Species (philosophy)

“ Besides, it is an established fact, confirmed by all our observations stretching over thousands of years, that the characteristics of species are preserved in spite of all individual modifications, and that this preservation of the characteristics of species has its cause essentially in the free crossing of individuals. ”

“ If it could be proved that any part of the structure of any one species had been formed for the exclusive good of another species, it would annihilate my theory, for such could not have been produced through natural selection. ”

“ By dignity of species I mean those whose nature is permanent, invariable, and not subject to degradation. In those animals to which this singular advantage belongs, the characteristics are so strongly marked, that they cannot be mistaken nor confounded with any other species. In man, the noblest being of the creation, the species is sole and entire, because all the individuals of it, of whatever race, climate, or complexion, may intermix and produce together; and because it cannot be said that any animal approaches to man in any natural degree. ”

“ But animals or plants which thus differ in a state of nature are always classed as distinct species, and thus we see how, by the continuous survival of the fittest or the preservation of favoured races in the struggle for life, new species may be originated. ”

“ Not only must this connection of lives with lives be shown, but the theory must be able to show how it has come about that there are now distinct species of animals which never reproduce any type but their own. ”

“ In a former discussion, I have asked for facts which show, aside from the theory, that any one species of animal, distinctly marked as a continuing type, is connected by intermediate types or forms with any pre-existing race of another character. ”

“ But further light may be thrown on the subject, by a careful analysis of the facts which can be collected relative to the nature and origination of varieties; and it may be satisfactory to my readers to survey this field of enquiry.”
Granting, then, the truth of the limitation of species to be established, and taking as the definition of species the power of continual propagation, we have it proved at the commencement of the work, that “all human races are of one species;” ”

“ We are not bound to believe that all groups of individual animals, which naturalists may call species, have been separate products of creation. Man himself has by some naturalists been divided into several species; but we may well be content to believe the creation of one primitive form, and the production of existing races by variation. ”

“ Whatever may be said of the existence in nature, of other groups, there can be no question that species have the most definite existence, and it would seem then that nothing more need be proved for the theory of descent as opposed to the theory of special creation, than the establishment of the fact that species assume the characters of new species, or disappear altogether with a change of surroundings. ”

“ It is at the points of destination that the true species digress, and when these points [pg 103] are reached, the specific development ceases, and there remains only the possibility of the variety, the origin of which is conditioned by the multiplicity of individuals; but which must never be confounded with a true species. Every species represents an act of the will, a thought, and this thought cannot be shaken from its course, however close temptation may often come. ”

“ But it is the object of the present paper to show that this assumption is altogether false, that there is a general principle in nature which will cause many varieties to survive the parent species, and to give rise to successive variations departing further and further from the original type, and which also produces, in domesticated animals, the tendency of varieties to return to the parent form.
The life of wild animals is a struggle for existence. ”

“ If, in a state of nature, you find any two groups of living beings, which are separated one from the other by some constantly-recurring characteristic, I don't care how slight and trivial, so long as it is defined and constant, and does not depend on sexual peculiarities, then all naturalists agree in calling them two species ”

“ And, therefore, those who adopt the notion of the special creation of species do, it is said, in truth impair the professed character of the power to which they assume that the phenomena of the existence of species are to be referred, whereas the hypothesis of the evolution of species out of other species is much more consistent with the professed conception of the ultimate power. ”

“ If we turn to external nature, we behold endless diversity. How various the forms of animal life, whether considered in existing species, or traced back through endless ages to the first dawn of time! ”

“ Everywhere we may perceive that Nature secures her ends, and makes her distinctions on the whole manifest and real but everywhere without abrupt breaks We need not wonder therefore that gradations between species and varieties should occur; the more so, since genera, tribes, and other groups into which the naturalist collocates species, are far from being always absolutely limited in Nature, though they are necessarily represented to be so in systems. ”

“ If this is so, how much more remote must be the possibility, by any selection, or by any crossing to which Nature will allow the different animals to submit, to produce an animal of so distinct a type that it would amount to a different species from its known progenitors! ”

“ Those forms which possess in some considerable degree the character of species, but which are so closely similar to some other forms, or are so closely linked to them by intermediate gradations, that naturalists do not like to rank them as distinct species, are in several respects the most important for us. We have every reason to believe that many of these doubtful and closely-allied forms have permanently retained their characters in their own country for a long time; for as long, as far as we know, as have good and true species. ”

“ It is no wonder that a man who calls identical forms, when found in two countries, distinct species, cannot find variation in nature. Again, how unreasonable to suppose that domestic varieties selected by man for his own fancy should resemble natural varieties or species. ”

“ The fundamental idea of species, we would still maintain, is that of a chain of which genetically-connected individuals are the links. That, in the practical recognition of species, the essential characteristic has to be inferred, is no great objection—the general fact that like engenders like being an induction from a vast number of instances, and the only assumption being that of the uniformity of Nature. ”

“ But the mere existence of individual variability and of some few well-marked varieties, though necessary as the foundation for the work, helps us but little in understanding how species arise in nature. How have all those exquisite adaptations of one part of the organisation to another part, and to the conditions of life and of one organic being to another being, been perfected? We see these beautiful co-adaptations most plainly in the woodpecker and the mistletoe; and only a little less plainly in the humblest parasite which clings to the hairs of a quadruped or feathers of a bird ”

“ All those who have much to do with the study of natural history know that naturalists at the present day are extremely embarrassed in defining what they mean by the word species.
“In truth, observation for a long time has shown us, and shows us still in a great number of cases, collections of individuals which resemble each other so much in their organization and by the ensemble of their parts that we do not hesitate to regard these collections of similar individuals as constituting so many species. ”

“ At the dawn of modern biology, a century ago, no scientific evidence respecting the real history of life on the globe was extant, and, for any proof that existed to the contrary, species might have been of eternal duration. But philosophical speculation combined with theological dogma not only to favor the contrary opinion, but to lead the most philosophic naturalist of his day to embody the hypothesis of creation in a definition of species. ”

“ How can we deal with such a large subject in a brief way? It seems best to confine our attention in this chapter to an attempt to answer the question, What is a species? and are "species" natural groups clearly delimited by nature? ”

“ Whoever undertakes to proceed further in this argument, and endeavours to fix a general criterion of beauty respecting different species, or to show why one species is more beautiful than another, it will be required from him first to prove that one species is really more beautiful than another. ”

“ You will observe that, at present, I say nothing about species; I wish to confine myself to the consideration of the production of those natural races which everybody admits to exist. The question is, whether in nature there are causes competent to produce races, just in the same way as man is able to produce, by selection, such races of animals as we have already noticed.
When a variety has arisen, the Conditions of Existence are such as to exercise an influence which is exactly comparable to that of artificial selection. ”

“ Those who do not admit the principle of evolution, must look at species as separate creations, or in some manner as distinct entities; and they must decide what forms of man they will consider as species by the analogy of the method commonly pursued in ranking other organic beings as species. ”

“ On the ordinary view of each species having been independently created, why should the specific characters, or those by which the species of the same genus differ from each other, be more variable than the generic characters in which they all agree? ”

“ Some few naturalists maintain that animals never present varieties; but then these same naturalists rank the slightest difference as of specific value; and when the same identical form is met with in two distant countries, or in two geological formations, they believe that two distinct species are hidden under the same dress. The term species thus comes to be a mere useless abstraction, implying and assuming a separate act of creation. ”

“ It is by no means difficult to believe that varieties are incipient or possible species, when we see what trouble naturalists, especially botanists, have to distinguish between them—one regarding as a true species what another regards as a variety; when the progress of knowledge continually increases, rather than diminishes, the number of doubtful instances; and when there is less agreement than ever among naturalists as to what is the basis in Nature upon which our idea of species reposes, or how the word is to be defined. ”

“ I assume that such character has been, and is, indelible and immutable; that the characters which distinguish species from species now, were as definite at the first instant of their creation as now, and are as distinct now as they were then. If any choose to maintain, as many do, that species were gradually brought to their present maturity from humbler forms,—whether by the force of appetency in individuals, or by progressive development in generations—he is welcome to his hypothesis, but I have nothing to do with it. ”

“ Now all naturalists have learnt by dearly bought experience, how rash it is to attempt to define species by the aid of inconstant characters.
But the most weighty of all the arguments against treating the races of man as distinct species, is that they graduate into each other, independently in many cases, as far as we can judge, of their having intercrossed. ”

“ The facts of variability, of the struggle for existence, of adaptation to conditions, were notorious enough; but none of us had suspected that the road to the heart of the species problem lay through them, until Darwin and Wallace dispelled the darkness, and the beacon-fire of the 'Origin' guided the benighted. ”

“ In fact, zoologists and botanists are not only more at a loss than ever how to define a species, but even to determine whether it has any real existence in nature, or is a mere abstraction of the human intellect, some contending that it is constant within certain narrow and impassable limits of variability, others that it is capable of indefinite and endless modification. ”

“ He will soon convince himself that Species have no more definite and real existence in Nature than all the other divisions of the Animal Kingdom, and that every animal is the representative of its Branch, Class, Order, Family, and Genus as much as of its Species, Specific characters are only those determining size, proportion, color, habits, and relations to surrounding circumstances and external objects. ”

“ Whatever struggle for existence the individuals of this type have had to undergo, whatever modifications of structure or habits of life the survival of the fittest individuals of this type may have produced from the earliest imaginable period until the present time, the fact remains that this species of animal is a completed and final product. At the same time we have another completed and final type of animal known as man, which, so long as he has been known at all, is a distinct and peculiar species. ”

“ The same thing happens in the case of animals which circumstances have forced to change in climate, mode of life, and habits; but in their case the influences of the causes which I have just cited need still more time than the plants to bring about notable changes in the individuals.
“The idea of embracing, under the name of species, a collection of like individuals which are perpetuated by generation, and which have remained the same as long as nature has endured, implies the necessity that the individuals of one and the same species should not cross with individuals of a different species. ”