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Both "Progressive Creation" and "Theistic Evolution" agree that most
of the developmental history of plants and animals was governed by the
ordinary processes of natural law, and that "Anyone who is a fully
biblical theist must consider ordinary processes controlled by natural law
to be as completely and deliberately the wonderful acts of God as any
miracle, equally contingent upon his free and unhindered will."[1]
[1] D. Wilcox, as quoted in R.T. Wright in _Biology_Through_the_
_Eyes_of_Faith_. Harper & Row, New York, NY, p. 110.
The difference, as I understand it, is this: Theistic Evolution
hypothesizes that these God-ordained, "ordinary" natural laws can (and
eventually will) provide an adequate account of the developmental history
of plants and animals, whereas Progressive Creation asserts that an
adequate account must ALSO include God's supernatural activity at various
times and places in history (to introduce new lifeforms and/or new
biological features and/or new genetic information).
Critics of Theistic Evolution argue that Progressive Creation "fits the
data better," and that -- unless and until biologists can prove that there
are specific natural mechanisms to account for various biological
developments (e.g. the origins of life, the Pre-Cambrian explosion, the
development of wings and eyes and ears, the reptile-to-bird transition,
etc.) -- Progressive Creation should be the "theory of choice" for
Christians (and perhaps for non-Christians as well).
I wish to critique the claim that "Progressive Creation fits the
(scientific and theological) data better than Theistic Evolution."
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Imagine a straight-line-plus-scatter data set -- for example, an
experimental measurement of velocity vs. time for a falling object. A
quadratic equation fits the data better than a linear equation, and a
cubic fits better than a quadratic. The "extra degree of freedom" always
produces a better fit to the data.
When does the data warrant the addition of another "degree of freedom" to
the theory? Simply "fitting the data better" is not sufficient. It
typically depends upon a combination of two factors:
(1) How MUCH improved is the fit to the data? (This depends in part
on the size of the error bars.)
(2) Is there a compelling theoretical reason to expect the extra
degree of freedom?
(In this example, well-known additional forces such as air friction could
provide a compelling reason to expect non-linear behavior. But if the
experiment were performed in a carefully controlled, frictionless
environment, where no forces other than gravity are believed to act on the
object, the "improved fit" to the data (taking into account the size of
the error bars) would have to be very compelling in its own right to
warrant a non-linear hypothesis. (As evidenced by the occasional
"fifth-force experiments."))
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Progressive Creation can be thought of as Theistic Evolution with an
"extra degree of freedom," namely, God's supernatural activity at various
points in the developmental history of plants and animals. Is there a
compelling theological reason to expect this?
It is sometimes argued that the creation account in Genesis 1 provides
support for the hypothesis that God performed specific, miraculously
creative acts at several times during the developmental history of plants
and animals. But if this so, the same reasoning should apply to the
developmental history of the sun, moon, stars, and earth. However,
their formation can be adequately described, scientifically, through the
operation of natural laws over several billion years. If "Theistic
Evolution" is a theologically acceptable interpretation of the creation of
the physical structures of the universe, then it should also be
theologically acceptable for the developmental history of plants and
animals.
The natural mechanisms which God has created, and by which he ordinarily
governs the biological world, are extremely complex and wondrous.
Despite our lack of detailed scientific understanding of processes such as
zygotic development and microevolution, we believe that these "natural
mechanisms" are the means by which God brings new individuals into the
world, and the means by which existing species can adapt to changes in
their environment.
Therefore, I conclude that Progressive Creation does not significantly
"fit the theological data" better than Theistic Evolution.
------------------------
Perhaps the greatest source of debate in this discussion group is the
_scientific_ data. The classical "Gradualist" model of evolution
postulates that every mutation in the genome causes, at most, a small
change in the organism's morphology. Those mutations which are beneficial
(i.e. increase the organism's reproductive abilities) are slowly
distributed throughout the population, and in this way -- gradually
through thousands of intermediate morphological steps -- a new species
evolves. The scientific data, specifically the fossil record, seems to
disagree fairly emphatically with the simple Gradualist model. I would
say that Progressive Creation fits the data decisively better than the
Gradualist model.
However, simple Gradualism does not really represent what we know -- and
what we know that we DON'T know -- about evolution. We know that a single
mutation in a gene which controls the developmental program of an organism
can cause a major morphological change. Processes such as gene
duplication and gene transfer can also increase the speed of evolutionary
changes. We know of several modern examples of new species evolving in a
few thousand years in small, geographically isolated populations. But
perhaps most importantly, we are painfully aware that we still know very
little about how an organism's genomic information maps into the
morphology or "fitness" of adult organisms. Except for a few special
cases, we do not yet have the ability to predict how specific mutations
affect the body structure or reproductive success of an individual. We
simply don't know the extent to which purely "natural mechanisms" can
cause evolutionary changes over a few million years. The "error bars," if
you will, are still too large. Given our current level of scientific
understanding, the "error bars" on the natural mechanisms are, I believe,
large enough to cover the fossil record data.
That is why I conclude that Progressive Creation does not significantly
"fit the scientific data" better than Theistic Evolution.
----------------------
If Progressive Creation fits the data at least as well as Theistic
Evolution, why not embrace it and advocate it as the "antidote" to
Naturalistic Evolution? Progressive Creation, when carefully formulated,
is not equivalent to "God-of-the-Gaps." But there is a significant danger
that, if biological evolutionary theory ultimately achieves a firm
empirical grounding (as stellar evolutionary theory has done), Progressive
Creation could fall into the same apologetic demise as God-of-the-Gaps.
That is why I advocate Theistic Evolution as the antidote to Naturalistic
Evolution.
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In theory, there is no difference between | Loren Haarsma
theory and practice, but in practice | lhaarsma@opal.tufts.edu
there is a great deal of difference. |