho unerring power of natural selection never wants materials to work upon. 1 O'rigin of the Fittest, p. 374. XIV FUNDAMENTAL PROBLEMS 425 S~tpposed Action of Anirnal Intelligence. The following passage briefly summarises Mr. 'ope's position: "Intelligence is a con ervative prin ·ipl , and will always direct effort and u c into line which will he beneficial to its possessor. H re we have the ource of the fitte t, i.r>. addition of parts by increase and loc:ttion of growth-force, directed by the influence of various kind. of compulsion in the lower, and intelligent opbon among higher animals. Thus intelligent choice, ta.king advantage of the successive evolution of physical conditions, may be regarded as the o?'iginato?· nj the fittest, while natural . 1 ction is the tribunal to which all result. of a.cccler:.tted growth arc ~nbmittcd. This preserves or de troys them, and lctcrminc the new points of departure on which accelerated growth ·ha.ll build." 1 Thi. notion of "intcllirrencc "-the intelligence of the animal itself-determining its own variation, is so evidently a very partial theory, inapplicable to the whole vegetable kingdom, and almost so to all the lower forms of animals, amongst which, nevertheless, there i. the very . amc adaptation and co-ordination of part and functions a: among the hio·he. t, that it is stranrre to see it put forward with uch confidence as necessary for the completion of arwin's theory. If "the various kinds of compulsion "-hy which are apparently meant the laws of variation, growth, and reproduction, the truggle for existence, and the actions necessary to pre. orvc life under the conditions of the animal's environment- arc :ufficient to have developed the varied forms of the lower animals and of plants, we can sec no r a.~on why the same "compulsion" should not have carried on the development of the hi o·hcr animals also. The action of this "intelligent option" is altogether unproved; while the acknowledgment that natnral selection is the tribunal which either pre erves or destroy the variations submitted to it, seem quite incon. istcnt with the statement that intelligent choice is the "orginator of the fittest," since whatever is really "the fittest" can never be destroyed by natural selection, which is hnt another name for the survival of the fittest. If "the fittest '' i always definitely l Origin of the Fittest, p. 40. |
