Variation

“ The great law of variation teaches—both in the general theory of evolution and in the smaller field of biology where it becomes the theory of descent—that the variety of phenomena flows from an original unity, the diversity of functions from a primitive identity, and the complexity of organization from a primordial simplicity. The conditions of existence for all individuals are, from their very birth, unequal. ”

“ What we have said before in regard to the overlapping of variations among different races and types, and the great range of variability in each type, may also be expressed by saying that the differences between different types of man are, on the whole, small as compared to the range of variation in each type. ”

“ But perhaps the most discouraging circumstance of all is, that in scarcely a single actual instance in nature can we assert whether an observed variation is useful or not—a drawback that I distinctly pointed out some time ago. ”

“ We have in this case a good example of nature's tendency to the perpetuation of a variation. Here it is certainly a variation which carried with it no use or benefit; and yet you see the tendency to perpetuation may be so strong, that, notwithstanding a great admixture of pure blood, the variety continues itself up to the third generation, which is largely marked with it. ”

“ In my work on the variation of domestic animals, I have attempted to arrange in a rude fashion the laws of variation under the following heads:—The direct and definite action of changed conditions, as exhibited by all or nearly all the individuals of the same species, varying in the same manner under the same circumstances. ”

“ How will the struggle for existence, briefly discussed in the last chapter, act in regard to variation? Can the principle of selection, which we have seen is so potent in the hands of man, apply under nature? ”

“ In most, perhaps in all cases, the organisation or constitution of the being which is acted on, is a much more important element than the nature of the changed conditions, in determining the nature of the variation. ”

“ It is impossible to form any opinion on these questions, without some preliminary acquaintance with the range of variation exhibited by human structure in general—a subject which has been but imperfectly studied, while even of what is known, my limits will necessarily allow me to give only a very imperfect sketch. ”

“ Although every variation is either directly or indirectly caused by some change in the surrounding conditions, we must never forget that the nature of the organisation which is acted on, is by far the more important factor in the result. ”

“ The Newton of biology, who will discover the laws of variation and heredity, has not, it is safe [Pg 63] to say, yet appeared. Variation in a definite direction in virtue of an internal tendency in the organism (Nägeli) ; variation in response to the specific stimulus of the environment (Eimer) ; variation due, at least in animals, to the conscious effort of the individual (Lamarck) ”

“ Which is the more entitled to support, even from their own professed stand-point, a theory which refers favorable variations to an innate tendency in organisms, or that which ascribes variations to reversion? No; as any other view would be incompatible with the success of their darling theory, they are perfectly content to consider variation as an ultimate law, even though such a consideration involves a gross inconsistency. ”

“ No two men are organized in all respects alike. There are individual variations in structure, both native and acquired. These may be too slight to be appreciable369 by any other test than the difference of reaction under similar external stimuli; but the variations in the sensibility to music, color, temperature, sexual influence, moral influence, etc., betray corresponding differences in the organisms. Any one variation in structure, seemingly trivial, may be the origin of well-marked diversity in physical and moral characters. ”

“ Do meaningless peculiarities, which we admit often arise as spontaneous variations, ever perpetuate themselves in all the individuals constituting a variety or race, without selection either human or natural? ”

“ Nor can we account in all cases for the appearance through bud-variation of new characters by the principle of reversion to long-lost characters. He who wishes to judge how far the conditions of life directly cause each particular variation ought to reflect well on the cases immediately to be given. ”

“ You see, it changes a little from the parent form or, as we say, varies. Every living thing has this power to vary within limits. No doubt, the power of variation was much greater in early times, and animals and plants were able to change much more then than now. ”

“ Variation supplies the raw material upon which Natural Selection is supposed to work. When we turn to examine the process by which its results should be produced, we find, quite apart from the above difficulties, a crop of others still more formidable. ”

“ We shall now see that this Organising Activity gives not only direction, but an upward direction to the whole which it controls.
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We have already noted that among individuals the variety is such that no two are exactly alike. Each individual, however nearly alike, varies in some slight degree from every other. And new variations are constantly being created. Now we have to note that besides variation there is gradation. There is a scale of being. And individuals are graded on that scale. One is higher than another. ”

“ If man can by patience select variations useful to him, why, under changing and complex conditions of life, should not variations useful to nature's living products often arise, and be preserved or selected? ”

“ Variations in form, size, color, and arrangement of parts have much less to do, and the uses, purposes, and functions of things and of their parts much more to do, with distinctness of character and meaning than we should be likely to think. ”

“ In this way we acquire an approximate conception of the possible mechanical modus operandi of actual events—namely, of the manner in which the useful variations required by the conditions of life can always, that is, very frequently, make their appearance. ”

“ Can it, then, be thought improbable, seeing that variations useful to man have undoubtedly occurred, that other variations useful in some way to each being in the great and complex battle of life, should sometimes occur in the course of thousands of generations? ”

“ Some of these variations appeal to man as being of practical value, others as beautiful, and others again as curious or interesting. He selects those individuals whose variations he wishes to preserve, breeding only them together, and in this way accentuates those variations he desires to perpetuate. ”

“ We are consequently reduced to a condition exactly parallel to that which we find, according to the theory of evolution, in biology.172 Variations are the result of a differentiation of some unit. It is the object, in the classification of biological data, to demonstrate, by means of a series of ascending forms, the evolution of the most highly differentiated from the least differentiated. ”

“ In other words, some attribute a positive influence to outer conditions, and say that they actually give rise to variations, while the others say these conditions have only a negative influence and merely eliminate variations. ”

“ Variations may be divided into two classes; those which appear to our ignorance to arise spontaneously, and those which are directly related to the surrounding conditions, so that all or nearly all the individuals of the same species are similarly modified. ”

“ But, in the second place, observation shows that slight variations are perpetually being introduced with every successive generation, and many of these variations are transmitted to the generations that follow. ”

“ It seems pretty clear that organic beings must be exposed during several generations to the new conditions of life to cause any appreciable amount of variation; and that when the organisation has once begun to vary, it generally continues to vary for many generations. ”

“ This preservation of favourable variations and the rejection of injurious variations, I call Natural Selection. ”

“ For the transformists, as is well known, variety, race, and species are not fixed concepts. “From variety to race, from race to species, there is a continuous insensible passage. Individual modifications, at first slight, give rise to a variety or to a race. ”

“ We see trees, houses, fields, living beings in our own shape, and in shapes more or less analogous to our own. These are perpetually changing the mode of their existence relatively to us. To express the varieties of these modes, we say, we move, they move; and as this motion is continual, though not uniform, we express our conception of the diversities of its course by—it has been, it is, it shall be. These diversities are events or objects, and are essential, considered relatively to human identity, for the existence of the human mind. ”

“ Both reason and experience seem to indicate to us that the infinite variety of nature, (and variety cannot exist without inferior parts, or apparent blemishes) is admirably adapted to further the high purpose of the creation, and to produce the greatest possible quantity of good. ”

“ This diversity, this difference is like the naturally created dissimilarity and variety of the limbs and organs of the human body, for each one contributeth to the beauty, efficiency and perfection of the whole. ”

“ When any shade of variety is wanting, some place in heaven may be said to be as yet vacant; so that all the differences, or varieties, are to be filled up before the form can exist in full perfection. ”

“ But since both the natural varieties of mankind, and the original diversities of local circumstances, are much less considerable than the points of agreement, there will naturally be a certain degree of uniformity in the progressive development of the species and of its works. ”

“ Shall we, then, conclude that these changes in the appearance of a single individual are for the sake of variety—as some would explain the great diversity of specific form and coloration among animals and plants? ”

“ But whatever means Nature adopts, her aim is always the same—to specialise, to differentiate, to produce diversity from uniformity.
Differentiation not only raises the level of organisation; it usually also takes the direction of adaptation to particular habits of life, and this is perhaps the most fruitful cause of diversity. ”

“ Let the people bring out their talents, and have the variety within them brought forth and made manifest so {650} that we can behold it, like the variety in the works of nature. See the variety God has created—no two trees alike, no two leaves, no two spears of grass alike. ”

“ Examine the designs before you, and you will discover the principal varieties exhibited in the human type. You have there individuals from all parts of the world; you see that they differ considerably in color, some in their hair, others in their size, or in their peculiar features. It behooves us to ascertain if the differences that present themselves in these human groups are those of species, or if they merely indicate the existence of races belonging to the same species. ”

“ I here assume, what is agreed on by most writers, that beauty of form—so far as it is independent of sensuous pleasure on the one hand, and pleasures of association and suggestion on the other, is resolvable into the presence of a certain order among manifold details, which order is commonly spoken of as unity in variety. With respect, first of all, to the way in which the element of variety and contrast presents itself in visible form, a word or two will suffice. ”

“ With all the variety that there is in the world of our experience, a variety appealing to our consciousness of difference, there is also great repetition, sameness, or unity. There are many shades of color, as distinguished by the discriminative sensibility of the eye ”