I followed the link given by Wesley, to Jonathon Wells's web pages. Besides
the usual discredited ID arguments, I found one that I haven't seen before:
"To a very limited extent, it [DNA] also contains information about the
order in which those proteins should be produced-assembly instructions. But
it does not contain the basic floor plan. The floor plan and many of the
assembly instructions reside elsewhere (nobody yet knows where). Since
development of the embryo is not programmed by the DNA, the Darwinian view
of evolution as the differential survival of DNA mutations misses the point.
At most, Darwin's theory may explain "microevolution" within established
lineages-such as minor differences among closely related species of
salamanders. But it cannot account for "macroevolution," - the large-scale
differences between shellfish and insects, or between birds and mammals."
Jonathon Wells
(http://www.tparents.org/Library/Unification/Talks/Wells/DARWIN.htm)
This argument can be disposed of fairly easily. First, no "floor plan" is
required. To bake a cake, you don't need a picture of the cake--you just
need a recipe. Similarly, the development of the embryo is controlled by
proteins expressed by the DNA. The timing of this process and the
interaction of the proteins is no doubt amazingly complex, but it is,
essentially, a process whose steps are encoded in the DNA, somewhat like the
instructions in a computer program. There is no need for a miniature model
or plan of the organism to work from.
Wells also claims that "many of the assembly instructions reside elsewhere".
I wonder what is his basis for this claim. It sounds like another God-of-the
Gaps argument to me. There are a great many genes whose purpose we don't
know, and it seems clear that, as the functions of these genes are learnt,
this gap will shrink, as so many other God-shaped gaps have done in the
past.
But, just for the sake of argument, let's suppose that the assembly
instructions are not all in the DNA. What would be the implications of that?
Well, if they are included in some other inherited material, it doesn't
really matter. Providing the copying of that material is imperfect, it will
be subject to random variation and will provide the material for evolution,
just like DNA. In fact, this is, in a sense, the case. The development of
the embryo is controlled not just by DNA, but also by environmental factors,
particularly the nature of the egg and the input of the parents
(particularly in placental species). But these factors are themselves
primarily determined by the DNA, and so are subject to random variation and
natural selection.
Remember, Darwin knew nothing about DNA, but formulated the theory of
evolution in terms of random variation and natural selection (and
inheritance, which is vital but usually taken for granted). All evolution
requires is that the assembly instructions be inherited and subject to
random variations. The details of the mechanisms of inheritance and
variation don't matter.
And, if the assembly instructions aren't inherited, then where do they come
from? Perhaps Wells believes in some sort of divine input at every
conception or during embryonic development. But I see no reason why the rest
of us should accept such a belief.
Richard Wein (Tich)
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