Adam's Tongue: How Humans Made Language, How Language Made Humans

by Bickerton, Derek

  They would kill the interlopers if they got half a chance.

  How could our ancestors have coped with the competition? They had no natural defenses against their competitors’ teeth and claws. They had no artifacts that by any stretch of the imagination you could call weapons. All they had—and that only potentially—was numbers.

  Nathan Bedford Forrest was the least educated but the most innovative of Civil War commanders; for instance, he was the first to realize that the best use for cavalry was not to charge around waving sabers but to get men with rifles into commanding positions as quickly as possible. His was the pithiest-ever advice for success in combat, whether against human enemies or carnivorous scavengers:

  “Git thar fust with the most men!”

  If only our ancestors could come up with sufficient numbers, they could hold off the competition by screaming and flinging stones while they butchered and consumed the carcass. But how would they gather those numbers? A general like Forrest could issue orders and ensure that his orders were obeyed. But how, without language, could you get the most to get there at all? And was there, in the whole course of evolution, any kind of precedent for that?

  We seem to have gone a long way from language, I hear you muttering.

  Don’t worry. In the next chapter, we’ll go further still.

  7

  GO TO THE ANT,

  THOU SLUGGARD

  Go to the ant, thou sluggard; consider her ways, and be wise.

  —Proverbs 6:6

  BEYOND VERTEBRATES

  Several years ago, the prestigious journal Science, which does not normally pay much attention to language, published an article coauthored by Marc Hauser, Noam Chomsky, and Tecumseh Fitch entitled “The Faculty of Language: What Is It, Who Has It, and How Did It Evolve?” The article was placed in that section of the journal named “Science’s Compass,” and it was indeed designed to give directions to us poor benighted folks who (unlike the authors of the article) had actually been laboring in the quagmire of language evolution studies for a number of years. In chapter 9 we’ll examine this article and I’ll show you why, far from being a road map for future research, it is in fact a pernicious piece of misdirection.

  However, the article did contain one useful piece of advice: “Current thinking in neuroscience, molecular biology, and developmental biology indicates that many aspects of neural and developmental function are highly conserved, encouraging the extension of the comparative method to all vertebrates (and perhaps beyond)” (my italics).

  Well, let me caveat that, as Alexander Haig might have said. The part that follows the last comma is what’s useful. The part that precedes it, what in the authors’ opinion makes it worthwhile for us to look for language origins beyond vertebrates, relates to what is known nowadays as “evo-devo,” the marriage of evolutionary and developmental biology. Evo-devo looks at the genes that turn a fertilized cell into a wasp or a mouse or a human and asks what our new and ever-growing understanding of genetic processes can tell us about how, out of such limited materials, so many varied life-forms evolved. One key insight of evodevo is that homology is much more widespread than we thought.

  In chapter 4 we looked at the difference between homology and analogy. Homology, you’ll recall, was when the same feature occurs in two species because it was shared by their common ancestor. Before evo-devo, people looked for homologies only among closely related species. It wouldn’t have occurred to anyone, for example, to choose the wings of birds and bats as examples of homology. To find the common ancestor of birds and bats you’d have to go back around 300 million years, and in both lines of descent you’d find innumerable intervening species that didn’t have wings. So wings just had to be analogies, the result of aerodynamic factors—how else would an animal get to fly around? And the genes that set up the two different pieces of equipment for flying just had to be different from one another—didn’t they?

  If you got that one wrong, you’re in good company. Ernst Mayr, doyen of twentieth-century evolutionary biology, wrote in 1963: “Much that has been learned about gene physiology makes it evident that the search for homologous genes is quite futile except in very close relatives. If there is only one efficient solution for a certain functional demand, very different gene complexes will come up with the same solution, no matter how different the pathway by which it is achieved. The saying ‘Many roads lead to Rome’ is as true in evolution as in daily affairs.”

  Since then we’ve learned an awful lot about genes and how they work. In particular we know that evolution, like any good home-workshop do-it-yourselfer, never throws stuff away. No matter how useless some bit of machinery looks, there’s no knowing when a use for it might come up. With a little ingenuity, you can reshape it and use it all over again—saves you going out and buying something. And in nature there’s no Home Depot to go to anyway.

  Thus many of the same genes are still there in bats and birds and those same genes regulate the development of the body parts that still underlie their superficially different wings—the arm bones and the bones of hand and finger that those same genes also developed in all the forelimbs of all the ancestors of bats and birds that didn’t happen to fly. That’s what’s called in the trade “deep homology.” In fact, deep homologies can go even deeper than that. To find a common ancestor for the mouse and the fly, you’d have to go back almost twice as far as the common ancestor of birds and bats. And yet the same set of genes determines the overall body plans of mice and flies.

  For there’s no simple one-to-one relationship between genes and body parts, in which the same genes stamp out identical, cookie-cutter, one-size-fits-all bits and pieces; genes can be differently expressed in different combinations and in different environments, giving rise to body plans that can look strikingly unalike until you see that the same basic proportions hold in each of them—back to front, side to side, inside to outside.

  Giraffes’ necks are many times longer than ours, but they have just the same number of bones—seven. Genes that govern bone length make bones longer or shorter, to fit the overall blueprint for whichever animal they’re building. But they can’t change the number of bones—that’s not their job, and it seems it isn’t any gene’s job, unless some strange mutation just happens to come along.

  There’s a big problem, though, in relating any of this to language (as I believe Noam Chomsky wants to do, in ways that are, as yet, far from apparent).

  You see, deep homology doesn’t shape behavior. It helps to shape body parts, no question of that, but I don’t think it’s ever been claimed that a particular behavior results from deep homology. And language is, after all, a form of behavior—behavior underpinned by genes, to be sure, but in no way controlled, determined, or mandated by them. Genes help to shape body parts (including brain parts, naturally), and body parts help to shape behavior, but there are just too many independent variables between genes and behavior for deep homology to help when it comes to looking for antecedents of particular behaviors—especially of a behavior that’s unique.

  So, for all the promise of evo-devo in other areas, it gives us no good reason to go looking for precursors of language in strange new places. If we’re to search outside the primates, even outside the vertebrates, it’s behavior, not genes, that we’ll be looking for. Because that’s what niche construction theory is telling us to do.

  New behaviors arise through the construction of niches, and it’s those niches that in turn determine how genes will express themselves. (It was, after all, the development of powered flight that eventually caused genes normally devoted to building front legs to express themselves, among birds and bats, in the form of wings.) Behaviors develop because the niche requires them and can’t be constructed without them. Species have a choice: stick to the old ways and maybe go extinct, or try branching out into something new. They may not succeed in this second course. They may simply lack a genome that can be tweaked into supporting the behaviors they’ll need—they’re variatio
n-limited, in Eörs Szathmáry’s phrase. But if they’re only selection-limited, they’ll respond to the selective factors inherent in the new niche by constructing new and niche-appropriate behaviors, and the feedback process between genes and behavior will kick in.

  Accordingly, we’re not looking for deep homologies, we’re looking for niche analogies: niches that share the same kinds of selective pressure. Since it’s the niche that matters, the niche that determines the animal’s behavior, it doesn’t matter how far we stray from our own species. Whatever kind of living organism we’re dealing with—reptile, mammal, fish, insect, bird—the same kind of niche will have similar consequences.

  Remember at the end of chapter 2 I suggested a selective pressure highly likely to lead toward language: the need to transmit information about food sources that lay beyond the sensory range of message recipients. So what we need to look for, in the vast array of species on earth, are ones that have niches requiring this kind of information exchange. If the information that’s transferred happens to concern food sources too large to be handled by individuals, calling for some kind of recruitment strategy, so much the better.

  Surprisingly enough, almost the only species that meet these criteria are ants and bees.

  AMONG THE HYMENOPTERA

  People have known about bee ACSs for a long time, ever since Karl von Frisch’s studies of honeybee communication half a century ago. It was known, even then, that the ACS of bees was capable of displacement. Recent research has more than confirmed von Frisch’s work, adding fascinating knowledge about how bees measure distance (they compare the speeds at which images of objects in the landscape appear to cross their retinas as they fly).

  But beyond the “Wow!” factor, people didn’t think bee displacement had anything to do with language. Bees were too far from us, phylogenetically speaking. And since behavior, like anything else, was seen as a monopoly of the genes, there couldn’t possibly be a connection. It wasn’t until niche construction theory came along that you could look at the situation in any other way. But when you did, the picture changed dramatically.

  So, let’s look at bees and how they behave and why.

  Bees are eusocial; in every community, only one female, the queen, and a handful of males, the drones, are fertile and can mate. This means that all other members of the community are sterile and are also siblings of one another. Since in addition they are haploid-diploid (the female parent has two copies of each chromosome in each cell, the male only one) bees share far more of their genes than most siblings do. Now recall the principle of inclusive fitness, meaning that animals will try to preserve not only their own genes but those same genes wherever they occur. Remember how, in the case of survival calls, animals risk their own lives to benefit close relatives who share their genes. So, just as you’d expect, there’s more cooperation and cohesion among bees than in almost any other species, until you get to humans.

  If the good of one is the good of all—and it is, for if they don’t store enough honey all the bees will die next winter—then it’s in the interests of everyone to share information about food sources. This is not so among many species. Members of most, on finding a tasty food source, keep it to themselves, and a few may even use phony warning calls to distract group members who try to take it. For bees, food sources are patches of flowering plants that bloom all at once and may not last more than a day or two. If a single bee locates such a source, it can’t hope to fully exploit that source. For the good of itself and all, it must recruit its nestmates to help it.

  Recruitment—that turns out to be the key word in the birth of language.

  The sites for which bees must recruit nestmates may lie several kilometers from the hive. A measurable period of time, several minutes at least, must elapse between when the bee locates the source and when it passes on the information. Therefore an effective bee ACS must displace—it must transmit information about states and events existing in a different place and at a different time. Unlike other ACSs, it cannot function if it remains imprisoned in the here and now. But in escaping the here and now, it is responding to the selective pressure noted at the end of the last section—the pressure likeliest to move in the direction of language.

  In order to recruit effectively, bees need to tell other bees where food sources are located and how far away those sources are. They show whether the food site is near or far by choosing between two kinds of dance. If the site is within say seventy-five yards of the hive, they dance in circles, so that’s called the “round dance.” If it’s farther, they dance in a series of elliptical loops, waggling their bodies as they come through the straightaway in the middle, so that’s called the “waggle dance.” The faster they dance, the farther away the site is. The axis on which they waggle does not, as you might suppose, point toward the food; dances take place on the vertical face of a honeycomb, and even if they were done on the level, by the time a bee got out of the hive it would have no idea which direction to go in. (Imagine yourself being pointed in a certain direction in a dark room in a windowless office block and then, after making your way through several halls and corridors and down a couple of staircases, trying to recalibrate that orientation in the daylight outside.)

  So the bees execute an amazing transformation based on the current position of the sun. They compute the angle between the sun’s current position and the site and convert that from horizontal to vertical, representing the sun’s position by a vertical axis and the angle between sun and site by the angle between the vertical and the axis of the waggle dance. If this sounds easy (and I don’t think it does, do you?) go to a south-facing window, pick an object, estimate its angle from the sun, and then take a pencil (not indelible!) and mark that same angle as a variance from the vertical on the nearest wall. (No mechanical aids, not even your fingers—that’s cheating! Bees do it all in their heads.) Then think: a bee’s brain is pinhead-sized compared to yours.

  But I thought, you complain. The bee didn’t. It just used instinct.

  There you go with that homocentric prolearning bias again. Now tell me how you produced the sentence you just spoke. That was an unconscious mental computation, and so was the bee’s reading of her buddy’s waggle dance. Both are just cases of subconscious thought.

  Did the first-ever bee get born with that instinct? The first bee wasn’t even social; it was every bee for itself, back then. At some time in the past, bees somewhere must have constructed the eusocial niche, and must later on have started, in some doubtless highly clumsy and inefficient way, the practice of informing their fellows where to go for food. So they got it wrong most of the time? Of course, but with just a few successes some bee colonies survived the winter while others went under. The survivors got better at it as the feedback mechanisms of niche construction kicked in, the niche shaping how the genes were expressed (and selecting rare beneficial mutations as these came along) and the expression of the genes shaping the niche, until, probably millions of years ago, you reached the spot-on computations of modern bees.

  So honeybees are the obvious model for a system of communication that involves displacement. But it doesn’t follow that they’re the best model. True, they’re extractive foragers, just like our ancestors were. But bees forage in the air; our ancestors foraged on land. Bees forage in one place only, inside flowers, for two things only, the nectar and pollen those flowers contain; our ancestors foraged in many different kinds of places, for many different kinds of food. They may have preferred the meat of large mammals, but that was a chancy and unpredictable business. Between bonanzas they had to go the omnivorous route of their ancestors, the australopithecines.

  In their foraging, our ancestors were less like bees than like ants.

  ANTS ’R’ US?

  Ants have always fascinated us. Traditionally, they are held up as models of frugality and industry. Aesop’s fable contrasts the responsible ant with the irresponsible grasshopper, fiddling all summer, starving when winter comes. The epigraph to th
is chapter is but one of a number of references to ants in the Bible, the Koran, and other religious texts. And at the end of this book we’ll note some eerie parallels between ants and humans, suggesting one far-from-inconceivable human future that most of us would rather not conceive.

  For now, however, their communication is our sole focus.

  Like bees, ants are extractive foragers; working from a central place, the nest, they radiate out over relatively large areas. Their diet varies from species to species, but many species will eat almost any organic matter that doesn’t move, and quite a bit that does, if it’s not too big and lively for them. They will eat other insects, other ants, dead caterpillars, overripe fruit, you name it. They’re sweetaholics, as you know if you’ve ever spilled sugar in the kitchen, but they love protein too. A lot of the things they love are much bigger than they are.

  Ants, again just like bees, are eusocial. Beyond that, since there are more than eleven thousand known species of them, it’s hard to generalize. Some save food for the winter, just like Aesop’s did, and some don’t. Some make war on the nests of other species; most don’t. Some herd, some farm, some forage, just like humans over the last few thousand years. But all of them communicate chemically.

  Ants produce, from their tiny bodies, a stunning range of chemical substances, some of which our own chemists have not yet replicated. For instance, one species of ant that conquers other colonies and enslaves their inhabitants (sound familiar?) can release a chemical that causes ants of the colony they’re attacking to fight one another. (I’ve dreamed of creating a human equivalent, to be produced under the trademark “Fight!” What’s deterred me—apart from ignorance of neurochemistry—is the fear that, bearing in mind the IQs of military leaders, they might use it on our own troops: “Fight? We don’t want the enemy to fight! We want them not to fight! We want our troops to fight harder!”) There are chemicals that distinguish nestmates from interlopers, that attract mates (for the few that can make use of them), that warn of danger, that cause ants to congregate; in higher concentrations, the last chemical indicates that a nestmate has been injured and throws the ants into attack mode, ready to sacrifice their lives to protect the colony. But the chemicals that concern us here are those used for communication, and the question to be answered is not “What?” but “How?”