Tuesday, June 19, 2007

Common Ancestry Merely a Theory

A second problem (for the first, please see yesterday's post) common among evolutionists is confusing the observable data--the evidence that needs to be explained--with the theory advanced to explain it. In a blog titled "Berra's Blunder" (6 May 2007), I gave an example of this. In that case, it was the fossil record that evolutionists tend to confuse with their theory that is meant to explain it. Despite the fact that the fossil record presents huge evidential problems for Darwinian gradualism, many evolutionists continue in this confusion.

But today I want to talk about another set of observable data that is commonly confused with a particular explanation for it. And that is the well-accepted fact that all living things share the same genetic code. Ask many folks why they believe the macro-evolutionary theory that all life shares a common ancestry, and they'll likely appeal to the shared genetic code, the fact (for instance) that genome mapping tells us that chimps and humans share something like 96% of their coding DNA.

Now, almost daily one can read about findings of new functions of the vast non-coding DNA (which was dubbed "junk DNA" when it was believed completely non-functional). And that finding of purpose for the "junk" should tend to undermine the evolutionist's confidence. (Of course, to a naturalist, the word "purpose" is taboo; nothing has a purpose, but rather just happens to serve a function. Purpose is a concept that has no place in the naturalistic paradigm.) But there's a bigger problem here.

And that is that the observable data--the universal genetic code--is accomodated nicely (indeed, even predicted within) the other reasonable theories about the diversity of life. The shared genetic code is the data set that needs explaining, and descent with modification (or common ancestry) is just one theory seeking to explain the data. Other theories that easily account for the shared genetic code include intelligent design, old-earth creationism (Christian monotheism), and typology, the view that Darwin sought to supplant with his theory.

Let me put it another way. Darwin's theory was never an attempt to account for the similarity among living things; it was meant to explain the differences. Ever since people have studied living things, they have recognized similarities, and grouped organisms with respect to their relative degrees of similarities. Since long before Darwin, biologists recognized chimpanzees as the most similar extant species to human beings. That being the case, the fact that genomics has allowed us to assign to this similarity a percentage (of the coding DNA shared) is at best (from the evolutionist perspective) neutral evidence. Indeed, it presents a further problem for Darwin's program, in that it shows how very, very similar we are in another physical measure, but gets us no further to understanding (on physicalist terms) why we're nonetheless such very different animals. In regard to this particular fact, the biblical account fares much better. It says that we are formed of the same matter as other animals, but are specially given an immaterial spirit that no other species possess. The Hebrew verbs involved are asah (formed from existing material) and bara (which denotes to create something new).

The point of this post is simply this... that all living things display similar biochemical elements and the same genetic code is a well-accepted fact. But that all living things have a common ancestry is merely one of several theories that attempt to account for this fact. To confuse the fact itself with the explanatory theory represents an error (albeit a common one) in critical thinking.


Pablo Honey said...

I liked your post. I have been slowly transitioning from Young Earth Creationism to Old Earth Creationism, and I was blown away by a recent article in the Washington Post about new discoveries regarding so called "junk DNA". It was interesting to ponder that not only could the genetic system be entirely more complex and efficient than the simple encoding of the four nucleotides (ATCG), but the system itself appear to be functioning at a level of complexity previously far beyond our current understanding. Oh what a marvel, our wonderful and complex universe!

Wouldn't it be a tragedy for mankind to discover ALL of the secrets the universe holds? What would we busy ourselves with then?

Washington Post Article:

Rick Gerhardt said...

Hey Pablo! Thanks for reading. There's a very interesting piece of research that shows the incredible design of the genetic code itself. I've hesitated to blog about it, because it would take a bit of genetic background to understand, but perhaps your interest in this topic will spur me to work on it. Thanks again.