Re: humans irreducibly complex?

Brian D Harper (
Fri, 28 May 1999 14:31:59 -0700

At 05:54 PM 5/24/99 GMT, you wrote:
>Rich Daniel wrote:
>> In a very few years, we'll know the complete DNA sequences for man, chimp,
>> and gorilla. I'll make you a bet: There will be no human genes that are
>> not also in chimps and gorillas, with very minor differences. (Actually
>> it's just barely possible that there could be one or two genes extra in
>> humans, because they were deleted during the evolution of chimps, but those
>> would be found in gorillas. Another source of extra genes would be
>> retroviral insertions, but those should leave traces showing their viral
>> origins.)
>I know you have offered this "bet" to Paracelsus, but before this
>exchange gets too polarised, I would like to inject the thought that
>creationists have no reason to take you up on it. Design
>considerations suggest that the task of DNA is very similar for Apes
>and mankind - the DNA ought to be very similar.

Hello David. I would agree that this type of argument seems
consistent with the views of intelligent design folks today.
But there are some aspects of this argument that I don't
understand. I would like to raise several questions in the
context of what I'll call the "traditional" teleological
argument which was common before Darwin and espoused by
individuals such as Cuvier.

In this argument, teleology implies optimality of the match
between form and function which in turn implies uniqueness.
Why? Because the teleologist wanted to provide an explanation
for form, to give an answer to the question "why this form?".
The answer is "because this form is optimal with respect to
this function." The answer requires uniqueness or else it
fails to explain. So, my first question would be whether
the uniqueness of form to function is still held by design
folks today. [BTW, I would invite answers from anyone for
all my questions]

OK, your statement above certainly seems consistent with
the "traditional" view. The DNA is presumably optimally
suited to its "task" for both humans and apes. But we seem
to have another idea inherent in your argument, namely that
there is a continuity between the optimal relation between
form and function. A neighboring point in function-space
being optimally related to a neighbor in form-space. So,
my next question would be why such a continuity would not
suggest the possibility of evolution?

My final question relates to a different type of homology.
Similar forms with different functions. As I understand it,
this is what did Cuvier in. The reason is that this type
of homology seems to destroy the uniqueness relation and
without that one can no longer give a teleological explanation
for the question I mentioned above "why this form?". So,
I guess my question here would be how modern design folks
deal with this type of homology without resorting to
the type explanation which Darwin criticized as "And so
it pleased the Creator."

Brian Harper
Associate Professor
Applied Mechanics
The Ohio State University

"All kinds of private metaphysics and theology have
grown like weeds in the garden of thermodynamics"
-- E. H. Hiebert