Pleasant Ways in Science

by Richard A. Proctor

How, then, according to the Darwinian theory, is man related to the monkey? The answer to this question is simply that the relationship is the same in kind, though not the same in degree, as that by which the most perfect Caucasian race is related to the lowest race of Australian, or Papuan, or Bosjesman savages. No one supposes that one of these races of savages could by any process of evolution, however long-continued, be developed into a race resembling the Caucasian in bodily and mental attributes. Nor does any one suppose that the savage progenitor of the Caucasian races was identical with, or even closely resembled, any existing race of savages. Yet we recognize in the lowest forms of savage man our blood relations. In other words, it is generally believed that if our genealogy, and that of any existing race of savages, could be traced back through all its reticulations, we should at length reach a race whose blood we share with that race. It is also generally believed (though for my own part I think the logical consequences of the principle underlying all theories of evolution is in reality opposed to the belief) that, by tracing the genealogical reticulations still further back, we should at length arrive at a single race from which all the present races of man and no other animals have descended. The Darwinian faith with respect to men and monkeys is precisely analogous. It is believed that the genealogy of every existent race of monkeys, if traced back, would lead us to a race whose blood we share with that race of monkeys; and—which is at once a wider and a more precise proposition—that, as Darwin puts it, “the two main divisions of the Simiadæ, namely, the catarhine and platyrhine monkeys, with their sub-groups, have all proceeded from some one extremely ancient progenitor.” This proposition is manifestly wider. I call it also more precise, because it implies, and is evidently intended by Darwin to signify, that from that extremely ancient progenitor no race outside the two great orders of Simiadæ have even partially descended, though other races share with the Simiadæ descent from some still more remote race of progenitors.

This latter point, however, is not related specially to the common errors respecting the Darwinian theory which I have indicated above, except in so far as it is a detail of the actual Darwinian theory. I would, in passing, point out that, like the detail referred to in connection with the relationship of the various races of man, this one is not logically deducible from the theory of evolution. In fact, I have sometimes thought that the principal difficulties of that theory arise from this unnecessary and not logically sound doctrine. I pointed out, rather more than three years ago, in an article “On some of our Blood Relations,” in a weekly scientific journal, that the analogy between the descent of races and the descent of individual members of any race, requires us rather to believe that the remote progenitor of the human race and the Simiadæ has had its share—though a less share—in the generation of other races related to these in more or less remote degrees. I may perhaps most conveniently present the considerations on which I based this conclusion, by means of a somewhat familiar illustration:—

Let us take two persons, brother and sister (whom let us call the pair A), as analogues of the human race. Then these two have four great-grandparents on the father’s side, and four on the mother’s side. All these may be regarded as equally related to the pair A. Now, let us suppose that the descendants of the four families of great-grandparents intermarry, no marriages being in any case made outside these families, and that the descendants in the same generation as the pair A are regarded as corresponding to the entire order of the Simiadæ, the pair A representing, as already agreed, the race of man, and all families outside the descendants of the four great-grandparental families corresponding to orders of animals more distantly related than the Simiadæ to man. Then we have what corresponds (so far as our illustration is concerned) to Darwin’s views respecting man and the Simiadæ, and animals lower in the scale of life. The first cousins of the pair A may be taken as representing the anthropoid apes; the second cousins as representing the lemurs or half-apes; the third cousins as representing the platyrhine or American apes. The entire family—including the pair A, representing man—is descended also, in accordance with the Darwinian view, from a single family of progenitors, no outside families sharing descent, though all share blood, with that family.

But manifestly, this is an entirely artificial and improbable arrangement in the case of families. The eight grandparents might be so removed in circumstances from surrounding families—so much superior to them, let us say—that neither they nor any of their descendants would intermarry with these inferior families: and thus none of their great-grandchildren would share descent from some other stock contemporary with the great-grandparents; or—which is the same thing, but seen in another light—none of the contemporaries of the great-grandchildren would share descent from the eight grandparents. But so complete a separation of the family from surrounding families would be altogether exceptional and unlikely. For, even assuming the eight families to be originally very markedly distinguished from all surrounding families, yet families rise and fall, marry unequally, and within the range of a few generations a wide disparity of blood and condition appears among the descendants of any group of families. So that, in point of fact, the relations assumed to subsist between man, the Simiadæ, and lower animal forms, corresponds to an unusual and improbable set of relations among families of several persons. Either, then, the relations of families must be regarded as not truly analogous to the relations of races, which no evolutionist would assert, or else we must adopt a somewhat different view of the relationship between man, the Simiadæ, and inferior animals.

One other illustration may serve not only to make my argument clearer, but also, by presenting an actual case, to enforce the conclusion to which it points.

We know that the various races of man are related together more or less closely, that some are purer than others, and that one or two claim almost absolute purity. Now, if we take one of these last, as, for instance, the Jewish race, and trace the race backwards to its origin, we find it, according to tradition, carried back to twelve families, the twelve sons of Jacob and their respective wives. (We cannot go further back because the wives of Jacob’s sons must be taken into account, and they were not descended from Abraham or Isaac and their wives only,—in fact, could not have been.) If the descendants of those twelve families had never intermarried with outside families in such sort that the descendants of such mixed families came to be regarded as true Hebrews, we should have in the Hebrews a race corresponding to the Simiadæ as regarded by Darwin, i.e., a race entirely descended from one set of families, and so constituting, in fact, a single family. But we know that, despite the objections entertained by the Hebrews against the intermixture of their race with other races, this did not happen. Not only did many of those regarded as true Hebrews share descent from nations outside their own, but many of those regarded as truly belonging to nations outside the Jewish race shared descent from the twelve sons of Jacob.

The case corresponding, then, to that of the purest of all human races, and the case therefore most favourable to the view presented by Darwin (though very far from essential to the Darwinian theory), is simply this, that, in the first place, many animals regarded as truly Simiadæ share descent from animals outside that family which Darwin regards as the ape progenitor of man; and, in the second place, many animals regarded as outside the Simiadæ share descent from that ape-like progenitor. This involves the important inference that the ape-like progenitor of man was not so markedly differentiated from other families of animals then existing, that fertile intercourse was impossible. A little consideration will show that this inference accords well with, if it might not almost have been directly deduced from, the Darwinian doctrine that all orders of mammals were, in turn, descended from a still more remote progenitor race. The same considerations may manifestly be applied also to that more remote race, to the still more remote race from which all the vertebrates have descended, and so on to the source itself from which all forms of living creatures are supposed to have descended. A difficulty meets us at that remotest end of the chain analogous to the difficulty of understanding how life began at all; but we should profit little by extending the inquiry to these difficulties, which remain, and are likely long to remain, insuperable.

So far, however, are the considerations above urged from introducing any new or insuperable objection to the Darwinian theory, that, rightly understood, they indicate the true answer to an objection which has been urged by Mivart and others against the belief that man has descended from some ape-like progenitor.

Mivart shows that no existing ape or monkey approaches man more nearly in all respects than other races, but that one resembles man more closely in some respects, another in others, a third in yet others, and so forth. “The ear lobule of the gorilla makes him our cousin,” he says, “but his tongue is eloquent in his own dispraise.” If the “bridging convolutions of the orang[’s brain] go to sustain his claim to supremacy, they also go far to sustain a similar claim on the part of the long-tailed thumbless spider-monkeys. If the obliquely ridged teeth of Simia and Troglodytes (the chimpanzee) point to community of origin, how can we deny a similar community of origin, as thus estimated, to the howling monkeys and galagos? The liver of the gibbons proclaims them almost human; that of the gorilla declares him comparatively brutal. The lower American apes meet us with what seems the ‘front of Jove himself,’ compared with the gigantic but low-browed denizens of tropical Western Africa.”

He concludes that the existence of these wide-spread signs of affinity and the associated signs of divergence, disprove the theory that the structural characters existing in the human frame have had their origin in the influence of inheritance and “natural selection.” “In the words of the illustrious Dutch naturalists, Messrs. Schroeder, Van der Kolk and Vrolik,” he says, “the lines of affinity existing between different Primates construct rather a network than a ladder. It is indeed a tangled web, the meshes of which no naturalist has as yet unravelled by the aid of natural selection. Nay, more, these complex affinities form such a net for the use of the teleological retiarius as it will be difficult for his Lucretian antagonist to evade, even with the countless turns and doublings of Darwinian evolutions.”