There is a grave and unmistakable lack of intermediates in the
fossil record. The fact that creationists gloat over it should not tempt
others to ignore it. The "fossil gaps" were a hole in Darwin's theory
that he promised would go away in the future, when more areas of Earth
were searched by professional evolutionists. The gaps did not go away in
the least. Once a "trade secret" of paleontologists, the gaps are now
acknowledged by every leading authority on evolution. Here are two: "The
known fossil record fails to document a single example of phyletic
[gradual] evolution accomplishing a major morphologic transition and
hence offers no evidence that the gradualistic model can be valid," says
Stephen Stanley, evolutionary paleontologist. And here's Steven Jay
Gould again, speaking as the expert paleontologist he is:
All paleontologists know that the fossil record contains precious little
in the way of intermediate forms; transitions between major groups are
characteristically abrupt....The history of most fossil species includes
two features particularly inconsistent with gradualism:
1. Stasis. Most species exhibit no directional change during their
tenure on Earth. They appear in the fossil record looking much the same
way as when they disappear....
2. Sudden appearance. In any local area, a species does not arise
gradually by the steady transformation of its ancestors; it appears all
at once and "fully formed."
In the eyes of science historians, Darwin's most consequential claim was
that the discontinuous face of life as a whole was an illusion. The
separateness of species, the "immutable essence" intrinsic to each type
of animal or plant -- a principle which the ancient philosophers had taught
forever -- was, he claimed, false. The Bible spoke of creatures "each made
in their kind," and most biologists of the day, including the young
Darwin, thought species kept to their breed in an idealized way. It was
the type that mattered, while individuals conformed more or less to the
type. The enlightened Darwin announced, however, that (1) every
individual differed significantly; (2) all life was dynamically plastic,
infinitely malleable between individuals, so (3) individuals arranged
in populations were all that mattered. The barriers erected by species
were porous and illusory. By shifting the discontinuity from species to
every individual, Darwin vaporized it. Life was one evenly distributed
being.
But intriguing suspicions now accumulating in the study of complex
systems, particularly complex systems that adapt, learn, and evolve,
suggest Darwin was wrong in his most revolutionary premise. Life is
largely clumped into parcels and only mildly plastic. Species either
persist or die. They transmute into something else under only the most
mysterious and uncertain conditions. By and large, complex things fall
into categories and the categories persist. Stasis of the category is
the norm: the typical lifespan for a species is between one and ten
million years.
Things that resemble organisms -- economic firms, thoughts in the brain,
ecological communities, nation-states -- also naturally differentiate into
persistent clumps. Human institution clumps -- churches, departments,
companies -- find it easier to grow than to evolve. Required to adapt too
far from their origins, most institutions will die.
"Organic" entities are not infinitely malleable because complex systems
cannot easily be gradually modified in a sequence of functional
intermediates. A complex system (such as a zebra or a company) is
severely limited in the directions and ways it can evolve, because it is
a hierarchy composed entirely of subentities, which are also limited in
their room for adaptation because they are composed of sub-subentities,
and so on down the tower.
It should be no surprise, then, to find that evolution works in quantum
steps. The given constituents of an organism can collectively make this
or that, but not everything in between this and that. The hierarchical
nature of the whole prevents it from reaching all the possible states it
might theoretically hit. At the same time, the hierarchical arrangement
of the whole gives it power to make some large-scale shifts. So a record
of this organism would show it leaping from this to that. In biology,
this is called saltationism (from the Latin saltare, to jump) and it is
totally out of favor among professional biologists. Mild saltationism
was rejuvenated with interest in Goldschmidt's genetic hopeful monsters,
but a complex saltationism that would significantly leap over
transitional forms is pure heresy at the moment. Yet the interdependent
coadaptations that constitute a complex being must produce quantum
evolution. Artificial evolution has not yet produced an "organism"
complex enough to contain hierarchical depth, and so we don't know yet
in what way saltationism might appear in synthetic worlds.
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