motor of construction, must still be the processes of normal times building
creatures that will one day pass for review before the sieve of mass extinction.
And the controlling process of normal times is wedging by competition.
I could rebut this argument in several ways. I might argue, for example,
that sorting by differential death in mass extinction mimics, on a grander
scale, the ordinary mode of operation for natural selection in normal
times. Natural selection is a sieve, not a sculptor. Many are called;
few are chosen. Natural selection is powered by differential birth and
death; the few survivors accumulate and intensify their favorable features
bit by bit on the relentless sieve of each generation. What is mass extinction
but a grander sieve, sorting out species rather than organisms. If the
sorting of organisms in normal times yields change that we label as positive,
why not grant the same status to differential death in episodic catastrophes?
Mass extinction need not be viewed as a negative force opposed to progress
in normal times.
But I would choose an opposite tack to provide the other half-loaf to
the wheel of fortune. Rather than promoting the wheel of mass extinction
by its formal similarity to processes at smaller scale, I would proceed
in the reverse direction. I would argue, in short, that the fundamental
principle of quirky and unpredictable success by fortuitous side consequences
pervades all scales. This vital domain of the wheel does not "click
in" only at global catastrophe, leaving most of time to the wedge
of ordered progress. The tires-to-sandals principle works at all scales
and times, interacting with the wedge to permit odd and unpredictable
initiatives at any moment--to make nature as inventive as the cleverest
person who ever pondered the potential of a junkyard in Nairobi.
I will go further and make a statement that may seem paradoxical. The
wedge of competition has been, ever since Darwin, the canonical argument
for progress in normal times. I will claim that the wheel of quirky and
unpredictable functional shift (the tires-to-sandals principle) is the
major source of what we call progress at all scales. Advance in complexity,
improvement in design, may be mediated by the wedge up to a certain and
limited point, but long-term success requires feinting and lateral motion,
with each zig permitting another increment of advance, and progress crucially
dependent upon the availability of new channels. Evolution is an obstacle
course not a freeway; the correct analogue for long-term success is a
distant punt receiver evading legions of would-be tacklers in an oddly
zigzagged path toward a goal, not a horse thundering down the flat.
Let us take the broadest possible look at just three prerequisites for
continuity in the sequence that, in our parochialism, we view as the crucial
and representative case of evolutionary advance--the origin of human
consciousness. At each true turning point, each leap in the capacity for
substantial advance, we meet the wheel spinning its way toward a new use
for old features (sandals from tires); the wedge can only promote, for
a limited time and extent, what the wheel makes possible.
1. Origin of the genetic flexibility for major advance in complexity.
For evolutionists, perhaps the most intriguing and unexpected discovery
of molecular genetics emerged during the 1960s when study after study
proved that in multicellular organisms, only a small percentage of the
total genetic material consists of functional genes in single copies.
Most of the genetic material may be "junk" with respect to information
needed to build and maintain a working body. Moreover, many genes exist
in multiple copies for obscure reasons unrelated to the necessary functions
Nonetheless, it soon became clear to evolutionists that redundancy of
multiple copies might be the crucial prerequisite for evolution
of complexity. Suppose that the original unicellular ancestor of all complex
creatures had only one copy of each gene and that each gene coded for
a vital function. (This claim is not mere conjecture, but represents the
actual state of the simplest creatures alive today and the best models
for ultimate multicellular ancestors.) These creatures work very well;
they may be honed to an optimum by natural selection, shorn of all unneeded
fat and flab. But now, a conundrum for evolution: These creatures may
excite our admiration for efficiency, but how can they change in the crucial
sense of adding new capacities in complexity? Each gene codes for something
vital; it can only alter by improvement in its own channel. This kind
of genetic system offers no flexibility; no play, no capacity for adding
something truly new.
This conundrum led evolutionists to grasp the fundamental role of multiple
copies in permitting the evolution of complexity. If genes exist in several
copies, but only one supplies the body's functional need, then the other
copies are free to experiment, vary, and add capacity through occasional
Well and good so far, but we now face a logical puzzle: Unless we thoroughly
misunderstand the fundamental nature of causality, multiple copies cannot
arise "for" their potential use in permitting complexity millions
of years in the future. Multiple copies are the key to complexity, but
they must have evolved for other reasons--the tires-to-sandals principle
of quirky functional shift.
This case is particularly interesting because the initial reason for
duplication (harvesting of rubber for tires) may not, itself, have much
to do with natural selection as traditionally conceived in terms of organisms
struggling for reproductive success. Duplication may arise by selection
at the lower level of genes, a process invisible in the larger world of
the wedge. Genes also play the game of natural selection in their own
realm, and those that develop the capacity to duplicate and move (transposons,
or jumping genes) secure advantages at this lower level, just as organisms
win in Darwin's world by leaving more surviving offspring. In fact, gene
duplication may be abetted by producing no effect upon bodies, for invisibility
at Darwin's level of the wedge provides hiding space and assures that
no negative pressures of natural selection shall impede the accumulation
of "unneeded" extra copies. Yet these "redundant"
duplicate genes may house the latent source of later complexity.
2. The evolution of complex cells. Many biologists would place
nature's fundamental distinction not between plants and animals, or even
between unicellular and multicellular organisms, but at a division within
unicellular creatures. The structurally simple prokaryotes, bacteria and
cyanophytes, have no organelles within their cells--no nucleus or
chromosomes, no mitochondria. The complex eukaryotes have evolved the
array of internal structures that grace (or disfigure according to your
view or status) nearly every high school biology final with its inevitable
question: label all the parts of the cell and state their functions.
This increment of complexity from prokaryote to eukaryote is deemed
fundamental, in part because we view eukaryote organization as an absolute
prerequisite to the later evolution of multicellular organisms. (To cite
just one standard argument: Darwinian evolution of complexity requires
copious variation to fuel natural selection; most variation arises from
the mixture, via sexual reproduction, of two differing genetic systems
in each offspring; sexual reproduction requires a mechanism for exact
division of genetic material so that 50 percent of each parent reconstitutes
the needed 100 percent in offspring; meiosis by reduction division of
paired chromosomes is the biological in-