Re: humans irreducibly complex?

Tim Ikeda (
Thu, 27 May 1999 22:44:48 -0400

Hi David,
your wrote...

> David Tyler wrote:
>> But is the gap to be found in the type of tasks genes do? If the
>> answer is "no", then why should creationists expect to see a gap
>> here?

Richard Daniel:
RD> What did you mean by this? If there is a vast gulf between humans
RD> and chimps, where else could it be but in the genes?

DT> This, Rich, is a major issue with some biologists. The
DT> basic assumption of many geneticists is that the genes
DT> control everything - but this IS an assumption. It has
DT> never been proved.

DT> I will draw your attention to "The doctrine of DNA" by
DT> Richard Lewontin. He is a marxist and an atheist - and so
DT> it should be clear that he has no religious axe to grind
DT> on this particular issue. I quote below from at review
DT> article at:

A good little book. I'd recommend it too.

[Lewtonin quote removed...]

DT> Lewontin is by no means a lone voice. From time to time,
DT> reference has been made on this list to others who hold
DT> similar views.

Yes, Lewontin makes good points about "DNA vs. destiny."
Many attributes of any particular organism are not determined
entirely by gene sequences but by other mechanisms as well
(eg. environmental influences, regulatory systems,... even
down to DNA methylation and chromosome packing). And we should
be very careful at examining genetic data with regard to
phenotypes. Relatively speaking, there are very few "simple"
cases where genotype -> phenotype linkages can be easily

[Aside: I do not believe most biochemists think we can
understand everything about an organism by knowing its
genome. Many are quite skeptical about genetic determinism,
particularly as it has been applied to complex traits such
as human behavior. Heck, we're still generally skeptical
about the usefulness of results from DNA expresssion

Yet, I suspect that Lewontin would not go so far as to say that
one could take the exact sequence of a particular chimp and through
extra-genetic manipulation (ie. no changes to the sequences)
produce a human. Because at some level, DNA is sufficient to limit
*some* destinies. This is, after all, what Lewontin studies.

Getting back to Mike Behe and IC... Mike has chosen very specificaly
to limit his consideration to biochemical systems which he hopes
can be readily analyzed. This is one of the reasons he did not
discuss something like the evolution of the eye -- too many parts,
not enough data. Garbage in -- garbage out...

I don't think it is too unreasonable to propose that if the
evolution of humans from a common ancestor of chimps required
impossible IC-steps, then we might be able to see this reflected
at the level of gene sequences and biochemistry. That humans have
systems which are IC is not disputed. Whether one can claim that
a particular IC system could not have evolved during the ape/human
transition is another matter entirely. If these IC-steps are not
reflected at some level of basic biochemistry and instead involve
other, extra-genetic, IC mechanisms, that's fine. However, we don't
really understand those mechanisms and so we do not have the means
to evaluate IC/ID claims which invoke extra-genetic mechanisms.

Tim Ikeda (despam address before use)

(Aside: Someone here mentioned that genetic determinism was something
atheists would like everyone to believe. Odd that he would read
your post, David, and skim over Lewontin's religious beliefs ;^)