> The terms "mutation" and "natural selection" have been loaded up with a
> lot of metaphysical baggage. I think that's part of the problem. I'm
> hoping to unpack some of that baggage by considering closely related
> natural processes like meiosis.
Agreed. They have also been loaded up with a lot of "scientific"
baggage! There are many sources of confusion about these terms.
> Mutation, like meiosis and recombination, is a natural process in DNA
> governed by the laws of physics and chemistry which God designed. Is it
> proper to think of mutation as a malfunction? Only if biological
> reproduction was designed to have 100% fidelity. When computer
> programmers use a genetic algorithm, they deliberately design less-than-
> 100% fidelity into reproduction from generation to generation.
This SEEMS to me to confuse the complex mechanisms that are available
for achieving variation (and which are exploited by plant and animal
breeders) with the malfunctioning of that machinery to produce
mutations.
> God
> designed the natural laws which govern the replication of DNA during
> reproduction. I imagine God could have designed the system for 100%
> fidelity. Thank God he didn't! ;-) Mutations play an important role
> over the long term, allowing populations of plants and animals to adapt
> to changing geological conditions, and allowing them to take advantage
> of new ecological niches.
I think, Loren, that you are wanting to put everything that produces
variability into the "mutation" category - and I find this very
confusing.
variability plays an important role over the long term, ... but I see
this as the effective use of the complex cellular machinery. How do
we know that "mutations" (malfunctions) play an important role? If
it is so important, it has presumably been well studied - and there
should be no difficulty finding dozens of examples to support the
hypothesis. However, I am not aware of the long list and am very
skeptical about its reality. (Hence, by putting all sources of
variability under the heading "mutation", an important distinction
in the sources of variability is obscured).
> In the big picture, mutations should be
> thought of as a design feature of the system, not a bug. A particular
> mutation event sometimes produces an individual with genetic combination
> which is harmful or fatal.
It may be helpful to refer to the complex cellular repair mechanisms
at this point. The "direction" of the repair work establishes in my
mind what can properly be described as a "design feature". That
variability which is designed is not "repaired", but that which is
associated with malfunctioning is. Of course, some malfunctions are
so severe that they fall outside the capabilities of the repair
apparatus.
[BTW, I am happy to be corrected on any of this - the pace of
research is so fast that it is inevitable that knowledge becomes
dated].
> The same is true of meiosis and
> recombination! From a scientific description, these processes are not
> entirely deterministic; they contain a random element. Theologically,
> we know that God designed that flexibility into the system, and nothing
> "random" happens outside of God's will. (I'll leave aside the
> Calvinist/Armenian interpretations of that for now.)
Agreed. I have no problem with this point.
> In your response to me, you used the term "design" as refering to the
> specific features of a species or an individual. If this is the *only*
> way you think of "design," then I agree that mutation and natural
> selection seem like crude instruments for achieving them (even if every
> "random" event is precisely determined along the way). De novo creation
> would seem like a much sharper instrument to achieve design at the level
> of species and individuals.
OK. I would probably lean to the "Family" as the taxonomic level
of importance, rather than "species or an individual". I am grateful
for the comment that Darwinian mechanisms "seem like crude
instruments" for achieving this design. However, I am certainly open
to design being apparent in a broader context.
> But there are additional ways we should think about "design" --
> first of all, at the level of the basic laws of nature;
Yes, Agreed.
> secondly, at the level of a complex, inter-linked ecosystem
> designed to continue and evolve over a long period. At that level,
> mutation and natural selection do not seem (to me) to be "crude tools"
> at all. They are such remarkably good design features that we are
> beginning to copy them into our own technology and research.
If you are talking about that which has been called "microevolution",
then we are not so far apart. However, even here, I have my doubts
that the mechanisms involved are Darwinian.
As for the point about "beginning to copy them into our own
technology and research", I assume you are referring to genetic
algorithms. On and off, this topic has been raised on this list -
but I have always felt that the consensus was that GAs can only be
effective in a highly structured contect, where the researcher or
engineer has clear design goals and carefully constructs the
algorithms to facilitate solutions. Failure to do this just leads to
studies that are computationally intractable. In other words, GAs
can be extremely blunt instruments unless they are carefully managed
and well designed.
> And since
> no "random" event happens outside God's control, God can equally well
> use mutation and natural selection to implement additional "design" at
> the level of species and individuals.
It is true that there are no events outside God's control - but this
does not make it more likely that blunt instruments will be the means
God uses to achieve his design purpose. Nor does this allow us to
use the word "wisdom" to describe the results of his actions. If it
were not for the pervasive influence of Darwinian thinking in
biology, would we give so much credence to the appropriateness of
mutation and natural selection as mechanisms? (Bur perhaps this
brings us back again to what the word "mutation" actually means!).
Best wishes,
David J. Tyler.