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Show 16 DARWINIAN A. In the first place, they practically agree in upsetting, each in its own way, the generally-received definition of species, and in sweeping away the ground of their objective existence in Nature. The orthodox conception of species is that of lineal descent: all the descendants of a common parent, and no other, constitute a. species; they have a certain identity because of their descent, by which they are supposed to be recognizable. So naturalists had a distinct idea of what they meant by the term species, and a practical rule., which was hardly the less useful because difficult to apply in many cases, and because its application was indirect: that is, the community of origin had to be inferred from the likeness; such degree of similarity, and such only, being held to be conspecific as could be shown or rea~onably inferred to be compatible with a common ongm. And the usual concurrence of the whole body of naturalists (having the same data before them) as to what forms are species attests the value of the rule, and also indicates some real foundation for it in Nature. But i£ species were created in numberless individuals over broad spaces of territory, these individuals are connected only in idea, and species differ from varieties on the one hand, and from genera, tribes, etc., on the ·other, only in degree; and no obvious natural reason remains for fixing upon this or that degree as specific, at least no natural standard, by which the opinions of different naturalists may be correlated. Species upon this view are enduring, but subjective and ideal. Any three or more of the human races, for example, are species or not species, according to the bent of th~ naturalist's mind. Darwin's THE ORIGIN OF SPECIES. 17 theory brings us the other way to the same result. In his view, not only all the individuals of a species are descendants of a common parent, but of all the related species also. Affinity, relationship, aU the terms which naturalists use figuratively to express an underived, unexplained resemblance among species, have a literal meanin~ upon Darwin's system, which they 1ittle suspected, namely, that of inheritance. Varieties are the latest offshoots of the genealogical tree in " an unlineal " order ; species, those of an earlier date, but of no definite distinction ; genera, more ancient species, and so on. The human races, upon this view, likewise may or may not be species according to the notions of each naturalist as to what differences are specific; but, if not species already, those races . that last long enough are sure to become so. It is only a question of time. How well the simile of a genealogical tree illustrates the main ideas of Darwin's theory the following extract from the summary of the fourth chapter shows : "It is a truly wonderful fact-the wonder of which we are apt to overlook from familiarity-that all an.imo.ls and all plants· throughout all time and space should be related to each other in group subordinate to group, in the manner which we everywhere behold-namely, varieties of the same species most closely related together, species of the same genus less closely and unequally related together, forming sections and sub-genera, species of distinct genera much less closely related, and genera related in different degrees, forming sub-families, families, orders, sub-classes, and classes. The several subordinate groups in any class cannot be ranked in a single :file, but seem rather to be clustered round points, and these round other points, and so on in almost endless cycles. On the view that each species has been independentlJ created, I can see no explanation of this |