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Authors: Daniel C. Dennett

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"t" appear more frequently than, say, "u" or "j," but not because "e"s and "t"s succession of winners to be better at than just, trivially, winning the coin-are harder to erase, or easier to photocopy, or to write. (In fact, of course, the toss.

explanation runs the other way around; we tend to use the easiest-to-read-And does the new tournament ever work! There are tremendous "skill"

and-write symbols for the most frequently used letters; in Morse code, for differences between proteins, so there is plenty of room for improvement example, "e" is assigned a single dot and "t" a single dash.) In RNA and beyond the minuscule catalytic talents of the proteinoids. "In many cases, DNA, this explanation is reversed: G and C are favored because they are the enzymic catalysis accelerates a reaction by a factor between one million and most stable in replication, not because they occur most frequently in genetic one thousand million. Wherever such a mechanism has been analysed quan-

"words." This spelling bias is just "syntactic" at the outset, but it unites with titatively, the result has been the same: enzymes are optimal catalysts"

a
semantic
bias:

(Eigen 1992, p. 22). Catalytic work done creates new jobs to be done, so the feedback cycles spread out to encompass more elaborate opportunities for Examination of the genetic code [by the "philological methods"]... indi-improvement. "Whatever task a cell is adapted to, it carries out with optimal cates that its first codons were rich in G and C. The sequences GGC and efficiency. The blue-green alga, a very early product of evolution, transforms GCC code respectively for the amino acids glycine and alanine, and be-light into chemical energy with an efficiency approaching perfection" (Eigen cause of their chemical simplicity these were formed in greater abundance 1992, p. 16). Such optimality cannot be happenstance; it must be the result of

... [in the prebiotic world]. The assertion that the first code-words were a gradual homing-in process of improvement. So, from a set of tiny biases in
assigned
[emphasis added] to the most common amino acids is nothing if the initial probabilities and competences of the building blocks, a process of not plausible, and it underlines the fact that the logic of the coding scheme snowballing self-improvement is initiated.

results from physical and chemical laws and their outworkings in Nature.

[Eigen 1992, p. 34]

These "outworkings" are
algorithmic sorting processes,
which take the 3. THE LAWS OF THE GAME OF LIFE

probabilities or biases that are due to fundamental laws of physics and produce structures that would otherwise be wildly improbable. As Eigen
This most beautiful system of the sun, planets, and comets, could only
says, the resulting scheme has a logic; it is not just two things coming
proceed from the counsel and dominion of an Intelligent and Powerful
together but an "assignment," a system that comes to make sense, and makes
Being.

sense because—and only because—
it works.

—ISAAC NEWTON 1726 (passage translated in

These very first "semantic" links are of course so utterly simple and local Ellegard 1956, p. 176)

that they hardly count as semantic at all, but we can see a glimmer of
reference
in them nevertheless: there is a fortuitous wedding of a bit of
The more I examine die universe and study the details of its architec-nucleotide string with a protein fragment that helped directly or indirectly to
ture, die more evidence I find diat die universe in some sense must have
reproduce
it.
The loop is closed; and once this "semantic" assignment system
known diat we were coming.

is in place, everything speeds up. Now a fragment of code-string can be the

—FREEMAN DYSON 1979, p. 250

code
for
something—a protein. This creates a new dimension of evaluation, because some proteins are better than others at doing catalytic work, and
It is easy to imagine
a
world that, though ordered, nevertheless does not
particularly at assisting in the replication process.

possess the right sort of forces or conditions for the emergence of
This raises the stakes. Whereas at the outset, macro strings could differ
significant depth.

only in their self-contained capacity to self-replicate, now they can magnify

—PALI DAVIES 1992

their differences by creating—and linking their fates to—other, larger, structures. Once this feedback loop is created, an arms race ensues: longer and Fortunately for us, the laws of physics vouchsafe that there are, in the Vast longer macros compete for the available building blocks to build ever big-space of possible proteins, macromolecules of such breathtaking catalytic 164 PRIMING DARWIN'S PUMP

The Laws of the Game of Life
165

virtuosity that they can serve as the active building blocks of complex life.

itational attraction, the weak and strong forces of subatomic interaction, And, just as fortunately, the same laws of physics provide for just enough Planck's constant—have values that of course permit the actual development nonequilibrium in the world so that algorithmic processes can jump-start of the universe as we know it to have happened. But it turns out that if in themselves, eventually discovering those macromolecules and turning them imagination we change any of these values by just the tiniest amount, we into tools for another wave of exploration and discovery. Thank God for thereby posit a universe in which none of this could have happened, and those laws!

indeed in which apparently nothing life-like could ever have emerged: no Well? Shouldn't we? If the laws were any different, we have just seen, the planets, no atmospheres, no solids at all, no elements except hydrogen and Tree of Life might never have sprung up. We may have figured out a way of helium, or maybe not even that—just some boring plasma of hot, undiffer-excusing God from the task of designing the replication-machinery system entiated stuff, or an equally boring nothingness. So isn't it a wonderful fact (which can design itself automatically if any of the theories discussed in the that the laws
are just right
for us to exist? Indeed, one might want to add, we previous section are right, or on the right track) but even if we concede that almost didn't make it!

this is so, we still have the stupendous fact that the laws
do
permit this Is this wonderful fact something that needs an explanation, and, if so, what wonderful unfolding to happen, and that has been quite enough to inspire kind of explanation might it receive? According to the Anthropic Principle, many people to surmise that the Intelligence of the Creator is the Wisdom of we are entitled to infer facts about the universe and its laws from the the Lawgiver, instead of the Ingenuity of the Engineer.

undisputed fact that we (we
anthropoi,
we human beings) are here to do the When Darwin entertains the idea that the laws of nature are designed by inferring and observing. The Anthropic Principle comes in several flavors.

God, he has distinguished company, past and present. Newton insisted that (Among the useful recent books is Barrow and Tipler 1988 and Breuer 1991.

the original arrangement of the universe was inexplicable by "meer natural See also Pagels 1985, Gardner 1986.)

causes" and could only be ascribed to "the Counsel and Contrivance of a In the "weak form," it is a sound, harmless, and on occasion useful ap-Voluntary Agent." Einstein spoke of the laws of nature as the "secrets of the plication of elementary logic: if
x
is a necessary condition for the existence Old One" and famously expressed his disbelief in the role of chance in of
y,
and
y
exists, then
x
exists. If consciousness depends on complex quantum mechanics by proclaiming
"Gott wiirfelt nicht"
—God does not play physical structures, and complex structures depend on large molecules dice. More recently, the astronomer Fred Hoyle has said, "I do not believe composed of elements heavier than hydrogen and helium, then, since we are that any scientist who examined the evidence would fail to draw the conscious, the world must contain such elements.

inference that the laws of nuclear physics have been deliberately designed But notice that there is a loose cannon on the deck in the previous with regard to the consequences they produce inside the stars" (quoted in sentence: the wandering "must." I have followed the common practice in Barrow and Tipler 1988, p. 22). The physicist and cosmologist Freeman ordinary English of couching a claim of necessity in a technically incorrect Dyson puts the point much more cautiously: "I do not claim that the archi-way. As any student in logic class soon learns, what I really should have tecture of the universe proves the existence of God. I claim only that the written is:

architecture of the universe is consistent with the hypothesis that mind plays an essential role in its functioning" (Dyson 1979, p. 251). Darwin himself
It must be the case that:
if consciousness depends ... then, since we are was prepared to propose an honorable truce at this point, but Darwinian conscious, the world
contains
such elements.

thinking carries on, with a momentum created by the success of its earlier applications to the same issue in other contexts.

The conclusion that can be validly drawn is only that the world
does
contain As more and more has been learned about the development of the universe such elements, not that it
had to
contain such elements. It
has to
contain such since the Big Bang, about the conditions that permitted the formation of elements
for us to exist,
we may grant, but it might not have contained such galaxies and stars and the heavy elements from which planets can be formed, elements, and if that had been the case, we wouldn't be here to be dismayed.

physicists and cosmologists have been more and more struck by the exquisite It's as simple as that.

sensitivity of the laws of nature. The speed of light is approximately 186,000

Some attempts to define and defend a "strong form" of the Anthropic miles per second. What if it were only 185,000 miles per second, or 187,000

Principle strive to justify the late location of the "must" as not casual ex-miles per second? Would that change much of anything? What if the force of pression but a conclusion about the way the universe necessarily is. I admit gravity were 1 percent more or less than it is? The fundamental constants of that I find it hard to believe that so much confusion and controversy are physics—the speed of light, the constant of grav-actually generated by a simple mistake of logic, but the evidence is really

166 PRIMING DARWIN'S PUMP

The Laws of the Game of Life
167

quite strong that this is often the case, and not just in discussions of the Anthropic Principle. Consider the related confusions that surround Darwinian deduction in general. Darwin deduces that human beings
must have
evolved from a common ancestor of the chimpanzee, or that all life
must have
arisen from a single beginning, and some people, unaccountably, take these deductions as claims that human beings are somehow a necessary product of evolution, or that life is a necessary feature of our planet, but nothing of the kind follows from Darwin's deductions properly construed. What must be the case is not that we are here, but that
since
we are here, we evolved from primates. Suppose John is a bachelor. Then he
must
be single, right? (That's a truth of logic.) Poor John—he can never get married! The fallacy is obvious in this example, and it is worth keeping it in the back of your mind as a template to compare other arguments with.

Believers in any of the proposed strong versions of the Anthropic Principle think they can deduce something wonderful and surprising from the FIGURE 7.2

fact that we conscious observers are here—for instance, that in some sense the universe exists
for
us, or perhaps that we exist
so that
the universe as a whole can exist, or even that God created the universe the way He did so that is either ON or OFF at each moment. (If it is ON, place a penny on the square; we would be possible. Construed in this way, these proposals are attempts to if it is OFF, leave the square empty.) Notice in figure 7.2 that each cell has restore Paley's Argument from Design, readdressing it to the Design of the eight neighbors: the four adjacent cells—north, south, east, and west—and universe's most general laws of physics, not the particular constructions those the four diagonals—northeast, southeast, southwest, and northwest.

laws make possible. Here, once again, Darwinian coun-termoves are Time in the Life world is discrete, not continuous; it advances in ticks, and available.

the state of the world changes between each two ticks according to the These are deep waters, and most of the discussions of the issues wallow in following rule:

technicalities, but the logical force of these Darwinian responses can be brought out vividly by considering a much simpler case. First, I must in-Life Physics: For each cell in the grid, count how many of its eight neigh-troduce you to the Game of Life, a nifty meme whose principal author is the bors are ON at the present instant. If the answer is exactly two, the cell stays mathematician John Horton Conway. (I will be putting this valuable thinking in its present state ( ON or OFF ) in the next instant. If the answer is exactly three, the cell is

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