Darwin's Dangerous Idea - Evolution and the Meaning of Life

200 BIOLOGY IS ENGINEERING Original Sin and the Birth of Meaning 201
over those that do not avail themselves of it, that yields a retroactive endorsement
of this raison d'etre of the DNA language. This is the way evolution
always discovers reasons—by retroactive endorsement.
4. ORIGINAL SIN AND THE BIRTH OF MEANING
The road to wisdom?
Well, it's plain and simple to express:
Err and err and err again
but less and less and less.
- Piet Hein
The solution to the problem of life is seen in the vanishing of this problem.
—LUDWIG WITTGENSTEIN 1922, prop. 6.521
Once upon a time, there was no mind, and no meaning, and no error, and
no function, and no reasons, and no life. Now all these wonderful things
exist. It has to be possible to tell the story of how they all came to exist, and
that story must pass, by subtle increments, from elements that manifestly lack
the marvelous properties to elements that manifestly have them. There will
have to be isthmuses of dubious or controversial or just plain unclas-sifiable
intermediates. All these wonderful properties must have come into existence
gradually, by steps that are barely discernible even in retrospect.
Recall that in the previous chapter it seemed to be obvious, maybe even a
truth of logic, that either there had to be a First Living Thing or there had to
be an infinite regress of Living Things. Neither horn of the dilemma would
do, of course, and the standard Darwinian solution, which we will see over
and over again, was this: in its place we described a finite regress, in which
the sought-for marvelous property (life, in this case) was acquired by slight,
perhaps even imperceptible, amendments or increments.
Here is the most general form of the schema of Darwinian explanation.
The task of getting from the early time when there wasn't any x to the later
time when there is lots of x is completed by a finite series of steps in which it
becomes less and less clear that "there still isn't any x here, not really,"
through a series of "debatable" steps until we eventually find ourselves on
steps where it is really quite obvious that "of course there is x, lots of x" We
never draw any lines.
Notice what happens in the particular case of the origin of life if we try to
draw the line. There are a slew of truths—no doubt largely unknowable in
detail by us—any one of which we could "in principle" identify, if we
wished, as the truth that confirms the identify of Adam the Protobacterium.
We can sharpen up the conditions on being the First Living Thing however
we like, but when we then get in our time machine and go back to witness the
moment, we find that Adam the Protobacterium, no matter how we have
defined it, is probably as undistinguished as Mitochondrial Eve. We know as
a matter of logic that there was at least one start that has us as its continuation,
but there were probably many false starts that differed in no interesting
way at all from the one that initiated the winning series. The title of
Adam is, once again, a retrospective honor, and we make a fundamental
mistake of reasoning if we ask, In virtue of what essential difference is this
the beginning of life? There need be no difference at all between Adam and
Badam, an atom-for-atom duplicate of Adam who just happened not to have
founded anything of note. This is not a problem for Darwinian theory; this is
a source of its power. As Küppers puts it ( 1990, p. 133), "The fact that we
obviously are not in a position to give a comprehensive definition of the
phenomenon 'life' speaks not against but indeed for the possibility of a
completely physical explanation of life phenomena."
Exactly the same gratuitous predicament faces anyone who, despairing of
defining something as complicated as life, decides to define the apparently
simpler notion of function or teleology. At exactly what point does function
make its appearance? Did the very first nucleotides have functions, or did
they just have causal powers? Did Cairns-Smith's clay crystals exhibit genuine
teleological properties, or just "as if teological properties? Do gliders in
the Life world have the function of locomotion, or do they just move? It
doesn't make any difference how you legislate the answer; the interesting
world of functioning mechanisms has to start with mechanisms that "straddle
the line," and, however far back you place the line, there will be precursors
that differ in arguably nonessential ways from the anointed ones. 6
Nothing complicated enough to be really interesting could have an essence.
7 This anti-essentialist theme was recognized by Darwin as a truly
6. See Bedau 1991 for an exploration of this point that arrives at a somewhat different
destination, and Linger 1990 for arguments that go directly counter to it. Linger insists we
have conventions such that there must be (on logical grounds) "straddle pairs" in such
circumstances, such that one is the last item in the series to lack x and the other is the
first in the series to have x. But as van Inwagen (1993b) observes, a more inviting
conclusion is: so much the worse for those conventions.
7. These are fighting words for some philosophers. For a clear attempt to salvage a formal
logic of essences that specifically addresses the problems raised by the complexity of
artifacts and organisms, see Forbes 1983, 1984. The conclusion I draw from Forbes' work
is that it constructs what may be a Pyrrhic victory over Quine's staunch skepticism about
essences, but in the process it confirms his underlying warning: contrary to what you
might think, there is nothing natural about essentialist thinking; seeing the world through
essentialist glasses does not at all make your life easy.