By Justin E. H. Smith
Contemporary evolutionary biology tells us that there are five distinct
evolutionary lines in which bipedalism has emerged independently,
including, among other species, lizards (see R. C. Snyder, "Adaptations
for Bipedal Locomotion in Lizards," American Zoologist 2
(1962): 191-203); kangaroos (see M. B. Bennett, "Unifying Principles in
Terrestrial Locomotion: Where do Hopping Australian Marsupials Fit In?"
Physiological and Biochemical Zoology 73, 6 (2000): 726-735);
and, obviously, birds. Yet the perception persists that these other
species are not really bipedal, but only balance on their hind legs for
long periods, and that moreover they cannot be bipedal, since as we all
know the ability to walk on two legs is peculiar to humans.
As Craig Stanford writes in his popular book, Upright: The Evolutionary Key to Becoming Human: "Kangaroos and birds such as ostriches and penguins are bipedal -- sort of. But they are built on an entirely different body plan and are not, strictly speaking, reliant only on their legs for transport. Even if we throw in all the extinct forms of terrestrial animal life, such as Tyrannosaurus rex and its kin, the percentage of bipeds is still remarkably small. And birds and dinosaurs differ markedly in their brand of upright posture," etc. (Houghton Mifflin, 2003, Preface).
Such popular resistance suggests that bipedalism functions something like language, even if it is not quite as contested, in the way human beings conceive themselves: an adaptive trait among others that is inflated to tremendous significance as a way of marking out human uniqueness.
But surely language truly is a unique feature of humans. Or is it? To cite just one recent treatment of the subject, Lesley Rogers and Gisela Kaplan give substantial evidence that numerous species of mammal do in fact make referential sounds deserving of the name 'language'. Studies of ground-dwelling mammals, they affirm, "including squirrels, suricats ..., marmots, and Diana monkeys, have confirmed that the ability to discriminate between different alarm calls that signal the presence of different predators exists in a variety of species and that such signals lead to predictable responses by the receivers" ("All Animals are Not Equal: The Interface between Scientific Knowledge and Legislation for Animal Rights," in Cass R. Sunstein and Martha C. Nussbaum (Eds.), Animal Rights: Current Debates and New Directions (Cambridge: Cambridge University Press, 2004)). The authors infer from these studies that "many other mammals, not in the primate order, possess referent signals in their vocal repertoires and may thus show at least rudiments of higher cognitive abilities."
Language and bipedalism have long served as the most promising criteria for marking out human distinctness among natural beings. It is noteworthy that in antiquity 'featherless biped', while tongue-in-cheek, was as a definition of 'man' the only available alternative to 'rational animal'. In the 17th century some, such as the philosopher Margaret Cavendish, explicitly identified language as dependent upon upright posture, while the anatomist Edward Tyson had to devote almost as much energy to arguing that chimpanzees can walk on their hind legs as to arguing that they cannot speak. Both doctrines reveal an incipient atheism and materialism, and Tyson was not radical enough to accept them both.
Tyson had a long career in comparative anatomy, and it is clear that he approached his subject with passion and wonder. He makes a telling debut with his study of the "Scent-Bags in Poll-Cats" in 1676. In 1682-83, Tyson performs a great number of dissections, most of which take place in front of members of the Royal Society and the results of which are subsequently published in the Philosophical Transactions. Noteworthy among these is the "Tajacu, seu Aper Mexicanus Moschiferus, or the Anatomy of the Mexico Musk-Hog," as well as the study of a porpoise, an American rattlesnake, and numerous species of worms and insects. This is followed by a roughly 15-year hiatus in which he appears to have been engaged primarily in medicine, only to return to comparative anatomy in 1698 with the "Carigueya, seu Marsupiale Americanum, or The Anatomy of an Opossum," followed by the Orang-Outang, sive Homo sylvestris, Or, the Anatomy of a Pygmie Compared with that of a Monkey, an Ape, and a Man a year later.
In his early anatomical frenzy, Tyson's approach seems prima facie to be to dissect any animal he can get his hands on. But further consideration seems to reveal more specific concerns. On the one hand, he is concerned to study species that produce unusual secretions, particularly odoriferous ones, but also venom. In the human being, Tyson discovers in 1693 the scent-producing gland in the penis responsible for the secretion of smegma, a part now honored by the name 'Tyson's gland'. On the other hand, he is interested in what Mary Douglas, in her study of the dietary prohibitions of Leviticus, would identify as borderline cases: taxonomically puzzling species such as marsupials and marine mammals, the species that cannot be easily accommodated in folk-taxonomical systems. In the Orang-Outang, Tyson tellingly expresses regret that he has never been able to procure a zoophyte -- a borderline creature par excellence.
Quadrupeds, generally speaking, have served in Western thought as the paradigm brute, and ape perambulation, as much as any other purported ability, has persistently threatened the neat categorization of them with the cows and horses. One way around this problem has been to identify all of their four limbs as 'hands': thus the taxonomic designation suggested by Tyson, 'quadrumanes'. Animals, then, are the things that go on all fours, whether on four feet as the cows, or four hands as the ape, but humans are the creatures that, uniquely, have two of each.
Another approach is to deny that being able to balance on one's hind limbs for extended periods is a true marker of bipedalism. Thus Pliny in his Natural History is able to describe the satyrus indicus as "an animal, a quadruped, in the tropical mountains of India, a most pernicious one; with a human figure, but with the feet of a goat; and with a body hairy all over." And Aristotle maintains in the Historia animalium that bipedalism in apes is just a flourish, that the creature's underlying nature is to go on all fours.
Tyson believes that the ape is capable of both sorts of motion, and tellingly notes that bipedalism reveals the ape's humanlikeness in more ways than one: "When it goes on all four, as a Quadruped," he writes, "it seems all hairy: When it goes erect, as a Biped, it appears before less hairy, and more like a Man." He presumes that the knuckle-walking he had observed in the infant chimpanzee had been a consequence of the weakness resulting from its debilitating illness, and that a healthy ape would naturally prefer to walk on its hind limbs.
Tyson (correctly) adduces evidence for ape bipedalism from the direction of the hair follicles on his specimen's limbs: "The tendency of the Hair of all the Body was downwards; but only from the Wrists to the Elbow 'twas upwards; so that at the Elbow the Hair of the Shoulder and the Arm ran contrary to one another. Now in Quadrupeds the Hair in the fore-limbs have usually the same Inclination downwards, and it being here different, it suggested an Argument to me, as if Nature did design it as a Biped."
But can they speak? This would be something more than a proprium quarto modo -- a property universally shared by the members of a species that nonetheless does not serve to constitute their essence. Tyson explicitly sees the view that apes are capable of language as atheistic, and as a 'romance of antiquity'. As Richard Serjeantson notes of the early modern period, "An unsuitable anatomy… was one of the principal reasons for denying animals the capacity for articulate speech. They were widely taken to lack the right equipment of palate, larynx, tongue, lips… For this reason… the miraculous constitution of the human speech organs served as a powerful proof in natural theology" ("The Passions and Animal Language, 1540-1700," Journal of the History of Ideas (2001)).
Tyson shares in the majority view of animal language in the early modern period, yet, as we shall see, his own account of ape anatomy in the region of the mouth and throat poses a serious explanatory problem for him. No one in the 17th century is on record as defending the view that animals were capable of the sort of rich and flexible, referential vocal utterances that we today attribute to a grasp of syntax in human beings. Much more common was the view that animals were equipped to communicate to one another whatever they might have the need to communicate within the context of their animal lives, whether by calls or by visual signals, and that there was no reason in principle to consider this sort of communication inferior to human speech. This latter view is associated with certain radical deniers of human uniqueness among creatures, such as Girolamo Rorario with his 16th-century treatise That Animals Make Better Use of Reason than Humans, as also with those figures who hoped to set the art of physiognomic divination on a proper scientific footing, such as Marin Cureau de la Chambre and John Bulwer.
Tyson for his part is very clearly worried about the particular physiological likeness of apes and humans in the region responsible, at least in humans, for the production of speech: "As to the Larynx in our Pygmie," he writes, "I found the whole Structure of this Part exactly as 'tis in Man ... And if there was any further advantage for the forming of Speech, I can't but think our Pygmie had it. But upon the best Enquiry, I was never informed, that it attempted any thing that way. Tho' Birds have been taught to imitate Humane Voice, and to pronounce Words and Sentences, yet Quadrupeds never; neither has this Quadru-manous Species of Animals, that so nearly approaches the Structure of Mankind, abating the Romances of Antiquity concerning them."
Here, then, Tyson explicitly accounts for all reported instances of teaching animals to speak as mere imitation, and not as indicative of any conscious activity. He goes on to write of the larynx that "Anaxagoras, Aristotle, and Galen have thought [it] to be the Organ which Nature has given to Man, as to the wisest of all Animals; for want perhaps of this Reflection: For the Ape is found provided by Nature of all those marvellous Organs of Speech with so much exactness ... that there is no reason to think, that Agents do perform such and such actions, because they are found with Organs proper thereunto; for, according to these Philosophers, Apes should speak, seeing that they have the Instruments necessary for Speech."
Well then, why aren't they speaking? Tyson repeats his conviction that the only explanation lies in the fact that anatomy is not, to borrow a phrase, destiny, that one cannot infer from the organs a creature has what it will be able to do: "From what is generally received, viz. That the Brain is reputed the more immediate Seat of the Soul it self; one would be apt to think, that since there is so great a disparity between the Soul of a Man, and a Brute, the Organ likewise in which 'tis placed should be very different too. Yet by comparing the Brain of our Pygmie with that of a Man; and with the greatest exactness, observing each Part in both; it was very surprising to me to find so great a resemblance of the one to the other, that nothing could be more ... Since therefore in all respects the Brain of our Pygmie does so exactly resemble a Man's, I might here make the same Reflection the Parisians did upon the Organs of Speech, That there is no reason to think, that Agents do perform such and such Actions, because they are found with Organs proper thereunto: for then our Pygmie might be really a Man."
But this is an odd sort of reasoning, particularly in view of the fact that, as concerns bipedalism, Tyson is perfectly willing to reason that the ape is capable of this simply in view of the fact that "'tis sufficiently provided in all respects to walk erect." Why does sufficient provision translate into a capability in the one case but not in the other?
By the late 18th century, we find Lord Monboddo offering a different account of Tyson's findings regarding the presence of speech organs in apes, but the absence of speech. For him, the great apes are "a barbarous nation, which has not yet learned the use of speech." He argues that since, as Tyson has shown, they possess the organs necessary to speak, what prevents them is only that they have never been educated, just as "men, living as the Orang Outangs do, upon the natural fruits of the earth, with few or no arts, are not in a situation that is proper for the invention of language." Among 17th-century writers, only Louis Le Comte employs a similar racist comparison between non-European people and apes, but even he continues to see speech as a marker of absolute distinctness separating all humans equally from all apes: he writes of apes that their "Shape, Stature, Countenance, Arms, Legs, and other Members of the Body, are so like ours, that excepting the Voice only, one should have much ado not to reckon them equally men with certain Barbarians in Africa, who do not much differ from Beasts."
One of the great ironies of early modern anthropology is that it is the religious and creationist world-view of the sort defended by Tyson, with its commitment to supernatural and permanent species reification, that spoke in favor of common origins for all of humanity with clear genealogical and essential criteria for discriminating the 'lowest' humans from apes. The opposition to such a reified view of species, already celebrated by Locke, is a part of the story of the emergence of modern scientific racism -- once humanity is no longer conceived as uniquely a reflection of God, then greater and lesser proximity to the ape becomes thinkable. For Lord Monboddo, the lower boundary of humanity may be crossed by a well-trained orangutan, and there is nothing about the people dwelling near the lower boundary that ensures their superiority to it. For Tyson, in contrast, the Cartesian criterion remains in place: there must be an absolute division between humans and animals; animal speech would threaten to collapse this divide; therefore, it is unthinkable.
We may speculate, though, that by opening the door to ape bipedalism, Tyson himself has set Western thought on that path that will lead to the dissolution of the neat ontological divide between humans and animals, and that will bring in its wake so much social havoc, and so much scientific progress, over the following 300 years.
If we wish to continue jealously guarding language as something uniquely our own, and to inflate it into some quasi-divine human virtue, we should ask ourselves whether this is any less small-minded than the ongoing effort, Craig Stanford its latest spokesman, to do something similar with bipedalism -- an impressive skill, to be sure, but far from godly. It is amazing to me that old pieties about the special place of humans in the cosmos can still sell books, even when the case can no longer be made on the basis of profound, theologically based convictions, and must instead rest on trivial features of our species such as gait and call. I suspect that there's some kind of dim self-congratulatory buzz coursing through electric eels too, some faint self-love rooted in the singularity of this species' special adaptive trait, which, unlike language and bipedalism, really is a rarity in nature.
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This essay was first published by 3QuarksDaily.
