Darwin's Dangerous Idea (64 page)

have been dominant for millions of years can vanish overnight; and, of People ache to believe that we human beings are vastly different from all course, new selection pressures can come into existence with a single other species—and they are right! We are different. We are the only species volcanic eruption, or the appearance of a new disease organism.

that has an
extra
medium of design preservation and design communication: Cultural evolution operates many orders of magnitude faster than genetic culture. That is an overstatement; other species have rudiments of culture as evolution, and this is part of its role in making our species special, but it has well, and their capacity to transmit information "behaviorally" in addition to also turned us into creatures with an entirely different outlook on life from genetically is itself an important biological phenomenon (Bonner 1980 ), but that of any other species. In fact, it isn't clear that the members of any other these other species have not developed culture to the takeoff point the way species
have
an outlook on life. But we do; we can choose celibacy for our species has. We have language, the primary medium of culture, and reasons; we can pass laws regulating what we eat; we can have elaborate language has opened up new regions of Design Space that only we are privy systems for encouraging or punishing certain sorts of sexual behavior, and so to. In a few short millennia—a mere instant in biological time—we have forth. Our outlook on life is so compelling and obvious to us that we often already used our new exploration vehicles to transform not only our planet fall in the trap of imposing it willy-nilly on other creatures—or on all of but the very process of design development that created us.

nature. One of my favorite examples of this widespread cognitive illusion is Human culture, as we have already seen, is not just a crane composed of the puzzlement researchers have expressed about the evolutionary ex-cranes, but a crane-making crane. Culture is such a powerful set of cranes planation of sleep.

that its effects can swamp many—but not all—of the earlier genetic pressures Lab shelves sag beneath volumes of data, yet no one has discerned that and processes that created it and still coexist with it. We often make the sleep has any clear biological function. Then what evolutionary pressure mistake of confusing a cultural innovation with a genetic innovation. For selected this curious behavior that forces us to spend a third of our lives instance, everybody knows that the average height of human beings has unconscious? Sleeping animals are more vulnerable to predators. They skyrocketed in the last few centuries. (When we visit such relics of recent have less time to search for food, to eat, to find mates, to procreate, to feed history as
Old Ironsides,
the early-nineteenth-century warship in Boston their young. As Victorian parents told their children, sleepy-heads fall be-Harbor, we find the space below decks to be comically cramped—were our hind—in life and evolution.

ancestors really a race of midgets?) How much of this rapid change in height University of Chicago sleep researcher Allan Rechtshaffen asks "how is due to genetic changes in our species? Not much, if any at all. There has could natural selection with its irrevocable logic have 'permitted' the an-been time for only about ten generations of
Homo sapiens
since
Old Iron-imal kingdom to pay the price of sleep for no good reason?" Sleep is so
sides
was launched in 1797, and even if there were a strong selection pressure apparently maladaptive that it is hard to understand why some other con-favoring the tall—and is there evidence for that?—this would not have had dition did not evolve to satisfy whatever need it is mat sleep satisfies.

time to produce such a big effect. What have changed dramatically are human

[Raymo 1988.]

health, diet, and living conditions; these are what have produced the dramatic change in phenotype, which is 100 percent due to cultural innovations, passed But why does sleep need a "clear biological function" at all? It is
being
on through cultural transmission: schooling, the spread of new farming
awake
that needs an explanation, and presumably its explanation is obvious.

practices, public-health measures, and so forth. Anyone who worries about Animals—unlike plants—need to be awake at least part of the time, in order

"genetic determinism" should be reminded that virtually all the differences to search for food and procreate, as Raymo notes. But once you've headed discernible between the people of, say, Plato's day and the people living down this path of leading an active existence, the cost-benefit analysis of the today—their physical talents, proclivities, attitudes, prospects—must be due options that arise is far from obvious. Being awake is relatively costly, to cultural changes, since fewer than two hundred generations separate us compared with lying dormant (think of its root,
dormire).
So presumably from Plato. Environmental changes due to cultural innovations change the Mother Nature economizes where she can. If we could get away with it, we'd landscape of phenotypic expression so much, and so fast, however, that they

"sleep" our entire lives. That is what trees do, after all: all winter they can in principle change the genetic selection pressures rapidly—the Baldwin

"hibernate" in deep coma, because there is nothing else for them to do, and in Effect is a simple instance of such a change in selection pressure due to the summer they "estivate" in a somewhat lighter coma, in what the doctors widespread behavioral innovation. Although it is important to remember how call a
vegetative state
when a member of our species has the misfortune to slowly evolution works in general, we should

enter it. If the woodchopper comes along while the tree 340 THE CRANES OF CULTURE

The Monkey's Uncle Meets the Meme
341

is sleeping, well, that's just the chance that trees have to take, all the time.

Then a few billion years passed, while multicellular life forms explored But surely we animals are at greater risk from predators while we sleep? Not various nooks and crannies of Design Space until, one fine day, another necessarily. Leaving the den is risky, too, and if we're going to minimize that invasion began, in a single species of multicellular organism, a sort of pri-risky phase, we might as well keep the metabolism idling while we bide our mate, which had developed a variety of structures and capacities (don't you time, conserving energy for the main business of replicating. (These matters dare call them preadaptations) that just happened to be particularly well are much more complicated than I am portraying them, of course. My point suited for these invaders. It is not surprising that the invaders were well is just that the cost-benefit analysis is far from obvious, and that is enough to adapted for finding homes in their hosts, since they were themselves created remove the air of paradox.)

by their hosts, in much the way spiders create webs and birds create nests. In
We
think that being up and about, having adventures and completing a twinkling—less than a hundred thousand years—these new invaders projects, seeing our friends and learning about the world, is the whole point transformed the apes who were their unwitting hosts into something of life, but Mother Nature doesn't see it that way at all. A life of sleep is as altogether new:
witting
hosts, who, thanks to their huge stock of newfangled good a life as any other, and in many regards better—certainly cheaper—

invaders, could imagine the heretofore unimaginable, leaping through Design than most. If the members of some other species also seem to
enjoy
their Space as nothing had ever done before. Following Dawkins ( 1976), I call the periods of wakefulness as much as we do, this is an interesting commonality, invaders
memes,
and the radically new kind of entity created when a so interesting that we should not make the mistake of assuming it must exist particular sort of animal is properly furnished by—or infested with— memes just because we find it to be such an appropriate attitude towards life in our is what is commonly called a
person.

own case. Its existence in other species needs to be shown, and that is not That is the story in rough outline. Some people, I have found, just hate the easy.1

whole idea. They like the idea that it is our human minds and human culture
What we are
is very much a matter of what culture has made us. Now we that distinguish us sharply from all the "thoughtless brutes" (as Descartes must ask how this all got started. What sort of evolutionary revolution called them ), but they don't like the idea of trying to give an evolutionary happened that set us apart so decisively from all the other products of genetic explanation of the creation of this most important distinguishing mark. I revolution? The story I am going to tell is a retelling of the story we think they are making a big mistake.2 Do they want a miracle? Do they want encountered in chapter 4, about the creation of the eukaryotic cells that made culture to be God-given? A skyhook, not a crane? Why? They want the multicellular life possible. You will recall that before there were cells with human way of life to be radically different from the way of life of all other nuclei there were simpler, and more solitary, life forms, the prokary-otes, living things, and so it is, but, like life itself, and every other wonderful thing, destined for nothing fancier than drifting around in an energy-rich soup culture must have a Darwinian origin. It, too, must grow out of something reproducing themselves. Not nothing, but not much of a life. Then, one day, less, something
quasi-,
something merely
as if
rather than
intrinsic,
and at according to Lynn Margulis' wonderful story (1981), some prokaryotes were every step along the way the results have to be, as David Haig puts it, invaded by parasites of sorts, and this turned out to be a blessing in disguise,
evolutionarily enforceable.
For culture we need language, for instance, but for, whereas parasites are—by definition—deleterious to the fitness of their language has to evolve on its own hook first; we can't just notice how good it hosts, these invaders turned out to be beneficial, and hence were
symbionts
would be once it was all in place. We can't presuppose cooperation; we can't but not parasites. They and those they invaded became more like presuppose
human
intelligence; we can't presuppose tradition— this all has to
commensals
—literally, from the Latin, organisms that feed at the same be built up from scratch, just the way the original replicators were. Settling table—or
mutualists,
benefiting from each other's company. They joined for anything less in the way of an explanation would be just giving up.

forces, creating a revolutionary new kind of entity, a eukaryotic cell. This In the next chapter, I will address the important theoretical questions opened up the Vast space of possibilities we know as multicellular life, a space previously unimaginable, to say the least; prokaryotes are no doubt clueless on all topics.

2. It has been made before, by no less stalwart a Darwinian than Thomas Henry Huxley, in his Romanes Lecture of 1893 in Oxford. "Huxley's critics ... noted the apparent bifurcation he had introduced into nature, between natural processes and human activity, 1. See the discussion of fun in Dennett 1991a. Some human beings claim to love to sleep.

as if man could somehow lift himself out of nature" (Richards 1987, p. 316). Huxley

"What do you plan to do this weekend?" "Sleep! Ahh, it will be wonderful!" Other human quickly saw his error and attempted to restore a Darwinian account of culture—by an beings find this attitude well-nigh incomprehensible. Mother Nature sees nothing strange appeal to the force of group selection! History does have a way of repeating itself.

about either attitude, under the right conditions.

342 THE CRANES OF CULTURE

Invasion of the Body-Snatchers
343

about how language and the human mind could evolve in the first place by in a Mandel Lecture to the American Society for Aesthetics, a lecture series Darwinian mechanisms. I will have to confront and disarm the tremendous—

endowed for the purpose of exploring the question whether art promotes and largely misguided—animosity to this story, and also work out answers to human evolution. (The answer is Yes!) I then exapted my own device, the responsible objections to it. But before we consider how this magnificent reusing it, with modifications, in my book on human consciousness (1991a, crane-structure might have been built, I want to sketch the completed pp. 199-208), to show how memes could transform the operating system or product, distinguishing it from its caricatures, and showing in a little more computational architecture of a human brain. That account offers many detail how culture comes to have such revolutionary powers.

details about the relationship between the genetically designed hardware of the human brain and the culturally transmitted habits that transform it into something much more powerful, and I will skip lightly over most of those 2. I

details here. This time I will modify my exaptation of Dawkins a second NVASION OF THE BODY-SNATCHERS

time, the better to deal with the particular environmental problems encountered in the current explanatory project. (Those who are familiar with
Human beings owe their biological supremacy to the possession of a
either of its immediate ancestors should find important improvements in the
form of inheritance quite unlike that of other animals: exogenetic or
current version.)

exosomatic heredity. In this form of heredity information is transmitted
The outlines of the theory of evolution by natural selection make clear that
from one generation to the next through nongenetic channels
—
by word
evolution occurs whenever the following conditions exist:
of mouth, by example, and by other forms of indoctrination; in general,
by the entire apparatus of culture.